Oil catch cans & fuel pre-filters

I was told a catch can was beneficial if you do a lot of stop/start city driving. I have never fitted either and never had any problems

"Modern diesel engines suffer from a condition brought about by an emission control process called Exhaust Gas Recirculation (EGR). In the EGR process some exhaust gases are piped to the air intake system, this modifies the combustion process thereby lowering Nitrous Oxide emissions produced. The hot exhaust gas contains carbon (soot) and other by-products of combustion that would not normally attach to the intake manifold if not for another emission control process called Closed Crankcase Ventilation (CCV).

Crankcase ventilation gases are also piped to the air intake system, this gas contains oil mist and water in the form of vapour. When the crankcase gases from CCV combine with the exhaust gases from EGR, the oil mist mixes with the soot particles to produce a mixture that attaches to the walls of the intake manifold. It’s the combination of the oil with soot that creates the problem. These deposits build up over time to a point where they severely restrict the flow of air, causing reduced performance and fuel efficiency.

Removing the deposits involves disassembly of the intake system from the engine, both time consuming and expensive. By installing an Oil Mist Separator, often called a Catch Can, the oil mist and water vapour are substantially removed from the combination thereby taking away the ingredient that allows the soot to stick. The result is that the build-up of deposits is GREATLY reduced."

180,000km and mine was clear

And cutting and pasting a speel from a company that wants to sell you a carch can is not a good source of truthful info.
https://www.dieselcare.com.au/service/catch-can-kits/

200,000 k on my Landcruiser and my intake was heavily choked up with soot deposits , I have now fitted a catchcan, should of done it from new.
I did fit a fuel pre filter with a water sensor alarm from new and has saved me from a contaminated fuel batch.

My sons girlfriend just got her new secondhand D4D Prado back from the diesel mechanic with a carbon deposit built up so bad that the vehicle would not run properly. She has about 230,000 k on it.

Ivan, yours might have been clean at 180,000ks but mine was showing early signs of build-up - brown staining and some crud build-up on butterfly and spindle - at 50,000ks. Easy to clean out of plumbing and intercooler, but not out of turbo or inlet manifold unless removed from car, otherwise there's a big chance of hard gritty bits of carbon ending up in the combustion chamber. Told by the service mechanic Isuzu generally starts to show signs about 40,000ks, thought this might have been an upsell for the next service so pulled inlet plumbing apart and saw for myself. If catch cans don't work and I have to keep getting inlet system cleaned every 50,000ks or so then so be it, but if a catch can will either lengthen the time between cleans significantly or remove the need for them altogether, then I'd like to hear about it from somebody who has first hand experience. Appreciate your comments, but unfortunately it's not the same for me.
Cheers Mal

John and Jan

What great insight you have... oh, wait, cut and pasted from a web site- good pick up Ivan.

For a moment there I thought highly of you lol

Your a nasty piece of work aren,t you eagle free. Obviously ignorance and sarcasm were the subjects you would have majored in. Maybe the mods who monitor the site can instantly remove any posts that disagree with your beliefs and although they are fact, they cannot possibly be true because eaglefree doesn,t believe it. Get on the Pajero forum, the Toyota forum and many other forums and there are many pictures and accounts of peoples manifolds being extremely full of crud. Bit like your mouth!

Mal Naomi
Oil in the form of mist going through first the intercooler and then the turbo is never a problem. Never has been and never will be. AS mentioned elsewhere in this post, if the EGR gas volume isn't allowed to create a high degree of heat to cook the oil mist then the mist simply goes through into the engine as it does on all engines of modern times. If the EGR is restricted, there is far less volume of carbon, direct from exhaust stream, entering the intake at select times.

No different to you previous words of assumptions and ridicule of my tug and choices. A short memory indeed

Can we save the personal feuds and abuse for twitter, please?

