Burning plastic smell?

Hello

Twice now, my wife has come home from work (40 minute drive, engine fully warm) and the garage after parking was filled with a burnt plastic smell. Haven't had the car off the ground to look from underneath, but can't find anything obvious from above that looks either melted or dripped or anything. We've had our LGT since December, and this is the first time we've encountered this. Only thing new to these two days were that A/C was used. Belts seemed fine, though. Definitely not a fuel or oil or coolant smell. Not certain that it's coming from under the hood, though. Any common problem areas to begin looking for? Thanks!

Ya know, it could be a plastic bag stuck to the exhaust somewhere. That happened to a Sentra I used to have and it smelt horrible.

 

You also might want to check any wires (Battery terminal wires, anything close to the heads or exhaust, ect...)

 

There are wires on the AC compressor that activate the unit, you might want to check those out. I'd look over the entire AC system (Compressor, lines, condensor, the whole 9 yards) just to make sure that's not causing the problem. You might need a recharge too. Modern AC coolant recharge kits have lubricants built into them. I'm not sure which model compressor you have, but I'm pretty sure some have small oil reservoirs to lubricate the internal compressor parts. None of these parts should be plastic however, so this most likely isn't the problem. Every little thing you can eliminate gets you one step closer to what the problem really is though...

 

Just to narrow it down some more, does the smell come from inside the car, outside the car, under the hood, or a combination of several? If you can try to narrow it down we can probably figure out where it's coming from fairly easy.

Thanks for the response! It could be something as benign as a plastic bag or something foreign touching the exhaust, hadn't thought of that one and I'd certainly be relieved if we find it to be something that simple! It was a bit less noticeable the second time. Bad thing is I'm now on the road (which gives me time to worry about it and not be able to do anything about it...) and will have to wait for her to let me know if it happens again. In the meantime, at least she has access to another vehicle if we decide it's a problem while I'm away.

+1 for eating a plastic bag, did once, now I avoid bags on the highway....

check the under side of your engine cover for wear spots, my svx's cover got hot and started to sag, eventually saged to the point where it was rubbing on the A/C pulley. then the pulley melted it faster and the plastic ended up getting in the bearings and killed the A/C condensor.

Thanks, lil. My table saw's plastic belt cover did something very much like that, and the smell was very much what we encountered in our garage. Was the sagging in your SVXs cover apparent without removing it? It'll be a few days before I can get a first hand look, but my wife can certainly tell if something isn't "right".

Try driving it for a day without the AC on. That is a good way to eliminate that

Try driving it for a day without the AC on. That is a good way to eliminate that

 

Nope, the only way is to get under the hood and check, the outer ring that the belt rides on it what rubs(if it is) and it is always turning even if the A/C is off. plus it could be the other acc belt or something else melting it.

 

If that's what it is then it is already too late since you are smelling plastic, it would have to be replaced as preventitive measure IMO so what's another day or two, just leave that part out when you talk to SOA.

Well, finally got under the car, and alas, no simple solution like a baggie on the exhaust or a rubbing pulley/belt cover. A few observations, though:

 

The car had been in a minor front-end wreck 5-ish years ago, according to the CarFax report. Only 45k on it when we bought it in Dec 08, 48k now. It was regularly maintained by a Subaru dealer, although we bought it from a sales and service shop that specializes in European cars.

 

A number a fasteners appear to be missing from the air dam/front end, including one from the lower right (passenger) side of the timing belt cover. I don't think it was all put together after the wreck as well as it could/should have been. There is a crack in the passenger side cooling fan shroud, but the shroud does not appear to make any contact with the fan as there is no sign of any scoring or rub damage, on either of the two fans or shrouds for that matter. Would have been a perfect burnt plastic smell source, but...

 

There is a great deal of oil, probably of different types, all over the underside of the engine. First, there appears to be some tranny fluid on the (driver's side) plastic elbow and the bottom radiator hose to which it's connected, probably from a leak at the fluid cooler fitting which is just above. There also appears to be fresh oil, not sure of the type, on the tubes that run around the steering mechanism above the exhaust y-pipe, and the surrounding areas including the engine oil pan, but the steering fluid level is not low. The engine oil was low, however. The engine oil filter and mounting area is clean. There are some signs of an older or very minor/slow leak of oil or fluid on the areas around the front and rear valve cover bolts, but the middle bolt area is clean. I'm guessing anyway, that the valve covers are the outermost bits of hardware, and the cylinder heads themselves are inboard of those and have their own gaskets that seal them to the block? Those gasket areas appear to be clean and dry on both sides. This car has not had the head gaskets replaced (2.5L).

 

Lastly, there is a gasket or weather seal made of a very soft rubber on the bottom of the center section of the timing belt cover that had about 1.5 inches of material looped downward out of the cover just right of the center. I was able to push/feed it back in, but it looks as if the seal is either kinked or twisted or at least poorly fitted at the extreme end on the passenger side and also as it goes around a fastener on the driver's side. There does not appear to be any fluid of any sort coming from this area that was left open by the loop, but there was a drop of fresh oil hanging from the loop itself. I'm guessing it didn't run down from the unintentionally exposed opening, but rather got there from the surface and found the lowest spot. I don't know offhand if the dealer we got it from replaced the timing belt(s) before we bought it, but the dealer owner did drive it frequently as a personal car while it was on his lot.

