My 2000 SE just passed 47000 over the weekend. For a few weeks now I've been noticing a faint odor of coolant inside the car, much to my dismay. Also have noticed, on occasion, the odor of melting (not burning, just melting) plastic in the car. All vents are clean (no obstructions, nothing within the vents) and I have good heat. No noticeable leaks inside or outside the car, engine seems clean, nothing appearing on the driveway.
Mechanic has not located any sources of coolant loss as well (I had him check the last two times my car was in for other things.)

Am I going crazy? What could be the cause of this condition? It'* driving me nuts. I'm sorry I can't be more specific in my description, but I'm hoping for some possible explanation anyway, so I can stop this maddening problem....
:?

thanks for this post. when i was driving the other day, i too smelled something. i couldn't put my finger on what it was and now you hit it. i too smelled coolant. now i gotta go out and figure out whats leaking. thanks.

Both of you are running the dreaded plastic upper intake. If you're not losing coolant, I can't explain it.....but if you are, then that upper is the prime candidate. Either the seal between it and the lower, or your upper is cracked. You won't be the first, and it'* not that big of a deal to fix. Just keep close eyes on it and keep us posted.

I'm closely tracking the coolant level as of yesterday. Would there be any obvious signs of loss other than the actual level (i.e., anything exhaust or performance-related?)

Thank goodness for extended warranties. I've got this baby covered to 100,000 miles.

Notice the time of year the need for heat has caused the rise of the smell. I would say it is plastic, but may not be melting or may be settling.

Ty

If you have a crack or bad seal, you will lose coolant (if you're smelling coolant). It doesn't take much to be able to smell it, so it might be minor. Keep watching. Not critical yet.

i smell the coolant, but i am not loosing any i've been watching it and it hasn't dipped down at all. i will keep watching it. with my high mileage (130,000), i prolly have a crack somewhere. but i can't find it right now. the seals look ok tho. i'll keep a look out.

Keep me updated in case of the worst. I'm intimate with the top end of the L27 now. Jseabert is too. Email me and I'll give you pics of his top end teardown for this same problem.

I had the same problem (a little worse actually) on my 89. I blew out the frost plug that leads from the block heater to the coolant lines and had a total loss of coolant, the melting plastic smell is glycol (coolant) it burns a clear white smoke but the smell is noticable. If coolant is leaking and its causing smoke...then there is a hole somewhere

Or willwren is absolutely correct, your plastic intake manifold is cracking and you are losing coolant. Long term it could so some serious damage, keep your eyes on it though. The Series II was built with a plastic intake manifold, whereas the Series I 3800 is aluminum.

I pulled this from another forum...take a read...

You have about 10 seconds at highway speed to pull over and shut off your engine before the bearings are scored.

The type K in its current design is a piece of ****.

But don't worry, the dealers all stock new plastic upper intake manifolds (ask them if they stock the Series I aluminum intake manifolds)

Problems with the plastic intake manifold include: warping, creep, and cracking.

Best case you need to replace the upper intake manifold gaskets, worse case (mine) you need a whole new engine.

I didn't write this, this was written by another anon. owner. I don't mean to strike fear or panic into the hearts of Series II owners..but it helps to be aware

Good luck

Careful! The Series 1 went from 92-94, and had a PLASTIC upper intake. The Series 2 ran from 95 to present and also had a Plastic upper. This is for NON-SC cars only. Bonnevilles with the 3.8 from 91-back are not referred to as the Series 1, but did have an aluminum upper.