My Engine Has Issue But Cant Quite Put Finger On It

[luthepa1]

Ok so went for a drive and things seems worse - or more replicable now. First thing I noticed was that the turbo makes this kind of metallic scratching noise I would describe it as and was something I noticed since day 1 of this new turbo. A thicker oil (10w40) that I now run seemed to quiten it down until now. When you accelerate you will start to hear the turbo make its spooling noise which sounds ok but then when it starts making positive boost or gets to about 2600rpm it starts to make a slightly more metallic sound.

The next thing I noticed was smoke. More of it today. Seem to be able to replicate it 100% when decelerating downhill. Key point there is downhill and deceleration. On one occasion I had to stop on a downhill at traffic lights. When they went green and I drove off I did not see smoke. So seems you need to have some speed with equation. But also I noticed in the residential zone I lock it down into 2nd gear and give it some stick and then there is smoke too!

Also another strange thing I noticed today was when I accelerate to see how the boost goes, it would drop back gears like usual, hit 17psi like usual but then seemed to want to kick down another gear (or felt like that was what it was doing) and dropped to 14psi but then building up again. That seemed strange as usually my car will hold 17psi through whole rev range and whole acceleration. Something funny going on there (fuel pump/injectors?).

So I am really thinking now my turbo is failing. Is what I just describe back that theory up?

NOTE: On cold start there is no smoke until the engine comes up to operating temp. Just runs rich.

[scotty nm35]

It certainly doesn't sound good. I assume the oil banjo was drilled? What turbo is it again? And is it a bushed core?

[luthepa1]

It was a sierra stage 1 turbo hi flowed. As for the other 2 questions I would have to ask Craig.

So I should probably stop driving my car until I can get turbo repaired, right?

[luthepa1]

So this morning on drive to work I managed to keep completely off boost (Max 0psi) which is hard and I did not see any smoke except for little bit on the usual down hill part before entering Sydney tunnel. So it does seam like turbo.

What i never thought to pick up on is the smoke occurs when car is at Max vacuum which in this case is -13psi. At stand still when engine warned up it is -10 to -9psi. On cold start it's -8 since new exhaust.

So if turbo is the issue then does low vacuum make sense? Is it because the seals can't cope? I'm just trying to make sense of it.

[Commsman]

Sounds a lot like mine was (is) Paul. Mine always smoked on throttle lift after a boost event, so max vacuum.

Try temporarily disconnecting the PVC hose to the plenum (plug up the hose going to the plenum) & go for a drive & then let us know results.

[luthepa1]

So you mean with the house still connected to plenum plug that hose and the PVC would be disconnected from that end of hose (atmosphere).

So basically plugging the plenum? Because I tried taking PVC house off at plenum and car will stall which makes sense add there is air intake bypassing AFM.

Sorry if my question seems a little stupid. Just want to be sure ;-)

[Commsman]

Yes, exactly right. With the plenum hose going to atmosphere you will have an issue with air metering (stalling), as you have experienced. Plug it up though, & the car should function OK. There may be a little oily gas vapour coming out of the open PVC, but that will be OK for a brief test.

[luthepa1]

So I removed the PCV hose from plenum but no joy. Car still blows smoke. Traffic was worse today and my usual downhill roll into Sydney tunnel was absolute crawl and so did not blow smoke there today. Seems I need that magic number of -13psi for a handful of seconds or I need to boost hard to make turbo work and then there will be smoke.

[luthepa1]

Hey Guys, Im back! Been just over 4 months now since last post but in short I still have this issue of my car blowing smoke. Pretty much the same situation as written in my first post #1. To sum it up

1) Coasting downhill with no throttle applied >= 80km/h, achieving max vacuum then apply any amount of throttle will present smoke that clears in 3 - 10sec.

2) Zippy driving - when driving though residential back streets with lots of start stopping I will lock it in to manual mode using only 1st and 2nd gears to get quick response time from this lethargic gear box. Not speeding just keeping motion. I watched the RPM and noticed I am always in the 3000 to 5000rpm range. This style of driving almost guarantees smoke on back off.

Since last post in April the turbo has been taken off and rebuilt. I noticed before rebuild that oil was building up in the intake piping and FMIC. I am happy to say after turbo rebuild just over a month ago now that the intake piping has stayed spotless! Just like it was after kero cleaning. However on rebuild invoice it was written that turbo was heavily contaminated and if my root cause was not fixed I will void warranty. I've also noticed since the rebuilt turbo was fitted the smoke blowing is not as bad but seems to slowing be increasing again.

