Another Exhaust Smoking Problem

[shuedaman]

After reading previous posts about smoking exhausts i've completed a test drive and a compression test (128, 145, 135, 141). There was quite a bit of oil on valve cover and car smokes when accelerator is smashed and for a few seconds after, but not on start up or at idle. Problem started happening right after i just finished installing new mods: supra sidemount, MBC, Upper IC pipe. Car has power, holds 14psi fine, no issues except the smoke. i have driven it VERY little because of the smoking, so i can't tell if the oil has become brown and i don't yet see any oil in coolant. Also, i do NOT know if the smoke is blue or white, too hard to tell. Any suggestions on next diagnosis step or what the problem is? Any help would be much appreciated!

 

[Eastwood95]

is the smoke coming from the engine bay or exhaust? I would start with a boost leak test........it could also be the turbo from those symptoms. Is it whining?

 

[shuedaman]

Smoke is only coming from the exhaust, it used to whine the first time i spooled it up each time i got in the car, but it has done that since the new mods. Does it make sense to have oil on the valve cover if it's the turbo? i will do a boost leak test as soon as i can.

 

[Eastwood95]

hmmm, dumb question but did you do an oil change lately? spill any around the filler hole? You can also check the oil filler cap, sometimes the gasket leaks oil into the valve cover. Another thing to check, the oil dipstick........could be blowing oil out of the dipstick. Check the underside of the hood for oil spots when you lift it. Those are pretty obvious things to check, i'm not trying to call you an idiot, i'm just thinking of things to check so bear with me. I dont think the oil in the valve cover would have anything to do with the exhaust smoke though. So your turbo did whine and doesnt anymore? Did you check the turbo for shaftplay? Check those things out and do a boost leak test man.......let us know....

 

[MrBoxx]

Check the turbo for shaft play. (It's been a while since I've said that. ) Especially if the smoke is whitish-gray, it's possible that the turbo's seals and bearings are shot, which leaks oil into the lower intercooler pipe and gets into the engine. Don't ask me why it burns whitish and not blue like oil is supposed to; I just know that in the case of a blown turbo, the smoke is white. Recently I read another post on here, possibly by a wiseman, that to truly rule out shaft play in the turbo, it's a good idea to check the hot side and see if there's play on the turbine side, but that's a little more involved than checking it from the intake side.

For the review: Take off the intake pipe/hose, stick your fingers in the compressor inlet and grab the nut of the compressor wheel (I don't have to tell you to do this with the engine off and cold, do I? ). Try to wiggle it up and down, side to side, and in and out. Any in and out play will most likely mean you need a new turbo. Very little side to side play is allowable, but if the blades touch the compressor housing (which can cause the whining noise Eastwood95 mentioned, and can also make a scraping noise when the car is turned off as the wheel spins down) then the turbo definitely needs replacing. To verify seals going bad, remove the lower intercooler pipe/hose and look for oil; a coating of oil on the inside of the intercooler pipe is okay since it probably came from the valve cover hose, but a pool of oil at the bottom of the hose or in the intercooler is definitely indicative of turbo failure.

But, for posterity's sake, do a boost leak test.

 

[shuedaman]

Been waiting for rain to stop so that i can do boost leak test, but in the mean time i noticed that my PCV breather hose was NOT placed back on the intake pipe after the last install (friends can be SO helpful...). I JUST put it back on, haven't driven it yet, could this have been the problem? I have had a leaky oil cap before, the rather large amount of oil that was there isn't from a leaky cap i would think. Did an oil change about 500 miles ago, didn't spill oil (i.e. cover was clean before latest mods installed). I still have to see if it's the dipstick. Considering i just cleaned and replaced most of my intake track last weekend it will be easy to find out if any oil has crept into the lower hose when i get a chance to lift it. Will post more when tests are done, any ideas still welcome!

 

[shuedaman]

Alright, Turbo still seems to have ZERO shaft play, turbo seemed in great condition (no shaft play) when i bought the car so i'm not surprised. Boost leak test showed 1 leak: Supra smic is leaking because of flipped end tank, i'll fix that tomorrow and post another update. The oil on the valve cover is definitely form a leaky oil cap, although it is leaking an awful lot of oil, i've been cleaning a lot... I turned the boost down to 10 psi from 13 and car has stopped smoking entirely it seems. Another thing i though of: there was left over gas in the intercooler from when i cleaned it, i idled car for a long time before i actually drove it but maybe all of that gas was not burned out yet? I think that's it for now...

