Burning Smell

willmapp

Member
:
Mazda CX-7
Hi everyone,

It has been a long time.

2 quick questions.

Has anyone experienced a burning smell coming from the heater? I'm not talking about the new car chemical burn off smell, I am asking about a distinct, sweet (aromatic, ester-like) smell that reminds me of burning hair grease, or other hair products. This happened just last night after returning from a trip. I could also smell the smell in the passenger side engine compartment.

Second question; on cold mornings does your engine rev really high on startup? When we start the car, the engine roars to a fairly high RPM.

Either way, the car is going to the dealer tomorrow.

A penny for your thoughts,
Will
 
1) If it's sweet, it may be coolant. Normally the heater core is behind glove boxes. Coolant is routed through there and air is blown across it to heat it. If there is a leak, you will be getting the sweet smell especially with the heat on.

2) Yes. It makes me mad because to me the lube system isn't up to par yet (viscosity and circulation). I like letting the motor take its time to warm up.
 
1) I've had that once...and not again. I wrote it off as someone else's car.
2) Yes...up to 2k, then 1.5k and once it settles down to 1k I'll move but not before then.
 
offset_98 said:
1) I've had that once...and not again. I wrote it off as someone else's car.
2) Yes...up to 2k, then 1.5k and once it settles down to 1k I'll move but not before then.

Ditto to everything.
 
it revs high because of the catalytic converters... higher revs on cold starts helps bring the cats up to operating temperature quicker (they dont do their job when cold), even my car does that.
 
1. Still the smell is unnatural and shouldn't have happened. The dealer couldn't make a determination but also caught a whiff of it. As everyone else has said, the smell has not come back.

2. I can't buy that about the catalytic converters. I have driven everything and own an Audi and Porsche in addition to this car. Even on cold mornings those cars don't shoot up to 3500+ RPMs and then hold for a second. 2000 max and then settling down immediately I'm following the same cold start procedure:
- Turn on the ignition and pause to let the PC adjust for temperature
- Crank the engine

If it is normal, it's normal, that was my main concern.

This is the first Mazda that I have owned, and I need to learn a lot more about these cars.

Thanks
 
if ur car is reving to 3500 rpms thats not normal, and yea def get it checked out.

I think the standard so far for cold mornings with the 7 is 2k rpm then down to 1.

every car ive ever owned has done this during winter time, nothing out of the ordinary at all its just warmin itself up.
 
willmapp said:
1. Still the smell is unnatural and shouldn't have happened. The dealer couldn't make a determination but also caught a whiff of it. As everyone else has said, the smell has not come back.

2. I can't buy that about the catalytic converters. I have driven everything and own an Audi and Porsche in addition to this car. Even on cold mornings those cars don't shoot up to 3500+ RPMs and then hold for a second. 2000 max and then settling down immediately I'm following the same cold start procedure:
- Turn on the ignition and pause to let the PC adjust for temperature
- Crank the engine

If it is normal, it's normal, that was my main concern.

This is the first Mazda that I have owned, and I need to learn a lot more about these cars.

Thanks

you never said 3500+ rpms before... AFAIK it should not go that high, even on cold starts... I would get it looked @ for that then..... my MSP usually hits 2000-2500rpm and settles back to 1k after a minute or 2.

cars on the lot (mazda dealership) hit 2k.
 
IS your defroster on when your starting it cold??? A/C compressor is a huge load on start-ups TURN IT OFF !!!!! even if u have the heater on in the defrost area your still using the compressor system. Try it both ways let us know.

-Burning smell who knows whats your mileage
 
Last edited:
MITZA said:
IS your defroster on when your starting it cold??? A/C compressor is a huge load on start-ups TURN IT OFF !!!!! even if u have the heater on in the defrost area your still using the compressor system. Try it both ways let us know.

-Burning smell who knows whats your mileage
I had the same problem with the burning smell. It smelled like burning rubber to me. It was so bad the first time I had to roll the window down. The smell was strong. I took it to the dealer and they couldn't find anything. It has happened several times since. I am bringing it back to the garage tomorrow. I'll let you know if I find anything out.
 
wow, let us know on this burning issue, belt?,the motor crank side is on the passenger side of the car, maybe something is leaking slowly and burning on the Exh manifold thats what your smelling or something is stuck in the heater core area. Extremely too many facters to tell what it is over the computer. mmm
 
ufunny2 said:
I had the same problem with the burning smell. It smelled like burning rubber to me. It was so bad the first time I had to roll the window down. The smell was strong. I took it to the dealer and they couldn't find anything. It has happened several times since. I am bringing it back to the garage tomorrow. I'll let you know if I find anything out.
I had a burning smell in mine as well, when I asked the dealer, he said it was something that was sprayed on to protect it during the overseas transport... I still can smell it sometimes, but it is getting weaker and weaker.
 
Joffar said:
I had a burning smell in mine as well, when I asked the dealer, he said it was something that was sprayed on to protect it during the overseas transport... I still can smell it sometimes, but it is getting weaker and weaker.

A weird burning smell up to and sometimes over the first 1k miles is normal. Its a coating to protect the exhaust and engine from the shipping process. Some people say it smells like burning brakes, others say more like tires. But a weird smell similiar to either of these is normal. Atleast for the first 1k or so.
 
B1GHAM said:
A weird burning smell up to and sometimes over the first 1k miles is normal. Its a coating to protect the exhaust and engine from the shipping process. Some people say it smells like burning brakes, others say more like tires. But a weird smell similiar to either of these is normal. Atleast for the first 1k or so.

I have 6000 miles on my CX-7 and have had the smell at least 4 times recently. I had the vehicle in the shop today and they were unable to find anything that could cause the smell. It is very weird and hard to figure out. If anyone else has this problem and finds the reason for it please post it for all to see. Thanks
 

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