Also since rebuilt turbo I have replaced the PCV valve even though I am certain the original is fine. I have cleaned the K&N filter with recharge kit as it was filthy. And this weekend I have replaced the spark plugs which the originals look like crap. See pic here which prob sums it up.

The other thing I noticed which is alarming is that my oil is on the empty mark of dip stick!!!! Thats a loss of 800mL minimum since rebuild. With overfill more like 1L oil consumption! And I have only done approx 893Kms in that time. That's bad.

I also found this good read from this turbo repair guy in Melbourne. Very interesting read. What I took from it was that turbos are not reliability issue module but rather an easy victim. http://www.procharge.com.au/turbotorque/6-blog/blog/117-the-turbo-blues

One interesting troubleshooting step was gear box on an RB being the cause. Can anyone elaborate on how this could be? My gear box has not been its absolute best for some time. Generally its ok but sometimes it has a bit of a shudder because its trying to stay in 5th gear in 60km/h zone at 1700 rpm or even less. So it starts to drop to 4th then decide no 5th is the gear to be in. Sometimes I will knock it into manual mode to prevent 5th gear. This does not happen often. Usually only after a motorway drive like 100km/h then coming back to residential speeds.

Then lastly tonight I plugged laptop into ECU to check for faults and found a few.

P1320 - I removed ignition fuse for injectors as I did a compression test during spark plug change. Not concerned here.

P0235 - I have the boost solenoid disconnected as I don't use it so to keep turbo boost down to a max of 17psi. After fitting new legalis exhaust and the stage 1 hi-flow sierra turbo it was hitting 21psi and one day the engine retarded hard.

Then I saw this from gear box TCM module

P1772 - Low Coast Brake Solenoid Valve

I'm worried a bit hear but I keep wondering how and if the gearbox could have any kind of impact on my smoke blowing situation although I know its probably wishful thinking. First thing tomorrow I will double check the trans fluid level but believe it was ok last time I checked. Is there more than one place to check?

Oh last thing. On cold start to initial warm up there will be no smoke issues. Its only when the car is fully and complete warmed up.

And compression test results. First numbers are from 4 months ago and second numbers is yesterday results. Nothing really changed here.

Front of Engine

2) 120psi / half oil 1) 125psi / no oil

4) 120psi / no oil 3) 140psi / tinniest bit of oil

6) 130psi / lots of oil 5) 125psi / no oil

Front of Engine

2) 120psi / no oil 1) 130psi / no oil

4) 125psi / no oil 3) 140psi / no oil

6) 120psi / tiny bit of oil 5) 135psi / no oil

Link to pics of spark plugs.

https://www.dropbox.com/sh/aotyfpjhiuuqcwu/IV3aRbmyMC

Ok I'll stop yapping now. Could probably go on forever. My car issues all start the week before Xmas last year and still going. I am tired.

Paul.

[scotty nm35]

If it is still blowing smoke you may have to drop the intake/dump and check the shaft play. Unfortunately I have seen this a few times with highflowed bush cores and on the M35 there just isn't enough oil flow to allow bush cored turbo's to last a long life. The turbo builder was right to be worried, but he sells bush core rebuilds to suit our Stagea without knowing the low oil flow/high oil pressure design of our engines.

There are 3 x 0.9mm oil restrictors in the oil feed before the turbo, if any one of them gets blocked, even partially, the turbo will fail quickly. If you don't rectify the blockage the next turbo will fail also. I now drill these banjo restrictors out to 2.5mm to make sure oil supply is increased and the chance of a blockage is reduced significantly.

If you drop the banjo bolt on the block and check the oil flow you will be surprised how little oil dribbles out, even after drilling the sump banjo bolts.

[luthepa1]

Really. So all my probs could still be to do with oil restriction. I know when Craig fitted the rebuilt turbo he fitted a 2.5mm sized banjo but i was under the assumption there was only 1 restrictor not 3. Got some home work to do then. Need to figure out where these restrictors are as not familiar with this area of engine. Only starting to get familiar with top end now that I got workable conditions at my new house.

I am a bit concern at the moment because on my drive home just now I hear the normal high pitched air guzzling sounds but then after 3000rpm i hear an additional noise that kind of sounding like a quite maybe siren noise. That I dont want to hear. Or could be just a healthy noise. I just associate siren noises to not be good noise. But more driving prob needed to confirm this noise really is there all the time.

[luthepa1]

Well time to bring this post back to life again.

