Heath

I now have approx. 270 miles on my rebuilt b20a (88 prelude) and when the engine sees lots of vacuum as if I'm driving down the highway, maybe down a grade, and take my foot off the gas it burns oil. Where could this oil be sucked from? It has new rings, valve stem seals, etc. Could it be that the rings aren't broken in yet? I replaced the pcv although it hasn't helped in the slightest.
There is absolutely no burning of oil when idling or even excelerating. I haven't taken it past 3k yet.
The only thing I can think of would be my turbo. I think it is leaking some oil on the compressor side so there's a chance the turbine could be leaking as well. If oil is leaking on the turbine side would that cause it to smoke like hell when the engine sees vacuum?
Oh, and I'm running an open wastegate with no charge piping as of yet so there is absolutely no boost going through the engine.

boosted_b16

could be your turbo, also could be your rings not seated yet, you should take that thing to like 5-5.5k rpm and let it decel several times to seat the rings if you have not done that yet

SpankedYA!

Did you have the head redone as well? Sounds like valve seals.

Heath

Thanks for the reply guys. It turns out I closed the wastegate on the turbo and the smoking on decel stopped. I'm not sure exactly what was going on but I think there was oil pooling in the turbine housing and it was being drawn out and burnt off. I really don't know. Whatever the case I feel certain it's the turbo and not the engine so I'm relieved.

mahcivic

id put charge pipes on with what ever turbo you put on next. dont wanna over spin it!

toad

dont baby a brand new engine, break her in hard