PontiacBonnevilleClub.com

So as some here know I have been giving some love to my 2000 SSEi after its previous owner neglected it over the last year. Been one hell of a battle but I can just see the finish line..... save for one issue.

When cold at first startup it blows some whiteish smoke, not much but its there. At the same time the motor idles like crap and after a couple seconds of two or three throttle blips it smooths right out and proceeds to run fine. I also have to give it a little gas to start.
If the car sits for more than 5 minutes it once again will start a little rough and have a little smoke and I have to blip the throttle a couple times for it to come back to a normal running engine.

Car runs at 195* (scanner) and I have pressure tested the cooling system and there was no bleed down like a blown head gasket or crack would suggest. The smoke does not smell like a rich running car so I don't really suspect a hanging injector but threw some Seafoam in the tank anyway and see what happens. The smoke does not have that sweet tinge to it like coolant and its not dark or acrid like oil.
See I would suspect the IAC but the smoke is throwing me off. Are the IACs known to be problematic?

Has anyone else delt with this issue. Just figured I would ask for the stuff that may be obvious to you guys but I may have overlooked.

So no thoughts? I am guessing head gasket or cracked head. Which is more common in one that's been a tad overheated?

Id hate to open it up for some gaskets and realize I need a head and then my lift is down for a few days for shipping. Of course then its "Do I buy one head or both?" or "Do I spend $280 each for stock reman heads or go spend $1100 for CNCd heads?"

Have the LIM gaskets ever bee changed?

Lower and upper gaskets replaced last week with Felpro, new water pump, flush, dexcool, several oil changes before a mile was put on it.

On the gaskets, after speaking to Intense and 3800 Performance they both say the Felpro metal ones are a hair thinner than the original plastic ones and some people do have intake leak issues because of that. Based on that I went with the plastic Felpro gaskets as I have used them on a couple dozen 3800s over the years without issue.

At any rate, I am 90% sure its head gasket or cracked head. I am just trying to get a consensus on the more common of the two.

I highly doubt cracked heads or bad head gaskets. Both of those problems are persistent and don't go away after a few seconds. I would say its more likely that some of the valve stem seals have become brittle and are leaking a little oil into the intake runners. The smoke at startup is the oil burning off.

I Blue Deviled the car yesterday. It no longer smokes, no longer overheats after several drives and no longer stutters at startup.

So, headgasket or heads the more common issue on these motors?

I don't like sealers but wanted to test a theory and unfortunately it was right.

It must be a very small breech due to the car clearing up within a few seconds and it taking 4-5 heat cycles before enough air was pushed into the cooling system (or coolant pulled out) before the car would overheat again.

Head gaskets and heads on these aren't an issue. That is more the 60* V6's (2.8's, 3.1's, 3.4's). These are pretty much UIM and LIM. Of course if the previous owner neglected it like you said, anything is a possibilty.

Make sure the block didn't crack as well when you have everything apart. Do you have access to a magnaflux or dye penetrate check?

Doubt the block is cracked. I don't have the equipment but I am sure I can get my hands on it. Not going through that kind of hassle though, car just aint worth it. I will wait and for the Blue Devil to stop working and then see which cylinder (s) are leaking and then pull it apart and inspect the head and gasket for those areas. If both appear fine I will just get a JY motor, slap it in and move on.
I can have both heads off within a couple hours but have no urge to drop the entire drivetrain and divorce the motor and tear it down just to look for a crack. More so when everyone keeps saying how robust these motors are.
I know a couple oil testing facilities use these engines for oil tests and run them till they kill them, tear them down, line hone the mains, slap new bearings in it, put it back together and test the next batch.