engine maintenance on 2009 GU crd

[harrymoto]

Hi all, I've just taken possession of Gu6 crd patrol and have read quite a bit about NADS etc. The engine looks in pretty good nic, no signs of oil on the intercooler ends and there's only a little oil around the turbo. I've cleaned the MAF sensor this morning which was not overly grubby but looked like it needed it and I swear it's running smoother and got more power - yea i know about placebo :). I'm not going jump straight into blocking the EGR or fitting mods but would like to fit some guages and clean the inlet manifold and anything else that is going to prevent the poor performance of the engine. I'd like to hear anyone's advice on what components I should clean or replace as a priority... and also if installing a catch can is necessarily a priority?
Its a 3.0l turbo zd30 which has done 130k.

[threedogs]

installing a catch can will hopefully keep your Maf a bit cleaner for longer.
First off I'd fit a boost and EGT gauge to monitor whats going on.
You'll be surprised what a dirty MAF will do so no not a placebo effect

[harrymoto]

Thanks mate yes have read all about the boost and EGT gauges and one thing I was wondering was that since the scan guage II can show manifold pressure which according to the website equates to boost pressure, would having one mean no need for a boost gauge?
Also is that all a catch can really does? ie. Keep the MAF cleaner for longer.

[megatexture]

If your going to the effort to clean the intake I would fit a catch can at the same time, if not its just going to build up again

[threedogs]

I have an ECU-Talk for my motor but I think the gauges show whats happening better

[the evil twin]

Thanks mate yes have read all about the boost and EGT gauges and one thing I was wondering was that since the scan guage II can show manifold pressure which according to the website equates to boost pressure, would having one mean no need for a boost gauge?
Also is that all a catch can really does? ie. Keep the MAF cleaner for longer.

If you run a Scangauge the only other gauge you require is EGT.

The scangauge shows the intercooler outlet plenum pressure in PSIA with the A being absolute pressure IE if atmospheric pressure is 14 PSI and the Turbo is boosting 16 PSI then the Scangauge will display 30 PSI (ambient pressure + turbo pressure = absolute pressure).
Your engine compresses abolute pressure X the compression ration to give you the cylinder pressure

A "normal" boost gauge works in PSIG and only displays the pressure difference across the Turbo so it will display 16 PSI
The issue is that atmospheric pressure varies from around a max of 15 ish to high 12's depending on altitude, temp and humidity.

You have several options
1. Get used to working in PSIA as that number is what you want to know anyway and is what determines overboost etc.
2. You can program the Scangauge to 'deduct' a constant number of say 14.7 from the absolute pressure and display the result but that is only accurate at that ambient pressure
3. Fit a 'normal' boost gauge but be aware that on high or low pressure days or at altitude IE in the alps etc it will be in error.

I highly recommend option 1 because;
If the Boost PSIA is say 25 PSI that means the cylinder pressure will be 500 PSI in a 20:1 compression engine, and
The numbers are constant IE you get used to seeing a similar number at cruise or boost limit etc

Options 2 or 3 mean that the cylinder pressure can vary be 460 to 520 for the same displayed boost figure (10 PSIG or so)

You would use 2 or 3 if all you want to know is the Turbo efficiency but it is the cylinder pressure that is critical to engine stress

[harrymoto]

Option 1 is the go for me thanks for that mate you're a dead set legend. For less than 200 bucks its a no brainer I reckon. Look for my post coming soon pleading for install advice :-P

[harrymoto]

So apart from gauges and an inlet manifold clean up would you recommend any other clean up jobs be done under the hood soon after 130000 ks? Can the turbo or intercooler be cleaned? if so is it necessary?

[harrymoto]

So I'm pretty sure I've got it now... basically I want to clean up the entire air intake system from the where the egr feeds crap back into the intake hose and then through the turbo and intercooler and last of all the manifold. I plan to give the sensors along the route a good clean up regularly as well. Im definitely going to then install a catch can (I'm dumbfounded why this would not be a factory fitting - I thought I just heard a Nissan executive manager in the corner over there muttering something about planned obsolescence). So then about an egr block but still some more to consider there that I might put into another thread.

[Beni C]

2008 CRD, first mods I bought were Scanguage, EGR block and Provent 200. Dont want those nasties clogging anything up!!

[the evil twin]

snip...
...I want to clean up the entire air intake system from the where the egr feeds crap back into the intake hose ....

...Im definitely going to then install a catch can (I'm dumbfounded why this would not be a factory fitting...


EGR
The EGR doesn't feed back into the intake hose it feeds into the inlet manifold via the EGR valve so blocking EGR won't do squat for the MAF sensor, Turbo etc.
The main reason for blocking EGR at the expense of pollution control is to reduce particulate contamination of the oil.
A very handy side effect is lower EGT's at low to mid throttle and low boost cruise and also improve power at low to mid throttle and general cruise,
EGR is normally blocked at high throttle/power by the EGR valve anyway so when you put the welly into it there is no difference.
The other big issue is that if you do block EGR you will need to either adjust your Turbo Actuator or fit manual boost control usually in the form of Dawes and Needle Valves and most engines will also get a check engine light and P0401 engine fault codes.
Easily fixed by a Scangauge or drilling the EGR plate but that defeats the purpose of blocking it IMHO

Catch Can
In fairness to Mr Nissan, AFAIK there isn't a diesel engine LV sold in Oz by any manufacturer that has a catch can as a factory fitting. There may be some but certainly none I have come across.
Modern high pressure diesels are now at a stage that a catch can usually isn't warranted however older stuff certainly is a different issue (6.5 Chev for example).
The CRD's seem to vary between engine as to how much oil mist they blow past.
I was lucky in that mine did very little so it didn't warrant a catch can, others have reported noticeable amounts.