Sr20 smoke under boost

[Kingofthegutter]

Okay so I have a huge amount of white smoke coming out of the rear of my car under boost I believe it's white and I have no idea what is causing it, I've done a compression test and it is even across the board, I've checked the turbo on the intake side and it has zero shaft play. I've only recently bought this car and am waiting on an exemption to be able to drive it so I haven't taken it for a big drive only around the block so I can't tell if its loosing coolant or oil. It's a 1990 red top sr20det I've got a apexi t28bb turbo haltec sprint 500 ecu, 555cc injectors and supporting bolt ons

[Kingofthegutter]

Also I replaced the spark plugs 3 days ago and have just pulled them out and they have some black carbon on the end and no trace of white residue from coolant

[fliprayzin240sx]

Whats the compression? White smoke is usually coolant, usually comes from blown turbo or bad HG.

[Kingofthegutter]

It's abit low 130psi across the board with a 1psi variance between

[lok]

Where is your PCV routed?

[Kingofthegutter]

Straight into the intake manifold

[fliprayzin240sx]

It's abit low 130psi across the board with a 1psi variance between

Drop a cap full of oil in each cylinder and see if the compression jumps up. If it doesnt, then I'd say HG.

[Mikester]

Could be blow-by. I had a similar issue with my 180SX. Smoked like a bitch till everything warmed up (big drive lol); then it would be fine. I cleaned the PCV valve & put a catch can between the PCV & intake, which took care of it. However, doing the catch can technically only stopped the symptom; not the problem. Weird thing is that even tho the catch can would fill up, I didn't ever seem to be losing oil... But I didn't care because I knew I would be breaking the motor down soon anyway~

If it's blow-by, I'm pretty sure the only way to really fix it is to do a rebuild.

Could also be valve stem seals worn out allowing bits of oil into the combustion chamber(s)... Wouldn't really take much to cause it to smoke fairly obnoxiously.

If I were you, I'd start by cleaning or changing the PCV valve. Hopefully that's all it is; but I'd bet with the mods you have that the PO drove aggressively on a regular basis.

[Kingofthegutter]

Yea it does the rings are slightly worn but all evenly, and it doesn't blow a drop of smoke untill on boost

[fliprayzin240sx]

Well if its blow by, take the crank case line off, feel the air coming out of it if its pulsing. If it is, time for a rebuild. My last SR blew #3 and was pulsing/puffing smoke out of the crank case. No fucks were given, cranked the boost up more on the GT3582R and still drifted on it like a madman.

[Kingofthegutter]

Yea it's pulsing, I've installed a catch can that is vented via a small filter on top and it has stopped smoking.

I know it's only masking the problem but I am rebuilding in a month or two and I don't drive the car to often