I think we moved on days ago Silkwood. Better you left it alone

Love your detail Frank

Thanks Frank, appreciate your opinion. Was told by Isuzu mechanic where I get car serviced city utes usually start showing signs on computer of intake buildup from about 40,000ks (sensor is setback in a hollow so it acts like a backwater and collects oil which registers before massive buildup in hoses). Pulled inlet hoses off and intercooler out and cleaned out but staining and buildup on butterfly convinced me to have job done professionally at the next service. Might be placebo effect, but thought fuel economy and performance better after clean out.
Cheers
Mal

Frank P
I don't quite agree with some info about the filtering of water. Nearly ALL modern diesel filters are made to, at least attempt to, extract emulsified water from the fuel stream passing through the filter. The filters have a feature which attracts water molecules and allows them to condense on the filter medium and precipitate into the bowl, which some strangely call a bowel, for later draining. Most filters of decent repute give figures of % of emulsified water which their filter can achieve, impossible to eliminate all emulsified water but the filters give it a decent try. A Water Watch unit only detects presence of visible water, ie globs of it, and so it drops to the bottom anyway. nothing wrong with having any form of water detection but it is only active for the stuff you can drain away. If any water detection system activates and water can be drained away it means there IS also emulsified water in the fuel and unless the filter attempts to remove it by it's design, the emulsified water goes to the high pressure pump element and injectors, both of which don't like the presence of water.

RMD,

I'm happy to stand corrected, and indeed, the description for a Fuel Manager filter claims up to 98% water separation efficiency.

Having read that, in 5 years I have never seen water in either the primary or final filter glass bowls - long may it be so. But it makes me wonder about the claim.

To diverge a little - my 30 micron pre-filter is due to be changed. I think you said that you use an 11 micron pre-filter and I follow the rationale you posted as to why. My preferred brand offers only a 5 micron final filter as the next step up from 30 micron. Stated fuel flow for both is 300 litres per hour. Do you foresee any issues or have an opinion in regard to replacing a 30 micron pre-filter with a 5 micron. I have no idea what the OEM filter is - I presume either 3 or 5 micron. Vehicle is a 2014 3.2 litre BT50, same as PX1 Ranger.

Cheers

Frank P
A 30 micron filter does reduce the number of large particles from getting to the OE filter but they are big in comparison to the tolerances of the system. A smaller size micron filter will do more and more as the micron size fitted is smaller. If the flow rate is sufficient, all should be over spec anyway, so there is not a problem with restriction. The Dmax runs around 35 litres and hour but peak flow is much higher through the filter and so a 120L/Hour filter is sufficient even for the times where high demand on acceleration is required. If it ever became a problem of flowrate then a larger flow rate filter solves the problem. The whole idea is to have, life of usage, without undue replacement of filters as they become contaminated. If the filter size/capacity of flow is far more than the requirement, then the fuel is lazy as it flows through and more particles can be caught than if running near max. Don't know specs of fuel flow through a PX Ranger but the engine size dictates the filter size as sufficient flow is needed. One bloke on here said to have a filter of small size so the OE doesn't have to be replaced. FIlters degrade over time and if left grossly over a reasonable time elapsed, the breakdown of filter medium becomes fed to the system. not good. Many filters are a grown algae of specific micron gap size and then the algae volume is killed/treated and used as a filter. very common. Usually, don't quote me, OE filters are 5micron or perhaps less. There is no reason why you cannot use a 5 micron as a pre, but if there is plenty of contamination, what usually passed through a 11 or 30 will be largely caught by the initial 5 micron pre filter and it will clog earlier and leave the OE almost untouched. Insurance? Many on here talk about stuff in tanks but seem to not realize the modern diesel is continually cleaning the fuel and tank as it passes ALL fuel through the primary part of the system about once very hour or so.

PX1 3.2 is actually a very clean motor. Mine has no mods and had its first egr system clean at 150 kms - hardly anything came out. The mechanic was most unimpressed haha. Coming from Toyota d4d I understand why you’d be gun shy though. Those and the Mitsubishi’s are dirty.

