Update: Smoke From Under Valve Cover - Compression Test Results

[Steve95GST]

Alright, here's my problem... D see bottom of post for reader's digest version**)

Just got a built 6-bolt swapped into my 95 GST. Shortly after, I blew the headgasket (only thing that wasn't aftermarket on the entire engine, go figure ) so it was replaced with a 4-layer metal HG from Mitsu.

After changing the head gasket out, I started the car up, and besides the idle surge I was experiencing prior to the HG blow, it ran good, and sounded good. Shortly thereafter (before I even drove out of the garage ), I heard a cracking noise, at which I turned the engine off. Inspected everything over and under and noticed a small hole in the lower timing cover just below the oil pump sprocket. Upon further inspection noticed that a broken piece of bolt had fallen into the timing cover during re-installation and had caught on the timing belt and shot out of the cover. Checked timing, its was still perfect, so the timing belt didn't slip off, but it put a gouge in the belt. So I went about changing the timing belt. Now I start it back up and noticed the idle surge, and high idle, again, but still sounded good. Turned it off and checked the timing again, and it was still perfect. So I mess with the idle settings on the MAF-T and then take it for a test drive to see how its running.

Now here comes the problem...when I come back I noticed a little oil around the oil fill cap so I take it off and find some white smoke pour out. After letting it out, I started the car again and check the oil fill cap again, and more white smoke coming out. It almost smells like exhaust. Now I'm aware of blow-by and what not, but it seems a bit excessive for a newly rebuilt engine. The only negative thing that happened was after the timing belt change I let it overheat slightly on accident due to the temp sensor being unplugged (totally different story), and the only other thing that is out of normality is that when I topped off the oil before I took it for a drive, I over filled it slightly.

**To sum it all up...

Freshly built 6-bolt swap into 95 GST, high idle, and idle surge experienced (beleived to ISC, problem is being diagnosed). Blown stock headgasket, replaced with mitsu 4-layer HG. Broken bolt put hole in timing belt after HG replacement, and Timing belt changed. Overheated car once, and oil is slightly over filled. Now experiencing white smokish vapors from oil fill hole in valve cover, but seems a little excessive for blow-by on fresh engine.

Any input, help, or suggestions would be greatly appreciated. Thanks for your time...

 

[ZachM31]

The only thing i can really think of, that would cause the white smoke, is maybe some coolant got into the oil when the head gasket went, and then when it gets hot, the coolant vaporizes inside the engine (the mixture of coolant inside the oil) and that is where the white smoke comes from... unless of course the oil was drained prior to the head gasket change, then no coolant should be in there. It could be the oil burning as well, hard to say. Could also have a warped head due to overheating the engine. That is my thought at least.

 

[Amazin' Wasian]

Did you have your head and block decked? if you didnt your head is probably a littled warped and its not creating a good enough seal, do a compression test and let us know how it goes.
-nick-

 

[nc90awd]

make sure your pcv valve is new and definatley do a compression test. Even though it looks white smoke its most likley oil smoke and not antifreeze. Good luck

 

[Steve95GST]

My next step is to do a compression check, I was going to do it last night, but got very lazy. I'll post some numbers when I get it done. Thanks...

 

[Steve95GST]

So when I got off work, I took the car out to warm it up for about 5 mins. Got back to my shop, opened the hood, and sure enought I opened the oil fill cap and more smoke. So I did a compression test and here are the results:

(From cam gears to thermostat housing)
193 psi
190 psi
191 psi
192 psi

If I'm correct thats pretty high compression(Per vFAQ, the standard compression is 164, with a service limit of 121). I'm completely lost, and not sure where to go from here... Thanks for your time.

 

[andymoraitis]

Your compression is very high, which either indicates that the tester is incorrect or you have so much carbon buildup on your piston tops that it's affecting compression readings. Just for kicks, I'd try again with a different tester. FYI, strong compression on the 2G's is 180. The 1G's are 160-165 since they have a lower compression ratio.

If you see the same results, shine a flashlight into the cylinders with the plugs removed and look for deposits. If you see deposits, run a couple of cans of Seafom through the motor by disconnecting the vacuum line from the BOV to the manifold and sucking it from the can with the motor running. Let it sit for 10-15 minutes and then take it out and stomp on it until it stops smoking. Re-check compression and repeat if deposits are still evident. When you're done change the oil.

I had issues like this with compression that was too high and running with a leaner air/fuel after cleaning off the piston tops helped a great deal.

Let us know what you find on the re-check with a different compression tester.

Andy

 

[Steve95GST]

Well, I don't have another compression tester, or know of anyone that has one. And I don't feel like buying a new one. I'm rather confident that its in proper working condition, its fairly new. I did check into the cylinders, and there is what appears to be an excessive build up of carbon. When I had changed the head gasket out, I checked the pistons and head, and there was little. What little was there I cleaned up pretty good before re-installing the head. So, the plan is to try some seafoam, and see what happens. Hopefully, it will get my compression back down, which will stop the excessive blow-by. Thanks for all your help, I'll keep this updated...

 

[Steve95GST]

By any chance does anyone think that these symptoms could be caused by my timing being a tooth off? Just curious, because, though I think my timing looks right, it is the first time I've ever tried to change the timing belt...

 

[ZachM31]

You'd know if your timing was off, your car would basically run like ass, and i am sure you would know when that happened. Don't get me wrong though, your engine would still run..

 

[Steve95GST]

Well, I finally got around to running the Seafoam through the engine, turned it off, and let it sit for about 5-10 minutes. Then took it for a spirited ride. Came back to the garage, and ran a compression test and, though a few of the numbers dropped, the compression is still pretty high. This time it was 185, 190, 187, 192 (from cams to throttle body). I'm confused, and don't know where to go from here??? WTF

Anyone have any more ideas? Should I try running some more seafoam through it??? Its getting close to spring/summer and I'd like to start tuning and getting ready for the race season so I can make it to the track this summer...

Thanks

 

[Steve95GST]

Help? Anyone???

 

[Steve95GST]

Ok...I'm still having this problem, and now I've noticed some bluish/whitish smoke from the exhaust... Anybody who has any ideas let me know?

-Steve

 

[Steve95GST]

Help? Anyone?

-Steve