What's that smell?
 

When is this forum going to add a smellerator? We have audio and video; I need the ability to post a smell...

Last summer I noticed the smell coming from under the car in the area of the rear wheels. When the car is put in the garage after a run, the smell fills the garage for awhile then goes away. Sometimes it's noticeable in the cabin while stopped in traffic with the top down. It's kind of an acrid smell, but I can't place it. Sorta metallic.

No codes.

My indy has no idea. He says the exhaust smells ok. The cats show up as a Pass in readiness status on my Durametric.

Here are the facts:

1. New tires installed last spring (2014). The previous winter replaced:

a. oil and filter

b. brake fluid

c. water pump

d. AOS, with the j-tube connecting the AOS to the throttle body

e. coolant tank, with middle section of the oil filler tube

2. Metallic? brake? smell from rear of car started last summer while away on trip.
3. On the way home from the trip, after running all day, two instances of misfire and flashing CEL (<10 s each) within 10 minutes
4. Ran ok for 1/2 h after that, then shut down for 2 h, then run for another hour.
5. No codes from generic reader. Then accidentally hit erase button after checking for codes.
6. Pulled coils - small cracks - did not replace.
7. Pulled plugs - all looked good (not old). Replaced.
8. Replaced plug tubes and o-rings.
9. Cleaned MAF.
10. Sat for winter.
11. Started well and has run well this spring. No misfires or flashing CEL.
12. This spring when I got a Durametric it showed "Fail" for catalytic converter efficiency Ready Status. Now that the car has been driven a few times and gone through some drive cycles, it shows "Pass".
13. Smell still shows up after getting up to temp.

I don't think it's brakes, as the rear brakes are cooler to the touch that the fronts. I don't see any tears in or grease from CV boots. It's not the sweet smell of coolant and the tank level is constant.

Durametric is a cool tool, but I don't know if I should be looking at some actual values, and what the normal readings for those actual values should be.

If anyone has any suggestions, I'm all ears. Please.

Check to see if your rims are very hot after driving. You may have a sticking caliper.

Burning clutch is a nasty smell. Is your clutch slipping? Or do you notice it after riding the clutch too much?

The rears are the same temp and less than the fronts, which I think is about right. Thanks for the suggestion.

The clutch isn't slipping. I'm very careful about not riding the clutch. And I do very little city driving. :cheers:

Thanks for the suggestion, though.

Second guess, parking brakes not fully releasing. Playing off the smell described as it indicates clutch or brakes. Diagnose by lifting rear and spinning tires.

Thanks James, I'll give it a try. But wouldn't that show up as hotter wheel?

Parking brakes are small so they wont create as much heat, the brake is built to dissipate heat so the temperature may not rise much.

How about a crack in a CV boot slinging a little grease onto the hot exhaust?

NVM... just saw you checked.

Here is a pic of the parking brake.

http://986forum.com/forums/uploads01...1432516432.jpg

The tiny shoes behind the wheel flange.

You know, I was actually wondering about the e-brake. The other day while going about 30k? I gently pulled on it and heard a clunk.

I haven't done the rear brakes since I got the car 9 years ago, as the rear pads still have lots of life in them, and I suspect they weren't done by the POs, so I will definitely check that out. Thanks.

My guess is parking brake as well. They can stick, and smell. I had that issue then replaced mine.

Just my $0.02: acrid smells are almost always electrical - something burns up and you smell it for a while, but they do not last. And if they do then there is usually no question where they are coming from. Metallic smells are usually something that contains metal rubbing - brakes, bearings, etc...

Smells that come and go and last for months are usually paranoia. At the very least, and having been checked out by an Indy, I'd relax and let it play out. Chances are at this point that whatever it is will give you sufficient warning prior to complete failure that you'll have time to deal with it.

Good luck...

I get that smell. always have. I was told tire compound getting up on my exhaust.

It doesn't really smell like what I would call burning rubber. I had considered the new tires at one point too, just because it was a change.

I have had that same smell but only in the fall and early spring when they use de iceing on the roads. I find it stinks on the hot exhaust.

manual or tiptronic?

Have you ruled out a minor drip from the cam cover? Mine (2001) smells of burning oil (slightly) after a long run. It has new tubes and O-rings, but the oil is coming from around one of the cam cover bolts. Most evident after I close the garage.

On the tiptronics, when they run hot you can smell a synthetic oil smell, almost like burning synthetic oil, but not... lol

Manual tranny.