I can't let this go without a challenge . " All servo tanks have contaminates in them, but it is when the servo lets the tanks get low that the problem often raises its ugly head" I leased a servo for 22 yrs and would like to know where you got this information from. My tanks, if ever empty and the only fuel I ever run out of was diesel and at this time of the year due to harvest, had 700 lts left in the bottom. this was IF there was anything in the tank it wouldn't pull it up to the pump . I tested every Monday morning for water and this was documented . In all that time I never had a positive reading for water. If you ever got into the top of the tank & shone a light in they were clean as could be . Modern cars demand this. I suspect people making these types of claims are living in the very old past. Still like to see evidence to back these type of claims up.
Gordon

Fuel distributor at Monto, Croakers fuel distribution in Mackay + numerous tanker driver that I would chat with on the road.

Here is a little backup evidence and maybe not all servo owners are as diligent as you and follow beat practice.

This is as good a source as you will get and not from the distant pass.
.
Link

9900eagle
Using a 30 micron filter isn't going to be of any benefit to a CRD filter. Most of any consequence will simply pass through it. Please understand filtering. The pickup in a servo tank is always near the bottom, How will low level be worse??????
Please explain how intake contamination goo affects an Auto Trans, who believes that??????????????? ALL intercoolers without a catch can fitted to blowby stream, simply run ALL their lives with NO problem. Include all busses and trucks there as well. It is EGR Exhaust GAS heat which is the problem not the blowby oil mist. Please understand that too.

Evidence accepted What can I say ! The 28 on the motorway is what you would expect if fuel was contaminated. Can not understand only 1 getting bad fuel . I used to shift almost 70,000 its of diesel a week on average so it was always turning over
Gordon

As I understand it RMD, the problem peculiar to modern common rail turbocharged diesel engines with EGR is a combination of BOTH the oil mist and carbon deposits in the recirculated exhaust gas - without EGR the oil mist goes thought the engine without causing any problems as you say, without oil coating the inside of the inlet plumbing the carbon in the exhaust gas would also pass through the engine without sticking and gunking up the inlet system. Stopping the exhaust gas recirculating is illegal so the only legal option is trying to stop the oil mist.
Cheers
Mal

RMD

Point 1. The contaminates are normally heavier that diesel ie. water so guess where they sit.

Point 2. I never suggested a 30 micron filter, all I did was give the OP a choice and let him decide after he does some research into the effects of placing extra restriction on his particular vehicles fuel system. I actually use a 5 micron filter. A 30 micro one will have an effect as it will catch any larger particles and not let them block the oem filter.

Point 3. I think you best go to an automatic transmission repair business and ask one of the first things they do when a modern transmission is playing up is look at the sensors and restriction in the inlet manifold, because that affects what information the control modules send to the engine and the gearbox. There is a very close tie between automatic, automated manual transmission and engine output problems caused by buildup in the engine intake. So it maybe best to keep your nasty ??????????? to yourself.

Point 4. having had just a wee bit to do with trucks, I have seen non egr engines down on power and when investigated, it was found the intercoolers had a lot of oil in them. Intercoolers cleaned, oil separators fitted and engines back to their normal power output.

You have a happy day and just be a bit more civil next time.

9900 eagle
?????? is a query system to ask people to consider what they are saying, WHY on earth do you interpret it as NASTY?
1, The contaminants get sloshed around in a tank unless parked at home. therefore the stuff, water and particles get drawn onto the fuel system and it cleans it via the use of a filter and returns it to tank. Is there another way it happens ? + ? one more for the thinking to start.
2. A 30 micron will allow LARGE particle to the OE, anyone who has a consider of the issue will use a lesser size because you don't want LARGE near the OE is at all possible. OK if it stops it, rooly baad if not. Yes anyone can decide.
3. What you are saying about auto is actually the engine sensors affecting engine operational parameters and if the auto become affected too because of the wrong info the engine must have also be subjected to the issue first up. So the ECU operation is affected not the auto, it is simply a receiver of info and remains unaffected. ie, no faults in auto.
4. OK, you clean the oil out of an intercooler, it does precipitate there, and now your engine runs ok again. What happens now when the engine now running and feeding normal amounts of oil mist as usual into the intercooler. isn't it the same situation as before the oil was cleaned out. How long does it run before low power again. that is a silly situation. Perhaps a drain tap on the intercooler is a good idea for those vehicles which accumulate oil to extreme. The oil only builds up to a small level UNLESS the design allows a massive build up and the airflow cannot continually flush it out and keep it at a small amount. Something wrong there if that can happen.
Just take what is being said and evaluate it without undue passion and over sensitive offence.

