Shell Helix Ultra 5W-40 in a 3.0Tdi Patrol

Using the ELF would the 3.0L be in front of the 4.2 as the 3.0L only has a 17:1 compression ratio vs the 22:1 in the 4.2?

Quite correct Jeff, the ELF is more appropriate for hi reving engines (>8-10,000)
i.e. race engines.

Not all the factors go against the 3lt in fact its a superior design in many ways - it is simply as has been summed up by many, a little overstressed for its load, and this is complicated by lack of sufficent gearbox matching.

Simply a 6 speed manual or the existing patrol 5 speed auto would see it as a better overall package.

Robin Miller

Yeah, I just don't think that people blaming the fact that it's a smallish 4cylinder motor that's "overstressed" is really accurate.

I mean it's not like they just got a standard Direct Injected diesel and whacked more compression and higher turbo boost on it to get more power.

It's been completley re enginerred to get more power out of it by using clever technology in the turbo and primarily to get a better cooler fuel air mix before combustion. That's where the power is comming from, not by "stressing it".

The problems with the ZD30 are poor design, full stop! It's a clever design that had potential, it just was not tested well enough before being mass produced and released into the market IMHO.

It's got more than enough power without having to work hard to lug that big bucket of nissan bolts around. I mean it's got WAY more power than the old 4.2 naturally aspirated diesel had, so in these "over stressed" mongers minds this would surley mean that the older 4.2 was just way over stressed because it had to work too hard. BULLCRAP. You can't tell me that the 6cyl 2.8TD was any less stressed can you? That thing was overworked, this one ain't.

Anyone want to tell me what boost pressure the ZD30 is running stock? I'm sure it's not overly high... Compression is only 17:1, so where is all this "stressing" comming from? The only stress in a ZD30 is the drivers wallet everytime it makes a cloud of smoke and stops working!

These "stressed too much" theories just don't add up I'm sorry.

But you're right, the gearing on these rigs is CRAPOLA. That really needs some serious re configuring.

I reckon Nissan will just chuck the ZD30 for a new common rail variant in the near future anyway.

But on the upside, there are going to be heaps of cheap ZD30 GU's around for me to snap up in the next 5-10 years when the wheels fall off the surf. I can do what Bilbo did and buy one real cheap, get it flat tray'ed to Brunswick and get them to put a 6.5L V8 turbo in it. ;-)

Hi There Jeff

I think where gunna have to disagree on a couple of points - I don't think that 3lt is a bad design. I believe that it is essentially - to small an engine in to big a car.

Although it really is a little more subtle than that - but thats close enough for an email post.

The engine does have less power than the 4.2 - now before you read off the figures that say 116kw (2003) against 114 for 4.2 - its not really read that
way. Those are just "image" peak figures that people quote from sales brochures, the real motive power is measured by measuring the area contained under the horsepower curves.
When doing this you immediatly smooth out the peak in the 3lt power curve and see that it has in fact less "average power" for want of a better term.

On the 2.8 - yes I will say that it is less stressed than the 3lt.
The stress measurement that is relevant is not the compression ratio.

Trying to keep this short (I get accused of to many engineering lectures as is), the 2.8 was a six and by design has a greater bearing surfacre area than the 3lt , effectively meaning that it is was easier to keep under control the health of an engines lifeblood ,its oil.

The fundamental issues above - were complicated by geniune second level issues such as why the oil quantity was increased , and oil splash to pistons increased etc in later variants.

Robin Miller

Nissan specifically advise against the use of fully synthetic oils in the ZD30 and any oil above CF specification.

Hi Blown4by

A reasonable statment that is and its good to get some understanding of why - although - I think you will find not a specific advice against its use but rather "It is not reccomended.

An unfortunate theme of many of the zd30 posts is that the complainent always had his vehicle serviced by Nissan - presumably using the right oil.

I'll leave my own comments out for now , and leave you a little note which appeared on a Patrol group website ,from an oil company in relation to this matter.
From it you may glean why my advice to the chap with the shell ultra should be ok but keep an eye of his oil level.

Robin Miller

----------------------------------------------------

It is claimed that CG4 oils leave combustion chamber deposits and it
is true that in some engines that are lightly run you can get bore glazing
with a CG4. The technology is also different in that CG4 type oils were
developed for a diesel pollution standard that requires excess soot to be taken
into the engine oil rather than being expelled into the atmosphere. They
generally can hold about 7% soot in suspension. The lower grades are
not designed like this and drop soot hopefully into the filter.

