Thick white smoke on first start up after sitting overnight.

[Highway Patrol]

By the way, I checked the PCV valve the other day and it was completely fine, rattled and everything. Not looking too good :/ I'm going to try and see if I can have the LIM gaskets replaced some time this week.

[bs009]

I'm betting it's your vacuum modulator on your transmission. Mine leaked on my 94 and did pretty much exactly what you're describing.

It seeps trans fluid into the vacuum line and the engine burns it on first start up. It's a pretty cheap fix if that's what it is.

[Highway Patrol]

I'm betting it's your vacuum modulator on your transmission. Mine leaked on my 94 and did pretty much exactly what you're describing.

It seeps trans fluid into the vacuum line and the engine burns it on first start up. It's a pretty cheap fix if that's what it is.

What would trans fluid smell like if it was being burned? The smoke/steam from my car doesn’t really smell like anything in particular if to be honest. There is some type of smell but I think it just has to do with the winter gas mix?

[bs009]

I'm not really sure how to describe it, it's been probably 10 years since I had to smell it lol. It's definitely a weird smell compared to coolant or oil.
When my car did do it though the smoke was white like you're describing and thick enough to smoke out most of the parking lot

You could pull off the vacuum tube on the modulator and see if it's wet. If it is then you know it is leaking.

[imidazol97]

Forgot to add, the engine has a vacuum coming from the oil filler cap and the dipstick tube? If I remove either of them while the car is running, the idle will drop dramatically (to the point where the engine would probably die if I didn't put it back in) and I will get a terrible spark knock sound? I've got a video of the issue on my phone that I'll be uploading onto YouTube and then linking it onto here in a few. I've asked multiple people about this issue and I've narrowed it down to either the PCV valve or (as discussed above) the LIM gasket.

Isn't there a problem with the PCV having two gaskets and sometimes one has been left off. That missing gasket allows the full engine vacuum into the crankcase?

[96 SSEi]

hi, if you love your car, you will do an oil analysis for coolant contamination
you can do a budget one yourself........

get an old spoon
put some oil in from oil change in spoon
get torch and heat the oil from bottom
if there is bubbling/spitting: there IS water contamination.

I would put stop leak , change oil and retest until good.

yes, make sure pcv is correct and installed correctly

good luck

[Highway Patrol]

hi, if you love your car, you will do an oil analysis for coolant contamination
you can do a budget one yourself........

get an old spoon
put some oil in from oil change in spoon
get torch and heat the oil from bottom
if there is bubbling/spitting: there IS water contamination.

I would put stop leak , change oil and retest until good.

yes, make sure pcv is correct and installed correctly

good luck

Hey! Forgot to update you guys on everything that has happened within the last week or so. Anyways, I dropped the Bonneville off at my local shop Monday afternoon (3/25) and I am waiting to hear back for an official diagnosis! I called them yesterday and they took the Bonneville for a test-drive; it started up okay and ran great... up until he pulled back into the shop's parking lot and put it in Park, which is when it began stumbling all over the place just as I've had it do on video. My mechanic was supposed to call me back today with a diagnosis but, of course that never ended up happening. Long story short, I'll make sure to keep you guys posted this time