[Makoyouidiot]

Hey again, gents, was driving tonight back from the grocery store and while revving the engine in my '91 164 S at a stop light to impress my fiance, and getting laughed at for my trouble, I might add, we both noticed an odd burning plastic smell inside the car, we were very close to home so I checked it out when we pulled into the driveway, it was pretty dark so not positive what it was, but it was definitely coming from the engine bay somewhere. I did notice the lining on the bottom of the hood drooping a bit, could that have contacted the engine and caused the smell?

I'll have a better look at it tomorrow in the daylight and see, didn't want to stay outside tonight with a storm coming in, so possibly more info to follow depending on what I find.

 

[Makoyouidiot]

An update, looked at it in the daylight and it indeed looks like the hood lining contacted the engine and burned away a bit, here's some pics.

 

[Makoyouidiot]

Sorry about the huge picture size, I'm not totally sure how to make them smaller, but if you click on them you can see smaller versions on imgur.

 

[Alfisto Steve]

I would be more suspect of plastic covering over wire harness behind engine that is supposed to be clamped to false firewall having fallen out of clamp and melting on rear exhaust manifold. Or even front harness behind radiator area.

I doubt hood liner melted on top of engine enough to cause burning smell.

 

[dennism]

Plastic smell

Another suggestion would be to check the front right wheel liner. It runs very close to the A/C belt, and for some reason seems to sag over time.

The belt and pulley will cut an arc into the liner in a very short time. DAMHIK!

 

[Makoyouidiot]

Alright, I'll have a look at those things as well.

 

[Graham D]

I would opine that liner material would by design be pretty much fire resistant and nothing on the top of the motor gets hot enough. Right front wheel liner abrasion most likely caused by lower front motor mount failure - AMHIK; not an easy replacement either. Alfisto-Steve's opinion is the most logical and nobody, and I do mean NOBODY comes anywhere close in hands-on experience.

 

[v6junky]

Could have been a plastic bag that got sucked onto the exhaust or manifold. Does it still smell?

 

[Alfisto Steve]

Yep those dam plastic flying bags can do it, too.

 

[Makoyouidiot]

Well, I couldn't find anything else myself, and after another couple of days of driving I still haven't smelled it again, so it really might have been a bag or something. Now that I think about it, someone left a ripped sofa cushion on that part of the road and folks running it over caused the stuffing to scatter all over the road, might have been that.