The Nissan engine is not designed to a CG4 standard and they
therefore have a CF4, CF rating for their oils.
Also keep in mind that low oil change intervals are specified.

You can run higher standards such as CG4 or CH4 but you should be
consistent. Once you use high grades, you should stay at that level
and not chop and change. During warranty you should stick to the Nissan spec.
Personally I like CF4 grades such as Diesel Formula or the J-Tech.

Regards
Jeff

Technical Department.
Valvoline Australia Pty Limited
www.valvoline.com.au

Robin if as you say "stress" is the problem with the ZD30 because it is too smaller engine for the patrol (I honestly can't understand your logic how a 2.8L TD engine is an ok size, but a 3.0L TD is too small).

You say that there is a greater bearing surface area on the 2.8. How have you calculated this? Surley the bearings would be smaller in a 6 of the same capacity as a 4 with the same capacity, hence surface areas would be no different. Have you got some evidence of such differences?

Are you trying to tell me that the only reason the ZD30 is "stressed" is not because of size but because it has two less cylinders?? Geez, that's stretching it IMO.

Yes I am aware of how peak kw and nm figures are not everything, but I still insist regardless of the peak measurements if you put a ZD30 and a Naturally Aspirated 4.2 and a 2.8TD on a dyno the ZD30 would bleep all over them. So why is it that it's more "stressed"? You didn't answer my question of where is this "stress". It's obviously not the bearings as I havn't heard anyone report anything abour bearing issues. Number 4 cylinder cracks and blown turbo's seem to be common faults on these. What has this got to do with bearing surface areas?? It's to do with poor oil lubrication (hence the upgraded dipstick, he hmm, sump.

It is obvious that there was a design fault with the way the oil is pumped through the ZD30 and the ammount of oil in stored in the sump as it is at the back of the motor where the problems occur and in the turbo (which is oil cooled). Explain to me how a turbo running at a standard 7psi is more stressed than any other turbo on any other vehicle running 7psi? Have you driven one? Do you know what they are like while driving them? They are not boosting all the time, they are not reving out all the time they are working and reving very little. My 3.0LTD in the surf (which is 11 years old) works a HELL of a lot harder and is stressed a HELL of a lot more than the ZD30, I know this as I used to drive both vehicles on the same stretch of road every day, several times in fact, and the ZD30 (even though I don't like it) rumbled along with very low revs where my 1KZTE was reving quite high and changing back gears in the auto gearbox up hills that the ZD30 sailed up.

Again, it does not add up.

Robin re ZD30DDTi see page 9-2 note 5 in GU4 Owners Manual Publication No. OM4E-OY61G1 quote "never use API CG-4". My understanding of "never" is that never means just that. Mate it is not a recommendation they are saying don't under any circumstances use it in that model engine. Whilst I have the highest respect for comments from reputable oil manufacturers I also reckon the Nissan product in my experience is a pretty good one that's why I entrusted them with 55K of my hard earned readies and since they designed the thing presumably with one or two of their qualified Engineers I reckon they are best qualified to advise what oil and change intervals are best for their engines. Until someone convinces me otherwise I will continue to change my own oil at 10k intervals as I have from day one using Mobil Synth 'S' 10W-40 CF grade semi-synthetic oil and genuine Nissan oil filters. The correct oil for the job takes into account a whole lot of factors not just it's detergency ability to hold contaminants in suspension until the next oil change and the additive package required to maintain acceptable wear levels . Such factors as sulphated ash content, valve seat and valve face materials, bearing materials, piston ring materials and many other factors and as such I reckon the guys that design it are best placed to decide what oil to use and how often. As I said elsewhere fully synthetic oil will probably do no harm but you will also probably be aware that most oil Companies, Mobil for one, recommend against using full synthetics for initial fill in the ZD30 and then for a run-in or better terminology would be "bedding-in" period before they are used.

Hi Jeff and Blown4by (I hope your title doesn't reflect a bad experience)

There's been a few good points and questions raised , if I miss anything please put it up to me again.

I accept that your GU4 manual may say "Never" my early stuff says "Not-recomended" either way its against Nissan's advice. I hope that the info provided shows in part why , and hence why synthetic's can be used - given not initialy.

