Davy Bass

Hey guys,

I picked up a 99 Trans am ls1 with a v9 vortech supercharger and I'm having a problem that might be bigger than I'm hoping. It's low miles, 40k original, but I'm pretty sure it's been driven hard as its already has a new trans put in. I got it pretty cheap so that much is good.

Here's the problem... It blows a lot of steam from the oil cap and dips tick (if I open them whole running). It does it when it's cold and hot. More when hot. It's a lot of steam and it is puffing out like a steam train. Comes out the exhaust too. A decent amount of condensation out the tail pipes. I replaced the oil and didn't see really any water in it (no fluid water or milkyness) except just a very small amount on the dip stick. Nothing obvious as far as oil in the coolant either. It's white steam, not blue smoke. It seems to run fine and have full power. The car has sat a LOT over the last few years so I understand it could be just condensation working it's way out. But it's a lot of it. And the pulsating puffing leads me to believe maybe bad rings or something? Any way to tell before having to do a compression test? (since the blower is there, that will be a pita. No room)

Is this something that I should be really concerned about? Or just let it be and see how it does? I haven't driven it barely at all since I got it (when I didn't notice the problem and drove it 200 miles fine)

LilJayV10

iTrader: (39)

Watch the oil and coolant level to see if you are loosing either.

Davy Bass

So far I haven't noticed any loss of oil. Coolant was low so I'll watch that now that it's refilled. Has anybody had the steam puffing out from the oil cap like this?

Darth_V8r

iTrader: (4)

What does the oil on your dip stick look like?

Davy Bass

Pretty clean. I saw a tiny bit of milkyness on the edge of the dip stick, but that was all

LilJayV10

iTrader: (39)

If it has been sitting for a long time it could be condensation burning out of the crankcase. It can also mean that you are getting excessive blow by past the rings.

Davy Bass

Could the pulsating puffing (like a steam train) exist if it was just steam from the crank case?

Darth_V8r

iTrader: (4)

Try changing the oil. If it starts doing it and you get milky oil again you can rule out condensation

Taxman20

iTrader: (11)

Could be the crank rotation causing a little pressure next to the end of the dipstick causing the pulse. It might just be condensation. Do what Darth said. Change the oil and see what happens.

speedtigger

iTrader: (16)

Do a compression check on all 8 cylinders. The pulsating/puffing has me thinking you might have some piston damage.

Taxman20

iTrader: (11)

I was going to say that but I was trying to get him off easy.

gagliano7

Since it is supercharged make sure all the pcv hoses are routed correctly for your setup.

stevooo1181

[QUOTE=Davy Bass;19095989]Hey guys,

I picked up a 99 Trans am ls1 with a v9 vortech supercharger and I'm having a problem that might be bigger than I'm hoping. It's low miles, 40k original, but I'm pretty sure it's been driven hard as its already has a new trans put in. I got it pretty cheap so that much is good.

Sounds like ur crankcase pressure is building and escaping where it can.
I had the same issue with a old SBC when the PCV system got plugged up.

Davy Bass

Am update for anyone who may come across this later.

I​​​​​​ heard from a prior, prior owner that it had a blown piston ring on one of the cylinders. It makes sense. I would occasionally get a misfire cel at high rpms too. The car also had some oil residue in the engine ba​​​​​​y.

I actually sold the car a long time ago now while it was running pretty normally. I never drove it hard so I didn't have any problems with it really. It will probably need a rebuild.

I hope for the next buyers sake that that's wrong but it makes sense. Course the guy who sold it to me like that lied so I guess I can't take all the blame...