bpfergu

So I have a brand new GT28RS installed that has only seen boost a handful of times. This morning I spooled it up and I noticed a big cloud of white smoke behind me. I immediately pulled over but the smoke was gone. I let the car idle for a little while and no more smoke came out. I also spooled it up a little bit again and yet again no smoke came out. I had a compression test done recently and it came back fine...I also checked the oil and coolant to make sure they weren't mixing and all looked well, so I don't think it's a head gasket issue.

In addition, the car appears to still drive fine. It's in need of a little update to the tune, but all this is causing is it to run a little lean at idle.

I was sure to attach an oil restrictor as that is the reason the first turbo crapped out.

Having smoke come out my exhaust is never a good thing, but could this just be a wierd, one-time thing?

shanebadoo

I had a big cloud of white smoke behind me one time, mine was a cracked sleeve.

bpfergu

The engine was built like 5k miles ago, and should be able to easily handle the boost I'm giving it. It's decked, sleeved, and line-honed so I would be surprised if it has anything to do with a cracked sleeve or something like that.

racebum

it's cold out. turbos reduce exhaust temps at the muffler when you're just idling around. one the AF is richer and two they soak heat as gas passes though. it may take slightly longer for the water in your exhaust to burn out. put a rag hanging over your exhaust tip next time it does that and see if it gets wet

the only other thing it could be is excessive blow by. if you have forged pistons you may have some blowby until they warm up

bpfergu

Yes, I have forged pistons. It was probably 50-55 F when I took it out this morning, and I actually hit boost probably 5 minutes into driving, when my gauges showed an engine temperature of around 185 F.

Would it take forged pistons longer than 5 minutes to warm up if I'm driving softly up to that point?

racebum

185 should be warm enough to expand unless you have really large PWC, as you said, 55deg outside, there is a good chance it's steam from water in the air. look at your exhaust pipe when it's smoking, i bet you see water droplets and this only happens the first few minutes of start up

MiraiZ

look in your radiator...check too see if there's any oil in it

bpfergu

Well I took the car out again yesterday and sure enough when I hit full boost and was around 7k RPMs on the engine, it shot out another big puff of white smoke. The second I let off the gas the smoke disappeared, and the car continued to drive and perform fine.

I can see no difference in fluid levels, and have seen no leaks. The turbo was recently replaced and I'm really starting to think that perhaps one of the hoses coming to or from the turbo isn't completely tightened or has a small cut that is causing a small amount of fluid to be forced out at high pressure. At least that is the only thing that makes any sense right now.

racebum

do a leakdown test if you have the gauge, compression test if you don't. the thing about blowby that i have personally found out is that you won't really see it under vacuum if the engine isn't totally shot, but, pressurize the cylinders and the smoke shows ring up.

if your compression and leak numbers are good, you can rule that out, if they aren't, you have your cause

bpfergu

I have recently had a compression test done and it came back fine. I have yet to have a leakdown test, though.

As mentioned earlier, the engine was recently rebuilt with all the normal top-shelf goodies and the power I'm producing shouldn't even be getting close to stressing the block or the internals. In addition, I drive like a grandma so I would be very surprised if it was an issue with the engine itself.

MiraiZ

Doesn't mean a thing...you could have raised the head. Since it seems to be happening at only WOT, I would try re-torquing the head bolts and see if the smoke goes away.

racebum

could be, he really needs to do a leakdown before guessing at harder more labor intensive chores. same with compression, the results last month mean nothing today

bpfergu

I'll try to get both done tomorrow and will come back with the results.