EGR horror!

Submitted: Thursday, Feb 05, 2015 at 11:42
ThreadID: 110999 Views:7146 Replies:9 FollowUps:8
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Hey guys just thought I would share my experience of removing my intercooler (install a new one) on my 2011 2.5TD D22 Navara, and too my horror the black crap that was hiding in my intake actually scared me, now I am no mechanic and don't pretend to be but have basic knowledge from playing with my R32 skyline.
When I initially pulled the cooler off there was a light coating of black sludge around the piping which didn't surprise me too much but i thought id stick my finger in a see whats actually a bit deeper in the pipe and wish I didn't, but glad I did, very thick black sludge.
I had a block off plate that I bought a while ago and was tossing up whether to install it, there are a lot of contradicting stories and ended up just leaving it off.
But I can tell you know do not listen to what you read, go right now and remove your intake/check piping and if its the same as mine you will not believe your eyes. Now this could be an isolated instance but my car is relatively new, never missed a service and has 80,xxx kms, but have also heard of many people having the same issues.
Now I'm not telling you to do anything, but after what I just saw I will not think twice about installing my blocking plate.

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Reply By: zimbo FOX - Thursday, Feb 05, 2015 at 11:43

Thursday, Feb 05, 2015 at 11:43
AnswerID: 545396

Follow Up By: cruza25 - Thursday, Feb 05, 2015 at 13:20

Thursday, Feb 05, 2015 at 13:20
the oil is from the rocker cover vent , not the egr.

on a prado the experts recomend to fit a genuine (beware of the cheap chinese copies ) provent 200 catch can with filter . This takes out all the oil. The soot from the egr mixes in the intake manifold with the oil and eventualy blocks the air flow over time.

By filtering the oil out , the soot goes right through and gets burnt as per design.

Somtimes the blanking plates cause error codes on prados but may be ok in the nissan.

FollowupID: 832962

Follow Up By: zimbo FOX - Thursday, Feb 05, 2015 at 21:42

Thursday, Feb 05, 2015 at 21:42
Checked the rocker cover, didn't have anywhere near the black stuff I found in the intake, also taking off the egr piping found more of it, I put the plate on so will see what that does, no error codes came up
FollowupID: 832992

Reply By: TomH - Thursday, Feb 05, 2015 at 13:26

Thursday, Feb 05, 2015 at 13:26
My Cruiser was like that I pulled the intercooler pipes off and cleaned them all. Did it again.

I went to Toyota and asked them about it and was told Perfectly normal so didnt worry about it any more.
AnswerID: 545401

Follow Up By: Member - Bookleaf - Saturday, Feb 07, 2015 at 22:26

Saturday, Feb 07, 2015 at 22:26
Correct, perfectly normal,
What they did not go on to explain is that it will eventually build up and cause engine running problems (see MANY threads here and everywhere.)

They then can hit you with a big bill to clean it all out!!!

Concern that it is present IS needed.
FollowupID: 833163

Reply By: pop2jocem - Thursday, Feb 05, 2015 at 15:28

Thursday, Feb 05, 2015 at 15:28
EGR systems were introduced to assist in the reduction of nitrogen oxide gas in the exhaust. Basically inert gasses from the exhaust are introduced into the combustion cycle to reduce temperatures that allow the formation of this bye product. Unfortunately this also reduces the performance of the vehicle to a degree.
I believe that like tampering with any other of the emission controls of an engine, this, strictly speaking, is illegal. Probably why a fault is recorded on the ECU of many vehicles.

I have read that research into other more efficient emission reduction strategies are making the use of EGR less favourable.

AnswerID: 545407

Follow Up By: pop2jocem - Thursday, Feb 05, 2015 at 15:40

Thursday, Feb 05, 2015 at 15:40
Just as an addendum, the reason why we now have particulate filters added to the exhaust systems of diesels is that by using EGR the combustion efficiency is reduced. This allows greater particle (soot, carbon) production. This harmful emission must therefor be filtered out.
More and more engine manufacturers now specify fully synthetic lube oils. I suspect this is because of the increase in particles being washed down the cylinder bores and the extra dispersant ability required by the oil.

FollowupID: 832974

Follow Up By: zimbo FOX - Thursday, Feb 05, 2015 at 21:49

Thursday, Feb 05, 2015 at 21:49
I don't disagree with the legality of blocking it, or do I pretend to know a great deal about the whole system, all I know is that it can't be good for the efficiency of the engine and the engine in general. If I found that black substance in the intake of my Skyline the engine would have already blown.
It surprises me how different everyone's view on the whole egr system, it worries me a bit that there is so much contradicting evidence to both sides.
Will have to pick my mechanics brain tomorrow.
FollowupID: 832993

Follow Up By: pop2jocem - Friday, Feb 06, 2015 at 02:43

Friday, Feb 06, 2015 at 02:43

Legal or not, many do the mod of fitting a blanking plate. With the vehicles that then do record a fault code some fit a plate with a small enough orifice to prevent the majority of the exhaust gas passing into the intake system but large enough to keep the system happy and not record anything.
Does EGR contribute to a reduction in efficiency? In my opinion it must.
My take is that, legality aside, fitting a blanking off plate either a complete blank or the control orifice variety will increase the operating efficiency and should keep the lube oil in better condition for longer.
From a strictly legal point of view you are reducing the effectiveness of the manufacturers attempt at NOx control.
By all means have a chat with your mechanic, but at the end of the day the decision is yours.
If it's of any comfort though, you ain't alone. (;=))

FollowupID: 833000

Follow Up By: Ron N - Friday, Feb 06, 2015 at 16:28

Friday, Feb 06, 2015 at 16:28
EGR can be rated as a modern "failed technology". There are plenty of engine manufacturers who don't use EGR technology.
It's a dead-loss idea, and it provides nothing but headaches and increased maintenance and repair costs, to anyone who owns a vehicle fitted with it.

