My Engine Has Issue But Cant Quite Put Finger On It

[luthepa1]

Hey All,

Need some help and advice. My car has been blowing a little smoke since a recent repair and I am not sure what to tackle next in trying to identify and resolve. Today it was noticeably worse for some reason which helps in trying to better understand the issue. It has been hard to replicate as its been quite intermittent except for travelling to work in the morning there seems to be a scenario that seems to be able replicate. That is I let it coast on its own momentum downhill before entering the Sydney tunnel and just as I enter the tunnel I apply a tiny bit of throttle (500rpm) to pickup momentum and see a puff of smoke come out. But usually after that I dont see anymore smoke (as if it clears itself). However when I pull up to a stand still at lights or whatever I can smell it.

One other scenario where I can reproduce the smoke was joining the motorway I boosted it through rev range and max boost and immediately after backing off throttle smoke!!! But that I have only managed to see once.

The other thing I can do is when I come back from a drive and park my car I will rev it high and then when the rpm comes back down to idle some smoke comes out. See this link for vid https://www.dropbox.com/s/278rebeaeejjxud/VID_20130405_213304-trimmed.mov. However this will not happen on first start, cold start. Cold start is all fine and not reproducible. Also on a cold start I find the vacuum seems to be a little high than when its really warmed up. For example on cold start it might be -8psi and when really warm (bit of a flex) it will most likely be -10psi. -10psi is what it use to be before new legalis R exhaust though.

Today however it was a lot more reproducible multiple times to and from work. It seems to be more along the lines of you're cruising along, then back off and coast/roll and then when you apply throttle again it blows smoke - white smoke. Valve stem seals perhaps? I had been a little worried about the turbo as the exhaust took a brutal beating from a accident the wife had by which she ripped the whole exhaust off from catching a speed hump in a shopping mall car park. Managed to ripped the dump that Scotty makes up.

Quick History:

- Week before Xmas blew turbo in summer heat (was stock crap)

- New sierra stage 1 hi flow turbo replacement with new dump by scotty but still be stock exhaust (getting 17-19psi boost)

- First week Feb 2013 exhaust incident (clean break at cat of front pipe and dump pushed up and ripped). Limped it back home (So loud!)

- Ordered new legalis R exhaust and finally fitted 3 weeks ago tomorrow with a 2nd dump and decat front pipe by scotty.

- Noticed smoke as soon as leaving with new parts. Car was hitting 22psi and error code 235 present on ECU. Bypassed cars stock bleeder and now maxes out at 17psi across whole rev range. No new error codes on ECU.

- Not always reproducable (before today at least). Went for a slow family cruise last sunday and never blew any smoke. Day before on Saturday saw some smoke when I gunned it! See attached log graph.

Suggested to date

- Turbo rear seal

- PVC

- valve stem seals

Any help/advice greatly appreciated.

[scotty nm35]

White smoke is usually coolant I think, are you sure it's white? No blue tinge?

The oil seal in the rear of the turbo can leak sometimes, especially if the drain is partially blocked. I wonder if anything further on the turbo was damaged? That dump took a hard hit...

The only other thing I could think of is you cracked a ringland when the boost spiked, did it knock? I would guess a Sierra stage 1 has more than enough puff to max the injectors. You could try a compression test.

[luthepa1]

It could be a blue tinge but I not really sure. I can only go by what I see in review mirror and I have not had a car that blows smoke before to tell the difference of white vs bluish. I might need to get someone like Craig to take a look for his expert advice. However I suspect it would be from oil burn therefore blue as oil level going from max down to half or even 1/3rd seems excessive for 500kms? I'll check the the radiator overflow bottle tomorrow although engine temp is constant at 1 notch below half way all the time.

Your right the dump took a hard hit so nothing would surprise me if turbo has damage.

I have not noticed any knock and have not seen any error code which i thought would be detected by car ECU? When I first left workshop after new dump, front pipe and exhaust fitted I never fully gave it stick. Drove hesitantly with 2/3rds throttle max because I noticed smoke. The following day went for drive again and started to push it and that is when I would have got that error 235 as fully boosting it uphill if felt and heard the engine retard as it pulled back the timing. Saw the boost instantly drop from 21psi to 17psi and was like that until switching car off to reset.

Think your right though.. a compression test is in order.

[Jezboosted]

I can only help by possibly eliminating valve stem seals. Generally this issue shows up most on cold start as oil has had time to run down valves, past stem seals into chamber.

[scotty nm35]

Same with the PCV, they usually dump oil into your plenum overnight causing a puff of smoke on first takeoff. If it failed though, it may cause much more issues.

What oil did you put in it Paul?

[m35stagea]

Sounds like valve stem seals to me.

If you let it idle for a period of time will it start to smoke?

Or smoke if you idle for a while then accelerate?

[luthepa1]

Same with the PCV, they usually dump oil into your plenum overnight causing a puff of smoke on first takeoff. If it failed though, it may cause much more issues.

What oil did you put in it Paul?

I just took the PCV out to have a look. It seemed fine but then I wouldn't know what a rooted one would be like. It has a quite rattle shaking it except side to side not really. It looked very clean and I could see the internal parts move freely turning upside and so forth.

Put in Motul 300v Chrono 10w40 in it. Craig and I just dump the whole bottle in so 500mL overfill but that be long burnt off by now.

Sounds like valve stem seals to me.

If you let it idle for a period of time will it start to smoke?

Or smoke if you idle for a while then accelerate?

