33 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHBurning smell?
Leading reported evidence
Check serp belt as well and it seems
Performed · outcome unconfirmed
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0
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1
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I have checked my serp belt as well and it seems to be in order.
Leading evidence: 'Check serp belt as well and it seems' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, the most frequently mentioned possible cause is 'cosmoline' (1 discussions; 0 report identifying it and 1 suggest it). The most frequently discussed action is 'Check once in a while' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
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Suspected cause
That odor is probably the cosmoline that Porsche uses on the bottom of the engine to protect the engine from the elements.
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Suspected cause
I always assumed it was the tires, and I seem to notice it more after a spirited drive.
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33 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
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I have been driving my 996-4 for about 3000 miles and am constantly getting this burning smell from the back of the car like burnt rubber (don't laugh, I know!) after driving it for more than 15 minutes or so. I just changed the oil and filter on it on Friday evening and did not see anything that could be causing the smell. The car appears to be bone dry and the serpentine belt seems fine. Do these cars have problems with the parking brake shoes? It seems to be located under the hood but I can't pinpoint it... Any ideas?
That odor is probably the cosmoline that Porsche uses on the bottom of the engine to protect the engine from the elements. When the cosmoline gets warm it gives off a particular odor.
It is rubber. It's the rear tires. Touch them after they've warmed up. Probably because they have 60% weight on them, spirited driving and a very slight 'toe-in' setting.
You'll find the rear tires wear out 2x as fast as the fronts.
Same thing with my C4S. I was told it was probably the rear brakes. But the cosmoline and tire rubber make sense. It smells, but there is no smoke anywhere. I was worried that is was oil burning, but smoke would result from the oil burning plus the odor is quite distinctively not oil. It seems to be a common occurance and it goes away in about 5 minutes.
run it by your indy or dealr just to make sure it's the "normal smell"
if it is, smile.....
if they think it is not normal - set an apointment to have them look at it and ask if they think it can be driven....
nost likely its normal, namy of us had the same "what's that smell" moment, but its not a bad idea to have a second opinion since we cant actually smell it over the interwebs
Another thing to check is your serpentine belt. For old-school 911 guys the smell of burning rubber is pretty much the norm, to a point. I complained about it a few times to my dealership and they blew me off--until the serpentine belt failed prematurely. Check to see if the come-along pulleys are smooth along the belt-ridding surface, or if you have grooves along the sides of the pulley surfaces. Sometimes the belts are just too tight--and that is not adjustable of these engines. Odd!
You can look for oil leakage around the valve covers or other places that sit above the headers. In the picture you'll see an arrow pointing at oil on the header tube and some seapage on the engine. Oil can smell like burning rubber. It's all hydro carbons.
Very normal. Mine smells 25% of the time. Sometimes after a spirited drive, sometimes not. I don't think it's cosmoline though....I have a reman engine in mine and they (famously) are not coated with the yellow goop.
I chalk it up to hot tires...it's definitely a rubber smell and not a clutch, brakes or oil smell. Soft tires, lot's of toe, lot's of weight...makes sense to me although it still catches me off gaurd sometimes and make me wonder.
Oh yeah - my first 996 smelled the same.
They all do it.
Yeah, don't make a stink about the smell.
I drive mine hard enough to generate a fine dusting of rubber on my rear flanks.
The most important thing about these cars is don't ever let anyone pass you.
Run your finger along the rear bumper near the rear tires after a 100 mile drive on the highway.
Your finger will have black tire residue on it.
The tires wear very quickly.
The smell is part cosmoline and part tire rubber.
Mine does it too. Definitely smells like burning rubber. I always assumed it was the tires, and I seem to notice it more after a spirited drive. I didn't know about the cosmoline until this thread.
The best explanation I've heard: the mufflers are right behind the rear tires, so normal wear throws tire dust onto the hot mufflers. I call it the "Porsche smell".
And lastly, just to be sure it's normal, drive for 15 minutes, stop, and immediately grab the exhaust pipe with both hands to see if it's hot. I kid!!! Don't do that.
I have had my 2000 911 for a couple weeks and have been going nuts trying to figure it out too.First I thought it was coolant, although it smelled a little different. Took it to the indy shop and had it gone through and pressure tested. All was fine. Then upgraded the expansion tank cap just in case. No evidence of any leaks. My friend said it smelled a little like rubber. I drive it like its a porsche. Now I feel better too. Makes sense. I guess its time to spend my extra $ on mods.
MY tires get hot on my 99 and there is rubber dust on the tail pipes I have had it alligned several times and it is not right yet, spirited driving just makes for more heat and rubber dust, there must be a solution? halvin
Hello Everyone, First time post for me on Rennlist. I have a 2003 C4S with 34.000 miles on it. I purchased it with 27,000 miles on it. I have the same burning rubber smell. Seems to be worse on a gentle drive than an aggressive drive. My dealership told me it was because there was oil in the bell housing from a bad rms but the smell is still there. I have checked my serp belt as well and it seems to be in order. A friend of mine had an nb 911 and he said he had the same burning smell. My car is lowered as well and it smelled the same before the car was lowered. I would love to know what it could be.
Would be best to not take any smells for granted. You have to visually check once in a while. Get the car up in the air once in a while to make sure things are still tight down there. Good time is when doing oil changes.
Just my opinion of course as I'm certainly no authority on the matter, but this seems to be (typical) dealership fear mongering. I have the same type of smell but it doesn't smell much like engine oil.