 

This car is 11 years old and with only 48k, has most likely done a lot of sitting, mostly in a garage based on the otherwise excellent condition.

Well, although I can't explain why it smells like plastic, it's definitely some type of oil dripping onto the exhaust pipe, basically at the y connection. I believe it's the differential or transaxle located just above that part of the exhaust? It's a finned body with a large drain bolt set in at an angle, between the engine and the transmission. There is a fresh drop of red fluid hanging from the drain bolt. Is diff fluid red? May be tranny fluid making its way to that spot. Still doesn't explain where the engine oil is going, though. Multiple leaks are certainly possible, I guess.

 

All of the heat shielding up- and down-stream of the y connection has oil cooked onto it, so it's apparently been leaking for a little while, again not sure if it's engine oil or tranny fluid, or possibly even power steering fluid or diff fluid. The only one that was low in quantity for sure is engine oil. Keeping at it!

I had a 95 which had sat for a couple years, and every seal had dried up and gone to shit when I replaced all the fluids. It blew out all the front seals, rear seal, tranny/diff. internal seal, and also developed a leak similar to what you describe leaking tranny fluid onto the front diff and burning up on the exhaust.

 

 

It's typical of a car that age to have the oil seals leaking, but the leaking transmission would worry me the most. Basically the only way to fix that would require removal.

Hrm. Red fluid would most likely be power steering or tranny. When the car is warm, is the power steering fluid at a normal level?

 

As far as oil being nearly everywhere and making it difficult to see where it may be coming from, take your car to a car was and spray a bunch of degreaser on the bottom of the engine (Anywhere you can get to, really) and wash all that crap off to make it nice and clean. Then, in a few days, take another peek and see if you can see anything new.

Red is also brake fluid. Make sure that is full. Loosing brakes is bad!!!

+1 Didn't even think of brake fluid...

After a thorough check of all fluids, the only one that was low was engine oil. Front diff (which I didn't know about until reading Platinum's plight in another thread), trans, brake, steering, and coolant were all within the normal bands or levels. Definitely red fluid wherever there is fresh fluid, so I guess I'll have to hose it all down with some degreaser and see what shows up!

Oh right, I forgot about front diff fluid on an auto. On the manual it is part of the tranny.

Yeah, I would have preferred a manual, but the spousal unit said 'no'. She wanted at least one auto on the property in case of a bum leg or foot injury. We're pretty active and I gotta admit at times like that as a result, an auto comes in handy, so I can't blame her!

 

Another question: Is the flywheel (or starter gear, maybe) supposed to be visible? While under the car with the engine running (up on jackstands of course...), I noticed what I guess is the flywheel happily spinning away. Seems vulnerable to rocks, water/salt, general crud, etc, but it doesn't look like there's any way to cover the places where it's visible. Just curious.

 

Off to the store for some degreaser!

Visible flywheel? I've never seen anything like that before... I'm assuming our engines are the same 2.5L SOHC? Can you take pictures of this exposure? I'm completely stumped as to what you're seeing but it certainly doesn't sound good.

There is a drain in the bottom, but you shouldn't be able to see the flywheel (part of the torque converter). The only place you should be able to see it is if you pull the rubber stopper on the top.

There is a drain in the bottom, but you shouldn't be able to see the flywheel (part of the torque converter). The only place you should be able to see it is if you pull the rubber stopper on the top.

 

Exactly. If you're seeing something that you might think is the flywheel, please take photos. Although, if your flywheel was actually exposed, I would thing you'd have a lot more problems than just a red fluid leak... *shrug*

I've never seen red brake fluid... if it's just standard dot3 stuff it'll be a golden brown to dark brown depending on age. Power steering fluid is red though.

I have a simaler problem. Except its my CV joint boot cracked and opened itself up and is spewing grease all over the place including the cat and stinks pretty bad. So if you havent yet check that out im gonna do the replacement very soon.

Here's a photo, if I'm uploading correctly. What I was thinking is part of the flywheel is visible near the screw head on the oil pan flange. In the photo, it's kind of bright, similar in color as the engine support frame. It's perfectly clean, no oil or dirt apparent. This is looking toward the rear from just ahead and inboard of the left front wheel. At the bottom is the roll bar and some power steering lines, and at lower left is the front edge of the support bracket that I guess keeps the engine support frame from flexing. The part in question spins when the engine is running. There doesn't appear to be any way to cover the opening, so I never thought much of it. It's also similarly visible from the passenger side.

Oh my! That's a lot of crud down there! As far as the flywheel being exposed, I've never seen that on my car. I have to crawl under there this weekend (most likely tonight) so I'll take a peek at what's down there to cover that area.

A lot of crud, indeed! To be honest, since we bought the car in Dec (tons of snow, bone chilling cold, etc), I never got under it like I normally would when looking at a used car. Doesnt' help that it sits so low, either:cool:. If I had, and it looked like this when we first saw the car, I would have either walked away or done some serious bargaining, as opposed to the "for fun" bargaining we did for a car that we really wanted from the start. I have a feeling this is gonna cost me!