In detail smoking issue.

[HRCEngineering]

Hey all. I posted my situation in the improper forum so here goes again. Hopefully the mods don't get upset; I'm sorry for posting in the wrong forum. Anyways..

For the past few months I have been burning oil. On start up it usually puffs a decent size cloud. It tends to only burn at idle and a tad on take offs. From what I know about engines, it could be a bad turbo bearing seal, PCV valve, valve stem seals, or the rings.
As for my car in particular, I have all the supporting mods for my choice of boost pressure, super 16g, street fmic, 190, turbo back, port work and so forth. Compression is 178 across all four. Car is a 95 GST with 40k miles on it.
I have pressure tested my car numerous times, and tend to test it twice weekly. However, I have not listened in the oil cap of the head to hear if the seals are possibly bad. I had originally thought valve stem seals as the car is ten years old and sat for 30 months in a old guys garage. However, he had the head rebuilt at 29k miles.
This afternoon I removed the intake pipe to check for front/back turbo shaft play on the intake side of the turbo. shaft play was at a minimal noticable amount. What did catch my attention, however, was that there was a SMALL amount of clean oil on the turbo inlet. there was also some older(?) oil residue on the inside of the connecting end of the intake pipe. I am now leaning towards a bad seal within the turbocharger.
For the amount of money I had planned to spend to pull the head, I figure It'd be a lot more practical to send this turbo back to Hahns and have them upgrade it to their 20G to the tune of $400USD. What do many of you tend to think of their 20G from PERSONAL experience, not bias?
Lastly, would most of you agree that this sounds like a case of a bad turbo seal? Thanks for reading about my woes, and thanks for any help whatsoever.

-Ray

 

[silver eclipse]

Same symptoms happend to my car. It was the turbo seels on my t25. Learning through my expirience I would stop driving the car, it will only get worse until you have the trubo rebuilt. Its desiving by only puffing at crank and a lil at the go, but if its the turbo it will starts smoking all the time till it burns up the trubo. My t25 is pretty unrepairable do to shaft play and what not.
-Chad

 

[HRCEngineering]

Thanks for the reply. I have almost no shaft play front to back as I said. I also tried to push it in an inward/outward motion. My girlfriend watched me drive down the Blvd. and said it seemed to smoke continuously, contrary to what I thought. Could it have started a while back at only idle and take off, and now be a constant issue? I will most likely drive it till she dies, as I intend to get a new one. If i chose to pull it tomarrow however, how much did it cost to rebuild yours? Thanks for all and any replies.

 

[silver eclipse]

I didn't rebuild mine, I went a head and got a evo 3, no since in rebuilding my burnt t25. What I was trying to say tho was that it ended up smoking so bad, and when theres smoke it means your burning oil, I was going thru a quart every other day. Not good had to park it to keep from seizing the hole engine do to oil loss. But once again a lesson learned the hard way, if you upgrade upgrade ,you aught to upgrade the fuel system, I now have melted pistons.
-Chad

 

[HRCEngineering]

Well, as I said I am on the Hahns super 16G turbo. I'm wise enough to know the pressure limitations of my own setup. Thanks for your input, though. with compression being 178 across the board, is there a need to wet test to check my rings? I do not see why, as i am perfect right now. I only burn about a quarter of a quart a week, if that. I do not have a heavy smoking issue, but it's smoke none the less. I always say, if something is broke, fix it. Things tend to last longer if you do that.
From people's own experiences, would you say I just need to replace the turbo gasket? ALso, seeing that I no longer smoke at only an idle and take off, is it safe to say for tonight that it is indeed my turbocharger and not the valve stem seals?

 

[HRCEngineering]

I guess I am going to pull the turbo and replace the gasket (this is what everybody refers to as the seal, or not?). It is the one located between the mating surfaces of the exhaust pipe fitting and the turbocharger, or no? Thanks everyone. Happy 4th.

