Excessive blow by on rebuilt engine with 7 miles

trunks · 08-12-2010, 02:35 PM

I purchased the engine from a guy that won't call me back now. Supposedly it has 7 miles on it and was running good before sale.

Car will not start unless floored and smokes - I mean just billows white smoke that smells strongly of oil. Oil is pouring out by the rear main somewhere - assume it is the rear main from all the pressure. There was oil in the exhaust when I pulled it as well.

I tried to get it to run decent for 3 weeks and finally took it in. Shop says terrible blowby and that it needs new rings. They said it was finally not smoking as much at idle after running a while, but when you hit the throttle it smokes terribly again. Compression they say was around 100, but I'm skeptical since I got that cold.

I did have some difficulty getting it to start and I'm worried I washed the rings from cranking? Before I say yes, tear it apart I'm wondering if there's any chance the rings will seat from more running or if it's too late - or just installed wrong?

Thanks

dented_coffee · 08-15-2010, 04:54 AM

White smoke sounds more like coolant burning to me. But anyway. Change your PCV valve. There really cheap and extremely easy to replace. Some one here on tuners just got this advise from me a few days ago and it fixed there oil problem.

100 psi is way past the service limits. The serive limit is arround 120psi if I remember correctly. You might have a warped head or a cracked headgasket. Im telling you the white smoke pouring out of the exhaust has got to be coolant burning. The oil gushing out of the rear seal might just be the rear main seal has gone bad or dry rotted and has become stiff and no longer sealing on the crank.

As for the back compression the valves might not be sealing correcly from possibly beeing bent or not installed correcly by the person who put it together. That or the rings might be shot. Try putting 1 cap of oil in each cylender then do the comression test. If the compression goes up then you know the rings are bad and might have caused washout on the cylender walls.

If your headgasket cracked and your burning coolant then make shure your thermostat isnt blocked by a big air bubble or frozen shut. A bad thermostat that dont open will not let the coolant flow to and from the engine. Thats what might have caused the headgasket to get cracked if it is.

I hope any of this helped you out alot. Also Im sorry for typing such a long reply. Im just trying to cover all of the problems and possible problems to help you know what to look for on your quest to getting her running again.

teenvette77 · 08-15-2010, 05:31 AM

I know this is gonna sound stupid but sometimes we have to check the lil things first. Hell, we sent a 911 GT3 to a shop in Ohio because no one checked the gas level in the gas tank...yeah...needed a tune anyway, lol.

If this engine truely only has 7 miles on it...what kind of oil are you using? Conventional? Synthetic? Synthetic is the only reason i can think of that a brand new engine, built properly, would have that much blowby....i know, stupid question but just checking the basics.

keltalon · 08-16-2010, 04:08 AM

Quote:

Originally Posted by trunks

I purchased the engine from a guy that won't call me back now. Supposedly it has 7 miles on it and was running good before sale.Thanks

Well if he wont call you back you really don't need a shop to tell you something is not right with the engine that's why he sold it in the first place IMO. Its a shame when people do things like this

Hope you get it right so you can enjoy your car soon

trunks · 08-18-2010, 09:56 AM

I'm in the process of pulling the engine. I'm putting a whole new block and head in because I'm tired of f'ing around. Got it locally this time which is what I should have done the first time and the guy is going to help me with install too.

I ran the old one for 15 minutes at 4000 rpms in a last ditch effort to seat the rings. Compression tested still around 100. It stopped smoking so much at idle but puffed pretty good under throttle - classic ring symptom I'm told.

White smoke is oil sometimes - when it gets into the combustion chamber or a toasted turbo. I really appreciate the replies. I really want to get my vr4 on the road after 6 months on the stands!!