Well on a cold start I let it sit and idle for a few minutes for engine to warm up. But I never see or smell anything when I drive off. Also when I am in bumper to bumper peak traffic I dont notice anything either. Its only after engine or turbo have mid to full range use I'd say. And the most replaceable scenario is the drive to customer for work in mornings where I its bumper to bumper traffic until join motor way, then up to half throttle half boost (~14psi) and drive for 3-5kms I think then the downhill roll, then apply 500rpm throttle and then the puff of smoke. After yesterday I was a little pissed so too it for thrash last night. Did not see any smoke but could smell something strong when pull up at lights. Then just now after removing PCV to clean, when for quick boost. Again I can smell something but not see anything in review mirror. So today car more like it has been. Dont know what was up with yesterday.

Got some pics though of intake pipe before throttle body. What you think guys?

[scotty nm35]

The piping will always have oil though it, as the breather goes back to the intake. (Unless you install a catch can)

Usually if you can smell burning oil it is coming from the passenger rocker gasket leaking, as it drops down onto the turbo housing, then gets sucked into the heater fan.

[luthepa1]

Pics of intake pipe.

https://www.dropbox.com/sh/i462ttikrnickzz/X-QIlYaDTz

[scotty nm35]

If you think that may be the source, wash all the piping and cooler out with kero and let it drip dry.

[luthepa1]

The piping will always have oil though it, as the breather goes back to the intake. (Unless you install a catch can)

Usually if you can smell burning oil it is coming from the passenger rocker gasket leaking, as it drops down onto the turbo housing, then gets sucked into the heater fan.

Ah! that's a very interesting bit of info! I say that because the other day I was driving with all windows up (usually down as aircon condensor got a hole and no gas) and I swear I could smell it inside the car. Then I saw the smoke in review mirror.

[KiwiRS4T]

Do a compression test. Eliminate or not that problem!

[PN-Mad]

Yup, comp test ASAP. The oil got there somehow, and I hope that somehow is from turbo seal, not excess crankcase pressure. That would be from cracked ring lands, or pistons. Having a big over boost doesn't do it any favours.

As Scotty said, you'll need to clean the whole intake out, and flush with kero including the fmic. That way you can see if it comes back.

[luthepa1]

Cheers guys! Now I got a plan of attack!

[luthepa1]

So I managed to get round to performing compression test yesterday. In doing so I discover at least 1 issue which is the rocker cover gasket needs replacing as I found oil in some of the spark plug chambers. Sparky closest to turbo on passenger side had so much I could not see the spark plug until syringing it out. Middle passenger was dry and front passenger had oil to half cover sparky. On drivers side all dry except the middle one which had a tiny bit of oil but I could still see all sparky down to the hex part of body. Interestingly though this drivers middle cylinder had the highest compression. Note: The compression test tool I had was one where I had to hold it against the spark plug port while someone else cranks the engine over as opposed to having a screw in type. So perhaps allow for some variance I am thinking. I pulled 2 10A fuses during the test that I believe would disable the fuel pump and IGN (The left most top & bottom of fuse box). Not sure what the optimal psi should be for each cylinder?

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

What you think? Visually looking as best I could front top side I can not see any oil leaks externally anywhere. The turbo looks dry. I also took a look at PCV again. Clean and free moving inside. Rattles slightly but not side to side shaking. Blow in one end occludes the other end free and open. Other thing I did notice was where the original black tubing from turbo joins the first elbow pipe to FMIC entry in front of passenger wheel looks a little damp at hose clamp. So suspect the oil inside here. Below is link to some shared pics and vids of my finding (plus some other pics of not interest probably).

https://www.dropbox.com/sh/dhrb64qrxsuuit5/DHN4tPsDGU

Edited April 14, 2013 by luthepa1

[scotty nm35]

Oil in the plug tubes is a common VQ issue, replacing the rocker gasket won't fix it as the gasket only goes around the edge of the cover. Those seals around the plug tube are moulded into the cover and can't be replaced. You would have to buy a new cover to fix it properly (~$250) or simply seal it with a little silicone sealant if you can.

The compression test results would be skewed by the oil dropping into the cylinder, at a guess it looks fine as we have low compression engines, 120psi dry would be about right.

Have you thoroughly cleaned the cooler and piping?

[luthepa1]

Yes I agree I think some oil dripped in especially for the cylinder that got 140psi. So that said then I can assume the ringlands are good?

Have not got round to cleaning the FMIC yet. Work been pushing me to the grind (11hrs days not including travel - leave not personal time). Plus trying to figure out how and where to flush. Can I do the flush in a big pan/drop bucket? How much cleaning fluid would I need? I got the HDi cooler.

[scotty nm35]

Some pressure pack degreasers for the pipes, and a few litres of kero to swish around inside the cooler would do the job. Take note of how much oil there is in there, if it isn't much you have other problems.

[Commsman]

Re the compression test, when I did mine all had 140psi (different gauges may get different results) except one which had 100psi. Was pretty obvious if was busted.

Your results show similar pressures across all cylinders, so you could be OK in that regard.

[luthepa1]

Ok so I took the FMIC and piping off today and kero cleaned. There was oil but I not sure if its out of the norm. Below is link to some pics I took. The intake side was relatively clean but with some oil traces around the blue hose join. The output side did not seem to bad either except it did have a little pool of oil sitting inside. You will know from the pics. After washing I poured the used kero back into bottles which looked like coke a cola in the end. Looks worse than it is I think. But again I will let some experienced people provide feedback for your thoughts. The black original piping from the turbo to the HDi elbow bend did not look to have fresh, wet oil. I have not gone for a drive yet but will report back when I do if still seeing smoke.

I was also playing a little more with the PCV valve and wanted to verify if these things seem correct. I tried removing the PCV hose from the plenium and in 10sec roughly the car stalls. Then trying to blow into the hose attached to the PCV it was occluded (car off).

https://www.dropbox.com/sh/f30el295h2nr1bm/6BRNtMjIen