 

[12sec92Tsi]

If you have no in/out shaftplay, your turbo should be good. Being that you have 178 psi compression across all 4, your safe to say that the rings are fine. Do another pressure test and open the oil cap this time to listen for hissing in the crankcase which would be your valve seals. This is what I am leaning toward from reading your post. Your seals will only make the car smoke at start up and idle, but if you say your smoking all the time I don't know what to think, maybe your valve seals are so bad that it now smokes all the time? That gasket/seal your are talking about sounds like the o2 housing gasket, which would not cause your car to smoke and that is not what you need to replace. If your turbo seals are bad, you have to tear the turbo apart and rebuild it with all new seals. Good luck and hope you get it fixed.

 

[silver eclipse]

12sec is right, the gaskets between the exhaust and turbo or o2 housing and turbo wont cause the smoking. If its the turbo you'll have to take apart the turbo and rebuild the turbo, so if its the turbo, its leaking out from where it lubes the turbines shaft, the turbine shaft housing.
-Chad

 

[HRCEngineering]

Thanks to the both of you for your input. I am not sure if there is any confusion, but to clarify it is not a THICK smoke. It is very comparable to the way your exhaust looks durring a cold winters day. What do you guys think about me driving the car around town if I must? I have a motorcycle, but that won't work on a rainy day.
Also, as my compression shows, my rings should be in good shape. I can't really see doing a wet test when my dry test was perfect. How often do you guys see the cause of the smoke being relevent to the VPC? I will listen in my oil filler passage tonight when I do ANOTHER pressure test. I do this the same way as usual, correct? Tester on the turbo inlet, pressurize, and listen in the head for the valve stem seals to leak. If different, let me know. Thanks for all of your input.

 

[staticbrainwash]

im having the same exact problem in my 92 tsi. so any help for him would also help me.

i was thinking it was my turbo, till i noticed no shaft play what so ever.

so if there is a way for me myself to check the valvel seals, i would love to know. oh, also, my compression when i got the car was 145-150 across the board, but i need to replace the head gasket soon. so that will help.

 

[silver eclipse]

If your head gasket is bad, that could be oil seeping from the oil passages to the cylinders.
-Chad

 

[HRCEngineering]

In reference to my previous post, I have concluded the turbo is fine. There is factory movability from the side by the block to the side toward the radiator. There is no inward or outward shaft movement whatsoever.
While talking with someone whom I know personally, I asked him about determining the condition of my vavle stem seals by doing a leakdown test. We decided that you would still hear a bit of blowby from the rings while listening in the oil cap, even though the condition of my rings is good. Also, there always be some valves open, causing a sound as well. If wrong, I'm wrong. I'm not making it a debate, I would like your peoples input. will I be able to destinguish a hissing sound if indeed my valve stem seals are bad?

 

[reveal1123]

im having the same kind of problem. my turbo's blown; it has a decent amount of side to side play, but no in/out play.

If your turbo seal is bad, and you pressurize from the turbo inlet, air can leak past your turbo oil seal into your crankcase/valve cover. Why not try to pressurize from the throttle body elbow to eliminate the turbo from the test to see if you have any hissing from the oil cap, which in that case it would most likely be your seals.

 

[staticbrainwash]

But if HRC is right and some valves will always be open. you won't be able to tell where the system is leaking.

there has to be an easier way to tell if seals are bad aside from pulling the head.

i'd really like to know how if there is any way to do it. . . even though im prolly gonna pull the head anyway.

 

[ChicksDigBoost]

Get a cylinder leakage tester. You can test each cylinder individually. You put each one at TDC compression when you test, so the valves won't be open.

This will test leakage past rings, headgasket, or a valve sticking open.

 

[SlowSpyder]

Theres going to be oil in the inlet if the line from the valve cover to the intake pipe is still connected. Another thing, If there is any chance a decent amount of oil is getting into the cylinder whether it be blow by or bad valve stem seals this will give you incorrect compression results. Pretty much your compression test is worthless if there is oil in the combustion chamber. Oil in the chamber will act like a seal and give higher compression results than what it really should be. Check your intercooler piping for oil, If there is alot of oil there then its your turbo. Take out a spark plug and shine a light down the plug hole. If the top of piston is all oily then it just might be valve stem seals or rings. Take your time dianosing this problem.