No, the question marks stand for bullshit, plane as day.

About the auto, what happens id often the engine doesn't throw codes but the gearbox does in the form of powertrain light coming on and it is actually the engine that has the problem.

Didn't you read where I said they cleaned the intercoolers and fitted oil separators.

On the last remark ,the only person that can tell me what to do is my lovely wife.

qldcamper, I have to reply to your comments. "Yes the build ups exist, but do they lead to problems?" Have a look at the pics of manifolds nearly completely choked and tell me that isn't a problem or will not lead to a problem????? Another, "As for prefilters, i felt the money better spent on a long range tank so i dont have to fill at dodgy places and make a point of looking at the filter bowel every morning and carrying a couple of genuine spare filters." You don't have to fill at dodgy places to get a gut load of water when you refuel, many reasons for water in fuel. Also by the time you check each morning, damage may have already been done, hence the reason the better pre-filters have an alarm fitted to warn of water.

Just stating my opinion not looking for an arguement. Way too much scare mongering in forums. If you worried about everything that might go wrong you wont enjoy the vehicle.
Spend your money on things you think you need not trying to avoid what happened to a very tiny percentage of vehicles out there.
Keep your fuel reciepts, they all have insurance that covers damage from products they sell cause. Other than that i trust the OEM filter and seperator with its very sensitive warning system.
But thats just me, you do what you think is necessary.

John
The ONLY reason there is a build up of gunk is because any oil mist is turned to goo and gunk by heat. That heat comes from the EGR hot exhaust gasses. If reduced in quantity there is insufficient heat to do any baking in the inlet manifold. Most water in visible particles doesn't go through the filters of the fuel system very easily, BUT the emulsified water in any fuel does travel through. Having a warning system of water is a great idea, BUT, that only warns of large amounts which usually drop to the sump bowl. Good to be warned empty it out if there but what has already gone past to the high pressure pump and injectors is contained within the fuel molecules itself. Water detecting systems don't see that. Water condensing filter membranes of the filter does catch most of it. Having two or larger filters ensures more emulsified water catch. It isn't the engine we are protecting here, it is the fuel system.
The OE filter and water sensing is nothing fantastic, adequate bit can be enhanced.
If you talk to Cornell diesel or others you will realize the failures are not a tiny percentage. Toyota filter change regime almost ensures failure. Some owners have been burnt.

Hey Matthew, are those figures 50ml and 35ml? I get about 20ml every 10k km on my BT50.

You're right about the all-in-one bracket - on the BT50/Ranger anyway. It's a neat job, but servicing the pre-filter requires removal from the bracket. Not a big deal, but a bit inconvenient.

I can get to the Provent element without too much difficulty..

Hi Frank
You did read right 500ml for DMAX for 22,000km and 350ml for the PJ Ranger 20,000, of that 50ml was water as she does shift work early starts and late home getting a bit of condensation.

Matthew G3
Getting less blow by mist on a vehicle which does short trips means it is running cold or colder more often and so will not oil mist anywhere near as much as a long hot running engine. The amounts are a bit meaning less in a way because the comparison isn't same/same situation.
You WILL get less blow by, less mist if the engine oil is a good quality which seals the rings better. Blowby and oil quality are the two factors which determine what is puffed out, hot or cold.

RMD the DMAX is the opposite long hot run no blow by on short runs which it does a lot school runs just hitting normal temp on return it has a lot of oil mist. I was just showing different engines have different amounts in the catch can. The wife does 16km return 10hrs shift.

