Smoking after new head install good compression

[mjboehm]

I have a 1990 tsi with a 2.3 liter stroker just put at rebuilt head on my car. I used a mls hg and I also had the head cleaned,decked, mangfluxed, etc. I went to start my car it started smoking like it did before. I did a compression test the results were 190,185,180,190. The motor has less than 500 miles on it. The car didn't smoke at all until after the rebuiled.The problem started after my 16g died. I put a new turbo on it. How long does coolant and oil stay in your exhaust b/c this has been doing it for a will now and I don't know what else to do with the car. Any suggestions would be great.
thanks

 

[kristmen]

When you rebuilt the head, did you replace the valve guides too? Need some details on the type of rebuild. Basic valve job? Major gut and overhaul etc...?

I had a head we rebuilt but did not replace the valve guides and it smoked still. Turned out the valve guides were worn to hell. Replaced them and the smoking stopped.

You can remove your manifolds and look in threw the ports to see if there is oil on the tops of the valves.

 

[bastard dsm]

not the guides but the valve stem seals, if you had a turbo go out and it had alot of oil in the
exhaust it will take some time for it to go away. if you had the head redone did you get new valve steam seals?
also a new motor will smoke a little, does it smoke on hard decell?

 

[mjboehm]

It was a basic rebuild. The valve guide are new. It smokes while idling. I am going to let it run for a while and to what happens. There was no oil on the pistons. There was no oil on the plugs. There is no coolant in the car. I will try to get some pics tomorrow.Thank for the help.

 

[mjboehm]

Well the car smoked as soon as I started it up. The valve guides are new. The car smokes at idle. The motor never smoked when I first put it together. It all started with a bad turbo. There is no oil on the plugs and no coolant in the car and the smoke is dark gray and as it picks up idle it smokes more as the car gets hotter so I am going to try to let it run for a while to see what it does. Any other suggestion on what I should check.
thanks alot for you input.

 

[bastard dsm]

well if the guides are new then it has new valve stem seals. it will smoke for a while just drive it
to get all the extra oil out the exhaust.

 

[mjboehm]

Has anyone heard of a tb leaking coolant in the intake manifold?

 

[Maglin]

I had a buddy running stock exhaust that had a turbo just puke a ton of oil. It took a good 3-4 weeks before the car stopped smoking. It also had perfect compression (175 across all 4). But I've also seen a brand new rebuild head with new guides and improperly installed valve seals smoke the instant it starts and never stop. It also got progressivly worse the longer it idled.

 

[1bad92awd]

It very well could take a while depending on a lot of factors as to how long it will continue to smoke for. I had this problem with my car about 3 years ago when the oil return line to my T25 rusted and broke off on a 90 degree day. I drive my car daily and it took about 3-4 weeks for the car to stop smoking completely. That is partially because the oil will run through your entire system. Not just inside the engine, but depending on how long until you get everything rebuilt/replaced it can run through the exhaust. It seems to me that is similar to what you are experiencing and I would just say try to drive it and see if the problem persists or if it seems to be getting better. I hope some of that helps.

 

[mjboehm]

Thanks for the suggestions. I think I am going to do a coolant pressure test on the car to make sure coolant isn't leaking any where after I do that I am going to put new plugs in the car and just let it run for a while. This might be a dumb question since I have good compression is there a chance that the hg didn't seal and still letting coolant and oil in the cylinders. I looked didn't see any oil in the cylinders when I pulled the pistons looked wet but I looked at the plugs and they smelt like gas. When I ran the car the I used the old plugs and it staled out thats when I seen the piston looking wet and the old plugs looked pretty bad and smelt like gas.If I let it idle and doesn't overheat the hg isn't leaking coolant any more correct.Thanks for the help I will keep you posted.

 

[xlMcMlx DsM]

Take the plugs out and disable the fuel and crank the car with the radiator cap off. Movement of fluid is good, but watch for any bubbling. That means compression is leaking from the combustion chamber into the cooling system. Also, what color smoke is it? I don't think you mentioned it.