The final 2 out of 3 banjo have been drilled out larger but my problem still continues. I have travel 1500km and lost at least 700mL oil. I'm practically on the low mark of dip stick now. Note: if I remember correctly the 1st of 3 banjo was returned to original size in last turbo rebuild.

So now I wonder if my turbo is really the issue. Now thinking engine (valve stem seals). I mean... Can a turbo be in a state where it keeps consuming oil but drive fine? My car runs good. No issues and no error codes from ECM or TCM. car drives awesome but on a downhill deceleration above 80km it will blow smoke in reapplying throttle briefly. Or if I lock trans in manual and keep revs greater than 3500rpm it will blow smoke when reapply throttle.

How much to repair valve stem seals?

If ripping the head off should I get lower end rebuilt? How much that set me back?

Get a new engine if that's even possible to find? $?

Just trying to review my options here. I have got to point I thinking of getting rid of it.

Cheers.

[gleeson]

Mine did the same thing and the turbo was gone,this will be spilling oil into your exhaust causing it to smoke.I would be taking scotty's advice and checking for shaft play in the turbo.i did less than 50 km with my new highflow when it shat itself.Stupid f**king restrictors

[luthepa1]

Mine did the same thing and the turbo was gone,this will be spilling oil into your exhaust causing it to smoke.I would be taking scotty's advice and checking for shaft play in the turbo.i did less than 50 km with my new highflow when it shat itself.Stupid f**king restrictors

Really. Its frustrating as I have had the turbo rebuilt twice.

[luthepa1]

Thought I might stir this post up again. Its been almost a year and same situation but I thought that might be interesting in it self.

I have installed catch can between crank and air intake before turbo but I am not seeing it fill at all. Intake piping before FMIC looks reasonably clean, nothing like when I did have a leaky turbo. And the dump pipe is also reasonably clean was the feedback from the pics I originally posted a while back. Oil consumption is about the same at 800mL every 2500kms, no matter the thickness (e.g have used 10w60, 10w40).

Scotty: Just over a year ago on post #30 you mentioned concerns of turbo with bush core and lack of oil flow. But considering a year has gone by and car and turbo still perform well would you still suspect faulty turbo?

I posted link to the dump pics again for a FYI. Although while I find the intake piping clean enough inside what are the thoughts of pic 14 out of 14 in the link of elbow from turbo to FMIC? Externally it gets oily/dirty all the time. The hose clamps are tight.

https://www.dropbox.com/sh/na59gf9f8ccalpb/AAC9Ckkn-CbWZd0EeEan4_iDa?dl=0

[coparts41]

Is it a roller bearing turbo , if yes it could be a problem with oil flow to the turbo . Just finished my sons r31 gtsr with a rb26 running on E85 , had to change the Injectors , rail and fuel pump but ended up with 535Hp at the wheels , however the turbo was still smokey (brand new turbo) on the dyno and we had to install a restrictor into the oil delivery line as the turbo cannot handle the pressure or quantity of oil and leaks through the rear seal.

Now this engine is running 20 PSI boost and will run 24psi quite comfortably when we change coil packs , Not saying this is the problem but something to look at.

[scotty nm35]

The hypergear highflow turbo's need 10 times the oil flow of a ball bearing core. I have seen many fail, usually very quickly, unless the restrictors are drilled out.

My old ATP highflow didn't require so much flow, in fact it ran fine for years without drilling the sump banjo's, mainly because I didn't know about them then.

Most likely the turbo seal at the turbine side is not sealing properly, but it could well be in the engine. Which path do you want to take for rectifying the oil burning? Personally I would be getting the turbo seals replaced first, as that is the cheapest option. Mine goes through a similar amount of oil so I wouldn't be worried about it too much, but I don't see any oil smoke in my car.

One thing to try is to put a catch can on the PCV temporarily, to see if it has failed or is letting oil into the plenum.

[luthepa1]

Cheers guys! Well maybe I should try getting the turbo seals replaced if its a relatively cheap thing to do (compared to pulling head off engine). Process of elimination.

Yes I was just speaking to my Bro of putting a catch can on the PVC but I need to find something smaller than all these 400mL+ catch cans you see on ebay. There's just not enough room in these M35's. Any recommendations?

[djr81]

TL DR. Valve stem seals.

[scotty nm35]

If it were an RB i would probably agree, but I am yet to see any VQ's with valve stem issues, even with 300,000 ks. There is always the chance this is the first.

Highflow turbo's though... Very common.