Matt

Matthew G3
It is impossible to stop blowby, there is always some. Oil mist when relatively cold condenses easily and will present as more. but when hot there has to be hotter mist which can and does go through a catch can tp some degree and you don't see than caught, so What is really happening?
Also, you have two different engines and two different use patterns and two different grade oils at play. I defy anyone to quantify a comparison. What oils are you using? it has a BIG bearing on blowby and use and development of oil mist. Different grades behave differently. If dealer serviced the oils will be a relatively cheap oil which does the job but not ideal.

YES! Going against the spouse' viewpoint can be more costly than injector system repair.

Rocco2010 and RMD, yep, duly noted. As Naomi is the keeper of the bank account details, a pre-filter is a given if I ever want to fit a catch can!
Cheers
Mal

Dave I think your right, as discussed on this forum a few years ago, the extra filter must not interfere with the pump pressure it can cause problems , so the right filter is a must!.


Cheers Axle.

Axle
That is a strange thing to say. Anyone who fits a pre filter should routinely make sure the filter being fitted cannot and will not interfere with the system operation. ie, a bit of knowledge of the whole process before fitting! Why would you do it any other way? If the filter flow rate and it's position in the fuel stream are sensible there is no negative effect, just better graduated filtering and water collection ability.

That's what Im saying RMD the right filter has to be fitted!!!.

Talk about saying strange things!. Why would you do it any other way?

Not everyone is up to speed on everything!


Cheers Axle,

Phil G.
"Can happen for lots of reasons - catch can is full, hoses kink, hoses are hooked up backwards, filter is gunked up. The pressure relief valves in many catch cans may not be big enough to reduce the backpressure. These are good reasons why vehicle manufacturers do not support the fitting of catch cans."

Hoses hooked up backwards...can apply to any piece of equipment if not installed correctly! The Provent has a safety valve that allows the catch can to release pressure if for some reason the catch can is blocked. If the catch can is full of oil you either have a major engine malfunction or you have not checked the catch can for a very long time. Which catch cans are you talking about when you say they may not release the pressure? You state "many".

My Provent filter is 5 years old and been cleaned probably 4 times. I know for a fact that if I hadnt of cleaned it at all it would not affect the cans performance..It keeps the oil suspended till it drips into the collection reservoir. It does not collect crud.

Nearly every vehicle manufacturer does not support engine accessories being fitted to their vehicles. .I dont know of any that put a pre fuel filter on as standard. None that tell you how to remove the egr, which is illegal anyway. If the original manufacturers equipment is so good..why even bother adding a pre fuel filter as well? I run a 3 micron secondary fuel filter as I also believe in preventative maintenance.

I have the egr turned off and the pro vent fitted and as I said my oil is extremely clean after 5000klms. I,m not saying a catch can will completely stop your manifold from blocking but it will go a long way in helping. Lets not forget that the catch can is legal. The egr mod is not. Your diesel shop is wrong also! I have seen photos of forum members whose manifolds have been completely blocked at 150,000klms. Up to 50% blockage at less than 100,000klms!

Phil G
IF and only IF a catch can became full will the system alter in any way. IF it is full then as additional oil mist enters the catch can some droplets will be expelled from the can and into the intake and turbo compressor wheel.ie NORMAL operation. In ALL intercoolers there is OIL condensate and droplets exit the IC at times because of the wind speed. ie self cleaning, NORMAL again. Never a bother to any turbo. The reason we have LOW ASH oil for DPF vehicles is because of the oil passing through the system and becoming ash which MAY accelerate the DPF restriction.
ANY oil going into the intake will/may affect the DPF build up. A working catch can minimizes that. I can't remember when a blow crankshaft seal because of crankcase pressure build up, maybe it happens but is rare indeed.
If a DPF becomes restricted the engine becomes constipated and reduces output, a bit like humans really. How can that blow crankcase seals?????

My neighbours Navara had I think approx 130,000km and the intake was around 30 percent blocked a couple of yrs ago. I had a look and it's not something you want in your engine. I mentioned to him about fitting a catch can don't think he bothered.