 

[silver eclipse]

I dont understand how the valves being open will allow a hissing if the seals where bad. All the air would go to the ports. Unless your describing a valve seat not sealing properly. I could be wrong im just a lil confused about that test.
-Chad

 

[HRCEngineering]

Thanks for all of the great replies. Having oil in my combustion chamber would affect my compression test huh? That is a great point. Having such a scenerio is similar to a wet test. I am getting agrivated with my situation and hope to have it worked out quite soon. Im really hoping it's something simple, like a $3 PCV valve causing excessive crank case pressure. Something tells me it may be that too. I remember a while back when my dipstick use to pop out, there was no smoke. Now that I think about it, I can't recall it smoking until after i kinked the dipstick tube a little. This could not be causing excessive crank case pressure and causing it to leak past my worst seals, ie valve stem seals.
Finally, I would like to know what kind of damamge I could be doing to my motor if I must drive the vehicle. Thanks everyone for all of your knowledge.

 

[HRCEngineering]

Well I just replaced the PCV Valve and checked the intercooler piping for oil buildup. there was nothing except the usual for a two week old intercooler setup. I guess I will have to pull the head, and knock out the valve stem seals and an aftermarket high pressure head gasket. What do you all think?
Thanks.
-Ray

 

[SlowSpyder]

Ive seen cars with bad valve stem seals and they tend to blow blue smoke all the time. If im correct you are still running a working cat. If thats true then the cat can also be hiding some smoke. Another thing, you still have problems with the dipstick poping out youll need to put a stronger one way check valve inline with the oem pcv valve. This will prevent any boost pressure entering the crankcase assuming its the pcv valve. Also put another pcv valve(any will do) inline with the valve cover breather line. This way you know that there will always be vaccum in the crankcase. The pcv in the breather line will allow air to blow out but not be sucked in keeping vacuum. Like I said before take your time diagnosing this.

 

[HRCEngineering]

You are saying that I should run two PCV's, one with a stronger tension than the OEM? Elaborate. I replaced the PCV with a new OEM one however I am still smoking. Also, I do have a race cat. I still haven't gotten any responses as to me being able to safely drive my car. I only lose about .25qt. every other week if that.
-Ray

 

[SlowSpyder]

You are saying that I should run two PCV's, one with a stronger tension than the OEM? Elaborate. I replaced the PCV with a new OEM one however I am still smoking. Also, I do have a race cat. I still haven't gotten any responses as to me being able to safely drive my car. I only lose about .25qt. every other week if that.
-Ray

Have you ever seen krankvents? They sell them at Dejontool. It works the same way but your not paying 100 bucks for stronger 1way check valves. This is only a cure for a oil dip stick popping off also a cure for excessive crank case pressure. I wouldnt drive it because it can only get worse. Another thing, how many miles do you drive in a week? burning 1/4 quart every other week means alot if your only driving 100 miles every other week.

 

[HRCEngineering]

Well I drove it for about 10 miles tonight and it seems like it stopped smoking at idle. It does still smoke however when I rev the engine up a little bit. it appears that all smoking at idle is gone, or atleast not noticable. I still can not determine if I smoke while driving, due to my race cat most likely. I know this, if I am smoking while driving, it is almost nothing. Do you guys think I should pull the head and have me a look?


the smoking at idle hasnt gone away.

 

[GSTurbo1]

I have the same problem, Mine looks like a diesel when I take off real hard. Still going strong though. I'm taking it off the road and building the turbo seals and replacing the valve stem seals.

 

[Bud92gsx]

I have the same problem, Mine looks like a diesel when I take off real hard. Still going strong though. I'm taking it off the road and building the turbo seals and replacing the valve stem seals.

IDK why it's needed to bring up a thread from 05. Just to say your replacing stuff.