mhayes2344

iTrader: (3)

I have a 96 lt1 that has white exhaust smoke only at idle and only after it has warmed up. This problem didn't start until all of the mods in my sig were installed. It has been smoking for at least a year (I've put maybe 3k miles on it with the smoking). Over this period of time it has not gotten worse. The smoke seems to have a lot of moisture in it.

I know white exhaust smoke usually means burning coolant/head gasket leak. However, the car does not run hot (never gets over the first mark on the temp gauge) and does not use any coolant. I also know that smoking at idle only tends to be worn valve seals, but this smoke does not look like burning oil (I've had bad valve seals and this is not the same).

The car does use a decent amount of oil, but I'm sure a lot of the oil consumption is due to leaks that I'm tired of chasing. The oil looks normal, as does the coolant. I have noticed when its colder out, If I'm only making short trips, there is a yellow/white buildup in the oil fill cap. Compression is also good. Aside from the annoying smoking at idle, the car runs good...Any ideas on what the problem could be?

Wicked94Z

iTrader: (26)

sounds like a leakdown test would benefit you here. Hard to diagnose over the internet.

mhayes2344

iTrader: (3)

Thanks for the advice. I'll see if autozone or similar rents out a leakdown tester tomorrow.

I should also mention that the coolant temp gauge gets it's reading from the water pump instead of the side of the head (thanks to the previous owner putting a steel plug in the original coolant temp gauge location)...So I guess it is possible that the motor is running hotter than my gauge is reading.

Also the car is not throwing any codes...Anyone else have any ideas?

mhayes2344

iTrader: (3)

update: I noticed today that there was a very small amount of coolant in the oil fill tube. Still not sure why I'm seeing excess moisture in the exhaust without loosing a noticeable amount of coolant. However, I noticed the PCV valve was not working correctly. The hose was nearly cut in half. I replaced the PCV valve and hose...still had the white exhaust smoke after the car warmed up.

Today I checked the rocker arm adjustment using the EOIC method, and I don't think any preload was set. So I re-adjusted the driver side using 1/4 turn preload (Is this the correct amount for ls7 lifters?). I'm going to do the passenger side tomorrow...then I'll see where we're at.

robsquikz28

iTrader: (246)

Did you ever check to see if there is antrifreeze in the oil pan by pulling the dipstick?

mhayes2344

iTrader: (3)

robsquickz28 - Yes. The oil on the dipstick looks normal. I'm going to do an oil change tomorrow and see how the oil looks...but as far as the dipstick goes, it looks clean. The coolant in the overflow reservoir looks fine as well. The radiator is also full.

I should also add that the exhaust does not smell sweet like burning coolant...just seems to have an excessive amount of moisture in it. I drove the car for a good bit today, after adjusting the roller rockers on the passenger side and once I got home, I let it idle for a few minutes. The smoke was still there....I'm really lost here.

Edit: I also pulled a few plugs in both heads today and they all looked fine...

SS RRR

iTrader: (2)

It can really only be three things: Coolant, oil or condensation. I see you live in VA. It has been horridly humid here for the last several days. Maybe that's one possibility. I would say it's more likely oil though. Especially since you say it's at start up and that it uses oil.