Hoses hooked up backwards and has kinks in them causing issues well only a fool would do that and not expect something to go wrong that's a no brainer. It your garden hose has a kink in it stopping the flow of water does that mean all garden hoses are no good and should not be used. It doesn't take much to set one up correctly and if you buy a quality item like Provent 200 it has directional arrows and relief valves and there is no reason you have to kink hoses to fit them.

Your mechanic says around 250,000km you may expect issues I would ask why not try and prevent it from possibly happening at all because it shouldn't happen and car manufactures should be held responsible. Modern engines should easily last for 1,000,000km plus without issues due to build quality and not have their life expectancy cut way short because of pollution gear that is suppose to be good for it when it isn't.

As a warrant officer of engineering in the RAAF told me in 1973 as a young bloke- the manufacturers are far more qualified to know if that modification was needed. Never for got that. Only few mods are proven imo
Tony

Eaglefree that might be the case in the military where things are built to a performance level but in domestic circles they are built to a pricepoint not a standard and also need to meet external compliance issues which are often not in the best interests of the vehicle.
Dirty fuel is not going to be the manufacturers problem but the consumers so taking preventative measures can be prudent
Likewise EGR blockage issues won’t come to light until after warranty runs out so once again a consumer problem
There are countless documented issues of these types to know they are not scaremongering stories to sell snake oil products

Fair comment Alby

However you’d think one, just one manufacturer would install one standard if catch cans are efficient and fool proof.

I don’t know of one
Tony

They don't because it defeats the purpose of the EGR which is to feed exhaust gases back into the induction system to reduce emissions on trailing throttle - the catch can catches most of the heavy particles so the effect is reduced.

Catch cans have been around for a long time. I first used one 20 years ago.
But there is still no objective evidence that you can prevent black grunge in the intake.
Sure they do catch some oil and you drain it (which makes you feel good), you'll never know how much more still gets through to the intake.
I have no commercial interest in the comments I make. But many do - the Youtube crowd, Facebook, magazines, TV etc etc promote them with zero evidence they reduce the grunge in the intake.

No manufacturer I know of fits a catch can. Toyotas now come with a factory 7 year engine/driveline warranty - they must know something.

EDIT: just to add, I had a HDJ79 for many years and cleaned the black grunge out of the intake when it had 90,000km on the clock. I disabled the EGR and pulled the intake apart again 100,000km later and it was clean. Got to stop the soot getting in there. No point in just fitting a catch can.

This catch can discussion reminds me of some car forums. One question was in a commodore forum aksing about oil type used in the T5 manual gearbox.

Some said "I've used normal gearbox oil for 5 years and havent had a problem"

The manufacturer recommends auto transmission fluid dextron 2.

Now, just because someone hasnt had a problem doesnt mean he/she wont in the near future. Internal wear can be going on without the owners knowledge right?
So I think- just use the oil the builder told us to use.

Crud build up in a diesel intake- what real proof is there to say the catch can prevented it? I'd like to see it in writing by highly qualified engineers not heresay. Not my mate did this or that. Or crud was less this time to clean out but in the latest period of driving you did more highway cruising than city driving.

Until then, the hard irrefutable evidence comes along its mere speculation.

"They don't because it defeats the purpose of the EGR which is to feed exhaust gases back into the induction system to reduce emissions on trailing throttle - the catch can catches most of the heavy particles so the effect is reduced."

I don't follow you Ozzie. Catch cans do not work on the exhaust gases, they work on crankcase gases. They do not affect EGR. All they do is try to remove oil and water vapour from the crankcase blow-by gases before those gases are directed into the inlet system where they get cooked by the hot recirculated exhaust gas.

A catch can by itself does not inhibit exhaust gas recirculation or reduce its benefits.

Phil G
"EDIT: just to add, I had a HDJ79 for many years and cleaned the black grunge out of the intake when it had 90,000km on the clock. I disabled the EGR and pulled the intake apart again 100,000km later and it was clean. Got to stop the soot getting in there. No point in just fitting a catch can."