Cheers, Ron.
FollowupID: 833051

Reply By: Michael ( Moss Vale NSW) - Thursday, Feb 05, 2015 at 17:42

Thursday, Feb 05, 2015 at 17:42
So you didnt need the EGR? Michael
Patrol 4.2TDi 2003

Retired 2016 and now Out and About!

Somewhere you want to explore ? There is no time like the present.

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AnswerID: 545411

Reply By: Batt's - Friday, Feb 06, 2015 at 00:46

Friday, Feb 06, 2015 at 00:46
It's becoming pretty common these days for people to block it off and put a catch can on and plum it back into the sump or just put a tap on it so it can be drained occasionally it may be illegal but it will save your motor.
AnswerID: 545434

Reply By: Rangiephil - Friday, Feb 06, 2015 at 10:16

Friday, Feb 06, 2015 at 10:16
EGR is only open when the engine is under light load say cruising at 100Kmh.
Under any heavier load it is closed by the ECU.
While the EGR valve can be a restriction in some engines, it is really doubtful that the EGR valve will cause a drop in efficiency of the engine under full load conditions, as it is closed.
In my case I took off my inlet manifold on my Land Rover TD5 at about 140Kk and there was a lot of coke on the valve itself and that black crap in the manifold.

However a clean with a scraper and Gerni saw most of the coke transferred to my face and hair in no time.

The main thing to watch with aTD5 anyway is that the MAP sensor does not become gunged up. I believe that this is also a problem with VMs in Jeeps, 3.0 Patrols , and Mitsubishi Pajeros and probably others.. My wife's cousin had his Mitsu go into limp mode while going up Cunningham's gap towing a van. Mitsubishi replaced the manifold with a relocated MAP AFAIK .

I have left mine in place and just monitor the MAP , and using full synthetic diesel oil it has not become coked again in 35KK. They EGR tends to coke up cars that are not run hard eg stop start around the city.
I have a delete kit but I am loath to fit it, because of possible fault lights and the fact that in a Land Rover the bolts holding the EGR plate to the exhaust manifold are known to shear off when being undone, which would be sure to happen to me.
And I don't really think it affects performance one bit.
Regards Philip A

AnswerID: 545462

Follow Up By: Rangiephil - Friday, Feb 06, 2015 at 10:22

Friday, Feb 06, 2015 at 10:22
BTW, most EGR is fed in after the intercooler.

Oil in the intercooler is usually from the crankcase breather as previously posted.

One ( the main?) cause of excess oil in the inlet manifold is degradation of the Manifold Depression Valve or otherwise known as the PCV valve.
This closes off the crankcase vent under high manifold vacuum, ( as it is pre turbo, that means high load) even on a diesel, and stops excess fumes from entering the manifold.

If it is degraded/old it will not stop a lot of the oil entering the manifold.
They are usually cheap and a good investment if a car has done over 100KK.
Regards Philip A
FollowupID: 833011

Reply By: zimbo FOX - Friday, Feb 06, 2015 at 21:36

Friday, Feb 06, 2015 at 21:36
Day one with blank plate, no notice in performance but I didn't really expect anything. I've noticed on idle it sounds better and has a bit less vibrations coming through into the cabin. Also acceleration off idle seems smoother up to boost although no notice in boost coming on earlier. As for fuel have not tested yet
AnswerID: 545515

Reply By: Bigfish - Saturday, Feb 07, 2015 at 11:31

Saturday, Feb 07, 2015 at 11:31
Just fitted SPV mod. This was on a 2014 Pajero. Plug in 30 second job.

This module (variable resistor) works by telling the sensor in the EGR that the motor is cold which ensures the butterfly in the EGR stays closed.

By closing the EGR the engine will run hotter and certainly cleaner with no recycled gases. Fuel consumption should be slightly better.

Provent 200 fitted as well. The filling of the manifold with dirty black coke is well known on some diesel motors. Mitsubishi have even replaced some under warranty.Mine is only a new car but I believe in prevention rather than cure. The Pajero Club of Vic is an excellent forum on this subject of EGR.

AnswerID: 545534

Reply By: garrycol - Saturday, Feb 07, 2015 at 12:28

Saturday, Feb 07, 2015 at 12:28
The gunk you describe is pretty standard for EGR fitted diesels - certainly my RRS diesel inlet manifold was the same until I blanked it. My sludge was about 1cm thick after only 60,000km. The main issue for my engine (and I guess the same other CRDs) is that it can cover the Manifold Air Pressure sensor and cause issues bit this is a two minute clean.

In general terms, the egrs are open on trailing throttle feeding in exhaust gases back into the low power combustion process to reduce emissions. There is unburnt fuel in this gas and other "slush" and it is this that accumulates in the inlet system - any that gets into the engine is burnt off.

On full or power throttle the EGRs are closed and the engine burns clean air from the air filter.

That is a very general description only and it is far more complex than that.
AnswerID: 545537

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