I think the main thrust of your post Jeff , is why I say stress is higher in 3lt compared to smaller 2.8 etc.

I will try to put some clothes on my assertion.

The fundamental stress in an engine , is not so much compression ratios or boost
pressures , but is the pressure generated inside the combustion chamber at the point that the fuel ignites. This is directly where the stress is generated, and such stress is carried via the pistons etc thru to the crankshaft bearings, with oil in between over all surfaces including the piston walls.

Regardless of the peak power of any engine, the day in day out slog is much the same.
I.E. To keep a car is travelling along at say 100kph , it takes maybe 25kw.
It doesn't matter if it has 100 or 200kw, the vast majority of the time it just generates the 25kw.

So most of the time the 2 engines deliver the same power roughly.

To generate this power the 2.8lt has available to it 6 power impulses while the 3lt gives the same output but with only 4 power impulses.

Right here is where the stress is generated - one engine has less stress by a direct factor of 4/6 by inherent design.

Going further - The same 25kw delivers heat into the cylinder walls and pistons. In any system with the same enclosed volumne, if that volumne is spread over six cylinders instead of 4 then it requires a greater ratio of circumference to provide the same volumne.

Hence by design the 2.8 has an inherently greater surface area over which to hold its oil film.

This same logic follows thru to bearing performance, it is simply easier to maintain and control an even oil film pressure over 6 surfaces than 4, resulting in a more even heat distribution and hence less peak heat stress points.

The stress in the engine eventually finds the weakest chain in the link. Mostly it was pistons that gave up first in the 3lt . The initial reaction was to put in more oil and this helped, resulting in less failures, this was not enough, and over time a series of improvements , better oil paths, better oil splash,better materials, better control of turbo etc were introduced all the time slowly making it a better engine.

Robin Miller





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Yeah I do see where your comming from, however the cylinder's would be smaller in the 2.8 as there has to be two more of them for the same size of displacment, so therefore the cylinder's surface area in the 4cyl would be bigger per cylinder. Wouldn't this even out the difference?

But besides that, there are plenty of 4 cylinder motors putting our WAY more power than the ZD30, look at the new 2.9L Common rail in the Terrican for example. Are we expecting these motors to blow up at less than 100k too? I still think it is a poor design in oil flow/cooling, not an undersized motor. But hey, as you said, I guess we will have to disagree on this one.

And before we start on the weight difference between the Terracan and the Patrol, there are plenty of patrol's that have blown up without doing any towing etc, and I know that the Terracan is becomming popular choice for people towing large caravans and boats reguarly due to the cheap purchase price, 2500kg towing capacity and good amount of economical power output from the CR diesel.

So would I expect if I purchased a Terracan to tow a caravan around Oz for it to blow up at 80k because of stress?

Hi Jeff

Unfortunately whenever you have to enclose a bigger volumne you need
proportionaly less material to do it.
Taking a simple example if you make a box to hold 1 cubic cm , then it has 6 sides each 1cmX1cm for a total of 6sq cm surface.

Doubling the size to 2 cubic cm only requires the 4 sides to be lengthened making a total of 10 sq cm so to double volumne you need 10/6 or only 1.66 times the surface area not twice.

This is the basis of so many things - like a larger thermos will always outperform
a smaller one of the same basic construction type, or to make an atomic bomb,
3 little lumps of uranium will fizzle and crackle, but when rammed to together
the heat can't get out and so its goes bang.
(Maybe this not the best example I could have used)

Only way out is better design elsewhere , better materials etc.
Synthetic oil comes into this category.

Can't make any comment about the Terracan, I would see no reason why
it should not have a reasonable life.
Nissan had to have a combination of factors together to reduce the life of
the early engines such that sufficent went wrong to attract public attention.

These were average design of a small peaky engine, combined with the gearbox
ratios we have discussed and then pulling large load with a large rolling
resistance.

Guess this threads about done - catch you on another

Robin Miller

I was under the impression that full synthetic could be added to any engine oil (within reason - weight etc ) the synthetic oils are that good its like an additive to the cheap stuff.

I have seen some oil companies promote their product being able to be mixed, Mobil 1 does.

LMAO! As if a dealer would put two filters on it in an oil change just to "flush" it!