I think you have highlighted the real problem. It is EGR that is causing the problem that people are trying to address. There are two ways of doing it.

One is by disabling EGR. Most effective, but illegal.

The other is by using a catch can to capture the oil mist that the EGR converts to baked-on crud in the intake system.

Exhaust gas recirculation was introduced in order to reduce nitrous oxide pollution. It works by cooling the combustion process and this reduces the nitrous oxide output.

By law, crankcase blowby gases ( pollutants in themselves) must also be re-directed into the intake stream to be burnt, rather than being vented to atmosphere. They contain oil mist as well as gases that have leaked past the piston rings. By itself, oil mist in the intake stream is harmless, apart from perhaps depositing over a period of time some pretty wet grunge on a couple of sensors - grunge which is easily cleaned off. No big deal there, IMO. The requirement to direct crankcase gases into the intake stream was set some time before EGR became the norm.

EGR does work, in that it does reduce nitrous oxide pollutants. However it comes at a cost. The hot recirculated exhaust gases are injected late in the intake stream, before or at the intake manifold. They cook the oil mist that is already present in the intake stream, forming solids that get deposited on the walls of the intake system downstream from the EGR injection point. As others have posted and pictures have shown, left long enough the deposits will build up enough to restrict intake flow and cause issues. The speed at which this occurs depends, among other things, on the amount of blowby the engine produces, and therefore the amount of oil mist in the intake stream.

To prevent the problem, either disable EGR and stop the cooking process in the intake stream (illegal but effective), or remove the stuff that gets cooked by using a catch can (less effective in the long run, but legal).

As to why manufacturers don't install catch cans - well call me cynical if you wish, but my money says it's an accounting decision, not an engineering one. The effects of not having a catch can won't show up until well after the warranty period and it's a nice little earner for dealers or the repair industry when it comes time to diagnose and fix an asthmatic, poorly performing engine.

The original poster wanted to hear from people who have actually fitted and experienced the benefits/issues with these filters.

The following article is from a mob called MOROSO. A highly respected company that has developed many high performance parts suitable for street cars to high performance race cars.

https://www.enginelabs.com/engine-tech/engine/catch-can-why-direct-injection-makes-them-a-must/

I should have also included a photo of the earth as seen from the moon....but I doubt that some would still believe the earth is flat!!

My 35 y/o son is a diesel fitter, I had a conversation with him about catch cans again because he tells my I should one have, and I do. He said yesterday that Fleetgaurd & Cummins are now fitting a type of catch can to their motors and that they drain back into the crankcase. he also said he had read some top end 4x4 (SUV) manufacturers were looking at catch cans but has been unable to find the article. He wasn't sure if it was on the net or a trade publication . I had the injectors on my last patrol done while interstate and the Injection service that done the job recommended that while nissan filters were dear he said for 3LT CRD that was the best filter I would get and not to bother with prefilters, but that's only for a Patrol My 2 bobs worth. PS my son doesn't believe in pre-filters either

Gordon, Cummins learn their lesson with their early isx erg engines, it cost them. They are a great engine and now the pick of the American transport engines and with very good filtration.

Just my take on prefilters, my oem filter is a pitta to remove in the paddock, no problem in the shed but if I service the oem filter out on the track I risk introducing contaminates into the high pressure pump. With being able to service the prefilter I don't risk that, because any dust that manages to get into the system at the prefilter will be caught by the oem filter before it gets a chance to get to the high pressure pump.. It has a much larger surface area and a large water trap, I also have a water watch which warns if water gets passed the prefilter and I can shut down before it reaches the oem filter. Many years ago I had a Racor filter similar to this on a truck and it used to filter out a lot of crud and nasties. Racor truck filter link

Over kill probably, but I am happy and content. Well a lotto win would be more smiles.