 

[mjboehm]

The color of the smoke is grayish color. I wil try that tonight when I get home. Well the compression was 190,185,180,190. I thought was really good on a newly rebuilt stroker. Thanks for the help.

 

[mjboehm]

Went home tonight and cranked the car I had one bubble in teh coolant system that is b/c i added a little other than that none, cranked the motor 4-5 time 10 second intervals. Now what should I do next beside let the car run for a while. I am going to take off the exhaust manifold to see if the vavles are wet and look into the ports. Should I still do the coolant pressure test.

 

[xlMcMlx DsM]

Yeah, a system pressure test wouldn't be a bad idea. You'd be seeing a bluish smoke if you were burning oil. I'd go with what 1bad92AWD said, and drive it for a while and see what affect that has. Check your oil and coolant a lot during that time, though.

 

[mjboehm]

Well I looked in the muffler it is coated with oil pretty bad so I am just going to let the car run for a while and hope that works. Thanks for the help I will keep you guys posted.

 

[keltalon]

Update

 

[toofast82]

you very well might just have to run the car for awhile to clear out oil in the exhaust. It may be improperly installed valve seals as mentioned too.
I was curious how you are oiling your turbo? do you have balance shafts? what turbo do you have on there now?

 

[mjboehm]

Haven't ran the car much this weekend haven't felt to good plus being really busy at work. I have to ss lines that connect the turbo to the head and oil pan. I am runnin a to4b-vtrim(oil cooled only). I am going to try to run it some this weekend. I also might take off the the down pipe and the test pipe and clean them. I will keep you posted. Thanks again.

 

[mjboehm]

I ran my car noticed that there was oil coming out of the exhaust manifold. Took the manifold off and found that there was oil in all four exhaust ports. If do a leakdown test will that tell me if the valve guide seals are no good and well it also tell me that the hg sealed or not. will up load pictures in a little while.

 

[mjboehm]

Here are the pictures.

 

[mjboehm]

Well after cleaning my mainfold and cylinder head I let the car run again and cleand everthing again.I let it set for a couple of hrs. went back and touched the vavles and noticed there was oil on them. So I am guessing the problem is the valve guides. Correct?

 

[sschambers]

I read through everything on this thread, seems like a similar problem I had. I'd start my car up, motor sounded great, didn't smoke. Until it reached around the normal operating temp, and I'd notice smoke from under the hood and smell oil bad...Also some smoke was coming out of the exhaust. After replacing the turbo for a new Bastard 20g and having it still smoke, I found out that all 4 exhaust ports on the head were saturated in oil, and to top it off I had a major crack on the underside of the exhaust manifold and it was spitting oil out of the crack and was spraying it all over the O2 housing, causing the smoke from under the hood.
After seeing that I had 180 compression on all 4, I got frustrated and just pulled the motor knowing I had either bad oil rings (won't show up in a compression test) or bad valve stem seals.

Tore the block apart, the oil rings seemed a bit worn but nothing major. I didn't touch the head, I just took a bare block and complete head to the machine shop. I figured I'd let the machine shop do the head work since I don't have the proper tools for head work.

Talked to the guy doing the machine work yesterday. He said the valve stems were in horrible shape which was more than likely causing my problem.

Block got hot-tanked, decked, head got decked and rebuilt with all new valves, stems, retainers, springs, etc etc.

Crank was sent out to be welded, re-balanced, polished. Was told everything should be done by the beginning of next week. I'm going to stress the fact that he must check, re-check, and triple check all clearances, proper fit, etc. Then when I get it back I'm going to triple check his work.

Anyway it sounds to me that you possibly have bad valve stem seals. Like mentioned before, an improper install will make it smoke, doesn't matter if they're new. Just like installing new piston rings up-side down. They'd be pushing the oil up into the combustion chamber, rather than scraping it downwards. New parts don't mean jack, it's all about how it was put together.

 

[mjboehm]

I am going to replace the valve guide seals starting this week. If this doesn't fix it I am going to get another head rebuilt. Thanks again for your help.