 

[toybreaker]

Might want to clean the pcv valve.

It's on the valve cover, at the rear.

Remove it to clean

Spray it out with carb cleaner. test it by blowing thru it, (by mouth)

Correctly operating and clean, you can't blow thru it one way, but the other way you can, but with some resistance.

Deposits in the pcv can cause it to stick, creating excess crankcase pressure/oil leaks/smoking.

 

[shuedaman]

I'll clean PCV valve as soon as i can. With boost leak fixed the MBC works much better! There was no oil in the lower intake hose and the turbo whines on very rare occasions, seems to depend on what day of the week it is. Thanks for the help so far, although i would like to know what made my car smoke in the first place even though it seems to have stopped now.

 

[Eastwood95]

your car might have been smoking just from the boost leak itself. If you have a boost leak, it causes the car to run rich, which will throw black smoke from the muffler/exhaust. Most of the time when you find and fix a boost leak, it will stop the car from running rich, and clear up any smoke from the exhaust. Fixing that, in addition to confirming the turbo had no shaftplay, sounds like it cleared up the problem. Now you just need a new oil filler cap that doesnt leak....

 

[shuedaman]

Seeing as how i've already gone through 2 oil filler caps, anybody have any preferences toward aftermarket/non-mitsu caps? Thanks for the help!

 

[shuedaman]

UPDATE: car is smoking again... Smoked like crazy just idling in drive way, drove a few miles, smoking stopped. Check engine light is now on. Also, car now feels gutless, like i have a major boost leak. I will do another boost leak test tomorrow, check the check engine light, and look into the exhaust because i can smell exhaust very easily under the engine bay and i think i have a leak in it. Fun times, anyone with ideas please help, THANKS.

 

[oldman]

You have one cylinder below and one near the sevice limit, the other two are far from being perfect. You need to go back and double check your compression test results and follow it up with a wet test, or you can just skip ahead to a leakdown test.

 

[shuedaman]

alright, another compression test was done (correctly this time...) and all the numbers were within 5psi and around 190. when i fixed the intercooler leak, one of the hose clamps was not tightened down correctly, and now that it has been fixed i will go for test drive, although car is still smoking from exhaust in driveway and i can still smell an exhaust leak. If i get the chance sometime soon i will do a leak down test, another boost leak test, and fix that check engine light. Keep the ideas coming, thanks!

 

[shuedaman]

Check engine light codes were for improper a/f ratio, and random cylinder misfire. Did i change something by upgrading the intercooler that i didn't think of that may have screwed up the a/f metering? Any thoughts?

 

[shuedaman]

i don't know if anyone has any other ideas, but i am rebuilding the turbo now and hopefully will be operational again by this weekend. still wondering why ecu claims a/f ratio is incorrect.

 

[Eastwood95]

hey, maybe you have a bad o2 sensor..........also, before you put on the supra sidemount, did you clean the inside of it? Did you check it for leaks? I'm sure if there's a leak, you should find it with the boost leak test, but i was thinking maybe it was leaking around the plastic endcap that you had to reverse........

When i had my supra sidemount, i filled the damn thing with water before i installed it and found a small leak....

 

[shuedaman]

I was actually thinking exactly the same thing, how would i know which O2 sensor is bad though? where can i get one cheap? Supra sidemount is VERY clean and I did find a leak in it that was fixed after the first boost leak test. I did another boost leak test and did not find any leaks. Rebuilt turbo boosts good, set at 13 psi. Still smokes some at lower RPM's, although there seems to be a large reduction in the amount of white smoke. Maybe several things are going bad, i do have 135000 miles on it... Still more white smoke occasionally though, so i am still looking for answers, i'm thinking O2 sensor(s) and injector cleaning next... Thoughts?

 

[shuedaman]

Alternator seems to be dead so i am having that rebuilt and when i can get that back in and working i'll get around to working on exhaust smoking problem.

 

[shuedaman]

been driving it around quite a bit since alternator was replaced. Smoke seems to have disappeared again... Check engine light is still on but car seems to run fine other than that, so unless anyone has any more ideas i'm going to drive it more often and get ready for 16g upgrade.