With the WA climate I would personally think that a 5w40 is not the best, however it will probally be ok during winter, just make sure it is changed before we hit the summer temps. I wouldn't really like to push my engine hard a long a soft beach at 40c+ temps with a 5w oil in it.

Then again, being a fully synthetic it's probally got a better viscosity stability at different temp's so it might be ok anyway.

You needn't worry about using a 5W weight oil in summer because a 5W-40 oil is a multigrade oil meaning it is designed to operate throughout the temperature range that 5W up to SAE 40 viscosity is capable of and these are covered in the Patrol owners handbook . In high summer temps in Aus you would need to go to a 5W-50. As regards not mixing brands that was true about 40 years ago but all brands of the same viscosity are required by law to meet certain SAE specifications and as such are capable of being mixed although I personally like most oil aware owners wouldn't do it unless absolutely necessary but if you can't get your favourite brand of oil at the back of Bullamacancka topping up with another brand of the same correct grade will do the engine no harm. Regards flushing the engine when changing brands/grades the amount left in the engine after draining the sump & changing the filter would be so insignificant it would not cause a problem. When oil Companies deliver bulk quantities of oil in their tankers they only drain them and do not flush them when filling the compartments with a different grade to the last that the compartment held.

Jeff,
what Nissan dealer do you work for? You sound like your speaking from experience? Filters are cheap when there your own brand (before tax), re-builds are expensive last time I checked. The original problems the ZD30 engine had were caused from the oil change interval being 10,000 km using the older type mineral based oil, carbon deposits=excessive heat. The newer oil is designed so that it lasts the 10,000 km between servicings, although given the problems of the ZD30 changing it every 5,000 km is what I do. Flushing the system properly, gives me piece of mind/assurance that I have done what is necessary to limit any future problems. I would rather do things properly now than post a winge later when things go wrong. But whatever rows your boat/frys your burger I suppose.

Oh sorry mate, I didn't realise I was supposed to work for a Nissan dealer to know that they are theiving mongrals...

I have had plenty of experience with Nissan dealers (I have had a few nissan in the past, and at the time had my eyes stapled shut and got them service by nissan dealers). I also have done a lot of work for car dealerships of Ford and Toyota and know exactly what is going on in these workshops full of apprentice mechanics and service managers working on commission to convince you that your brake pads are worn out when they aren't and that your air conidtioner needs "deoderising" (I'm sure we've all heard that one!).

Are you SERIOUSLY telling me that you honestly beleive that a Nissan dealer would pull your patrol into the workshop, drain the oil, change the filter, fill it back up, run it and then drain the oil AGAIN and change the filter AGAIN? LOL, mate it wouldn't happen, I don't give bleep what you think, it just wouldn't bloody happen.

Oh yeah, what's this new oil that's designed to be changed at 10k intervals?

LOL I here people say things like that all the time "Aaah with these new oils you don't need to change them as often" as they poor the same caltex gtx2 into the engine that they were using 20 years ago... Which brand of oil has been changed to allow for 10k intervals and how have they changed it? I'd honestly be interested to know this as it's somthing that never really seems to be explained.

Obviously synthetic oils can last longer in petrol engines, however in a diesel the oil is not just lubricating the engine, it is cleaning the contaminates out of the engine too, so how are they improving the oil exactly to hold more contaminates than oil we used 5 years ago?

I'll actually put my theory on extended service intervals here.

1. People are looking at service intervals and comparing them on new vehicles, so it has become a "feature" of a new vehicle that may give a manufacture a sales advantage over another competitor.

2. ULSD fuels are cleaner burning, reducing the ammount of carbon build up in the engine and allowing manufacture specs to stretch the service intervals out without having to change anything. (hence why a lot of vehicles that are being sold today that are EXACTLY the same as previous models have longer service intervals.

3. Possibly better oil filters that trap more contaminates than older filter designs.

I did a change on the 3.0 the other day and put in the Nissan 10-40w semi synthetic and I noticed also the next day when started cold how much quieter the engine is also.

Leroy

Chaz

Do you run the 5W - 50 Mobil 1 or that other 10w - 40 (i think thats the weight of the new stuff) ?

Brett

Hi Brett,
Up until now I have been using the 5W/50 Mobil1. I have the car serviced by the Nissan dealer every 40,000km and I do the 10,000km intervals with Mobil1.

Leroy, I do use Nissans oil occasionally, but there is a noticable difference with the synthetic.

Chaz