Thank you for the responses guys. I know from past experience on my DMAX the inlet system is starting to clog with gunk after 50,000klms, not much build up mind, but enough to make a noticeable difference to performance and fuel economy once inlet system is cleaned (build up is slow so drop off in performance and fuel economy is so gradual it's imperceptible). Cleaning intercooler and hoses to and from is easy, but having to remove inlet manifold to do the job safely and properly every 50,000klms would be a pain in the wallet,.Draining a catch can every few weeks and changing its filter every 40,000klms would be so much easier and cheaper. From the sound of things, while they might not be perfect, catch cans are better than nothing and if inlet cleaning is still occasionally needed, it'll certainly be at much greater intervals then 50,000klms. A catch can also won't void my insurance policy like blanking off the EGR will (by plate or cable to trick sensor) if its discovered. I think FRANK P was on the money with why catch cans aren't OME. Also, they require the vehicle owner to dive under the bonnet every so often to drain them and car manufacturers really don't want owners under there having a fiddle.
As for the pre-filters, I think I'll have to do bit more research on appropriate filter micron sizes and water alarms. I have a 142lt long range tank but I still have to fill up in out-of-the-way places occasionally. I have noticed some of the aboriginal communities and other remote WA refueling places now have plug-in above-ground modular tank with pump units that are delivered on site as a complete unit which is filled and then plugged into power to operate. Different units for diesel and Opal, etc. Over time might be some minor water risk from condensation, but certainly not the same risk of contamination as old underground tanks.
Cheers,
Mal

'Servicing the intake every 100,000klms is all that most need as an alternative to catch can use.'

Vast majority of average diesel drivers wouldn,t have much idea about how their car works. They book it in for an annual service and expect the service centre to take care of it all....and we all know how often that can go haywire. If your happy to pay anywhere from $500 to $1000 for a manifold clean every 100,000 go for it eh? Otherwise you,ll know when there is an issue when the car goes into limp mode...and generally miles from home and at a really inconvenient time...plus the diagnosis may not be correct...but hey its only money and they are still printing it!

I,ll have to disagree with you Swampy with regards to the 5w/30 oil. Like a hell of a lot of other diesel owners I use Valvoline 5w/30 full synthetic and it does the job no worries. I change oil at around 8000klms only because I tow a lot. Otherwise 12-15000 would be fine using a full synthetic.

It has happened to me before and had trouble getting the fuel back up through the system again.
I have had a successful outcome on two occasions with my Landcruiser taking the fuel cap off and pressurising the fuel tank with my air compressor with the aid of a rag to get a bit of a airtight seal.
Easily done and it did the trick

I've never run my BT50 dry until it stops - I cannot see that doing any good to parts that are designed to run in fuel for lubrication - but I have changed filters and have had to bleed the system. The BT50/Ranger bleeding process is easy. Turn the key on (but don't try to start it.) Leave it on for 20 seconds then turn it off. You can hear air being displaced from the empty filter. Do that three times then start.

I have no idea how to do this in later vehicles with keyless start.

There is nothing in the owners manual about this, and nothing in my repair manual on a disk. I got it from the newranger.net forum. It has never failed to work.

Frank P
Does your BT50 have an intank fuel pump? Sound like it does, similar the early Dmax vehicles. Self bleeding they are.

Deejay
Wouldn't it be better for anyone wanting to learn diesel bleeding to simply open appropriate breeders and sequencially have fuel exit from each one. That way no air is introduced AND the same situation is happening as it would IF the system required bleeding. When changing filters,I have a switch and two wires to take the place of the main terminals of fuel pump relay. Closing the switch allows me to switch on the intank pump and bleed my aux filter and main when required. Easy as for purging control.

RMD

"Does your BT50 have an intank fuel pump? Sound like it does, similar the early Dmax vehicles. Self bleeding they are."

When I turn the key on there's a fair bit of faint whirring going on both around the tank area and in the engine bay. The louder is around the tank. It has to be self-priming, so I presume what I'm hearing at the tank is an internal pump. Heaven knows what's going on in the engine bay pre start to cause the noise there. Whatever it is, it seems to work - thankfully :-).