houndcomp

I recently purchased a 92 SC400 and have been trying to fix it up. I have noticed it running a little rough and not having the power it should. I have done a complete tuneup, plugs, wires, dist cap and rotor with no change. I have also fixed a front seal leak and replaced radiator recently. I notice a white cloud of smoke on startup sometimes. What looks like excessive blowby to me when removing oil cap, puffing exhaust from oil cap. Also if i remove the air filter pipe from throttle body there is white exhaust coming out of throttle body while idling, giving it a bit of gas of course sucks it back into throttle body. There also seems to be oil puddling in throttle body pipe a bit, wipe it clean and its back in a minute. Any idea what would cause this?

houndcomp

BTW, this seems to be a recent development. Two months ago it ran like a scalded dog. I do not think it is the engine itself or even the head gasket. Possibly gasket, but doesn't seem like it to me. Any ideas?

scott101

I think you can tell if its the rings by pulling out the pcv hose when the motors running. if theres a good amount of smoke/steam then a lot is getting past the rings=blowby

thats what Ive read, hope that helps
-scott

vangb2

iTrader: (2)

+1 to this.

Also scorn cylinder side walls and warp pistons can really cause these types of effects.

houndcomp

So, I am finally getting around to working on this. Can anyone provide me with some ways to diagnose the issue rather than just saying it is rings. I understand it can be rings, but it could also be head gasket or valves right? How would I go about diagnosing it to find out what I am dealing with?