Occasional burning smell
Thread Starter
Rookie
Joined: Feb 2011
Posts: 46
Likes: 6
From: FL
Occasional burning smell
My 2008 has an occasional burning smell coming from it (usually after highway driving). I don't think it's oil (already replaced the fuel pump gaskets - no leaks for now). Smells more like a clutch or brakes would smell (or maybe electrical wire). But brakes are still pretty new and there's no evidence of an issue there. I don't have any codes or lights showing (yet). So I'm a little worried it might be that my 250K mile transmission might be getting ready to call it a day. Though, there doesn't seem to be any slippage or shifting irregularity. I would check the tranny fluid level, but of course it's sealed. Anyone else have this problem? How did you resolve it? Any other things to consider?
Instructor
Joined: Jun 2014
Posts: 965
Likes: 575
From: az
Spark plug tube seals leaking oil into the spark plug cavity makes a funky smell. Pretty easy to check for leaks by pulling out one or two easy to access coil packs. On mine the warmer the engine bay got the more I could smell the oil burning. I can see highway driving increase the smelliness.
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Pole Position
Joined: Aug 2020
Posts: 2,852
Likes: 1,001
From: NH
I believe, there are 4 in total - 2 in front and 2 in the back. 2 front flanges are just after 1st catalytic converters close to the foot well area.
If you have a chance, lift the car and check if there is anything too close to the exhaust pipes.
If you have a chance, lift the car and check if there is anything too close to the exhaust pipes.
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7th Gear
Joined: Nov 2023
Posts: 7
Likes: 2
From: IN
I'm chasing problems like this myself on my 07 SWB. I recently changed the valve cover gaskets and fuel pump seals. I got under the car and cleaned off all the old oil that had leaked out over the years. However I still smell an off smell on the highway and have to keep the recirculate air option on to avoid it. I'm thinking exhaust leak now.
I'm going to check the manifold to cat flanges tomorrow from under the car, looking for black discoloration indicating an exhaust leak. However the manifolds are really covered up and I'm not sure I can access the heat shields from under the car even with all the covers off. I will report back with pictures.
I'm going to check the manifold to cat flanges tomorrow from under the car, looking for black discoloration indicating an exhaust leak. However the manifolds are really covered up and I'm not sure I can access the heat shields from under the car even with all the covers off. I will report back with pictures.
Intermediate
Joined: Aug 2021
Posts: 427
Likes: 183
From: VA
Total wildcard thought. It may be your PCV valve? If your PCV valve was stuck closed it would be pressurizing your valvetrain and might lead to a smell (blowby gasses) coming from the vent hoses. The seals on those hoses arn't very tight. Just a thought.
7th Gear
Joined: Nov 2023
Posts: 7
Likes: 2
From: IN
I did get under the car with all 3 panels removed (one plastic and two metal) and you really cannot see the exhaust headers at all. The flanges and the rearmost manifold gaskets looked good without undue dark discoloration. I suppose the next step would be to try to pressurize the exhaust system with a shop vac and duct tape and hit them with soapy water to see if there’s any bubbling.
I did find a small oil leak from the bottom of the timing cover that may be flying back and hitting the resonators under the front footwells. But there was no discoloration on the pipes to indicate oil was burning on them.
In any event, the timing chain cover or manifold gaskets would be an engine out job. So it looks like I just drive with recirculating air haha.
Pole Position
Joined: Jan 2022
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7th Gear
Joined: Nov 2023
Posts: 7
Likes: 2
From: IN
I wasn't aware I could see the transmission from the top of the engine. I haven't noticed anything amiss from under the engine transmission wise. The leak from the timing cover was definitely oil. I'll give it a look though.
