Acrid smell when car gets hot

[maddog1982]

Bit of a weird one this! When the cars hot and its wet outside I notice an acrid smell when I come to a stop and open my door. Its almost a plastic/ rubber smell. I've recently put a full borla touring on her and done a good 1000 miles. Im sure I could smell it nearside front wheel getting close up to it. Car was serviced 5000 miles a go and is bang on the level for oil and the colour is golden brown too. Only other mods are four MPS4s and a steeda clutch spring. Clutch comes right up to the top and never slips either. Also thought it maybe brakes, they are def not stuck on but I find the power of them doesnt seem as good when I've driven the car for half hour or more which seems weird!!

Sponsored

 

[aleccolin]

Does it have the PP brakes? If so, get that checked out, because they generally don't falter even under track use. Could be something with the parking brake maybe.

My exhaust make some "new exhaust" smells for a while, but not 1000 miles worth.

 

[maddog1982]

Thanks for the reply!
It does indeed, I believe our uk GT cars only ever came with these. Massive 6 piston brembos. Does see. To pull you up hard when you step on them but it's like after driving for a while you have to press the pedal harder. They seen far far more sensitive and powerful when the car is cold. I've got it boomed in with a specialist in 3 weeks time so I will mention this to him. Oh the brakes squeal like a stuck pug also!

 

[aleccolin]

I missed the part about it only smelling funny when wet out...now I'm really not sure.

FWIW I drove my truck through a flooded area to rescue some people once and I think some sort of critter got stuck in my undercarriage, stank like hell any time I drove in the rain for about 2 months after that.

But that's probably not your problem lol

 

[Entai]

Thanks for the reply!
It does indeed, I believe our uk GT cars only ever came with these. Massive 6 piston brembos. Does see. To pull you up hard when you step on them but it's like after driving for a while you have to press the pedal harder. They seen far far more sensitive and powerful when the car is cold. I've got it boomed in with a specialist in 3 weeks time so I will mention this to him. Oh the brakes squeal like a stuck pug also!

It sounds to me, very much like a slightly stuck caliper.
The combination of brakes squealing, acrid smell, and braking performance dropping off after a while of driving all point to pads not being allowed to back away from the disc enough, and therefore heating up due to excess friction between pad and disc.

Calipers and pads need stripping down, the slides on the caliper cleaning up and high temp grease applied, should sort out all your issues.

I stripped mine all down within the first 50 miles of having my car, to check them all out, and found, on mine at least, zero grease on any of the components, quite typical of most manufacturers in my experience.

 

[maddog1982]

It sounds to me, very much like a slightly stuck caliper.
The combination of brakes squealing, acrid smell, and braking performance dropping off after a while of driving all point to pads not being allowed to back away from the disc enough, and therefore heating up due to excess friction between pad and disc.

Calipers and pads need stripping down, the slides on the caliper cleaning up and high temp grease applied, should sort out all your issues.

I stripped mine all down within the first 50 miles of having my car, to check them all out, and found, on mine at least, zero grease on any of the components, quite typical of most manufacturers in my experience.

Thank you ! It really does thinking it though. After say 30 mins of driving its like I am having apply 4 or 5 times the presure on the pedal to get it to pull up, pedal just feels weird. if this is the case, will it need new pads? The tyre wasn't baking hot, didnt dare touch the caliper, nothing was glowing though. Car does roll if you push clutch in on a slight incline too. Noticed my fuel econonmy has dropped 2 or so mpg but I put this down to the cold weather. Ill see if I can get it in the workshop this weekend

 

[Symone]

Thank you ! It really does thinking it though. After say 30 mins of driving its like I am having apply 4 or 5 times the presure on the pedal to get it to pull up, pedal just feels weird. if this is the case, will it need new pads? The tyre wasn't baking hot, didnt dare touch the caliper, nothing was glowing though. Car does roll if you push clutch in on a slight incline too. Noticed my fuel econonmy has dropped 2 or so mpg but I put this down to the cold weather. Ill see if I can get it in the workshop this weekend

Mine always had a smell after driving fairly quickly, I believe it was the underseal that was sprayed onto exhaust , did it from day 1 until I sold it 18 months later

 

[Alfa Male]

If the brakes are binding slightly you should see an excess of brake dust build up on a wheel. Also the wheel will probably be hotter to the touch than other wheels too.

As for hitting a dead animal, I had the misfortune to run over an already partially squashed (dead) badger in the middle of the road on a long journey last month in the old car.

Oh my god, the smell of burnt badger was making me physically sick and my eyes stream. Even with internal circulation on the vents this was still not stopping the acrid smell. Spent most of the journey with my head out the window until I could locate a jet wash to remove the said badge !

 

[maddog1982]

They do seem very dusty and creek when I move off as I set off. I also can here a faint rubbing sound when going slow with the windows down. Booked into demon performance centre to have a look for me.

 

[Count Drunkula]

I was interested to read this. Mine has done it twice over the last two years, but not necessarily when wet. Once the smell was quite strong, The other time less so. The car is working fine and the garage couldn't find any issue with it, brakes or otherwise. So a bit of a mystery, but I've stopped worrying about it now. It seems I'm not alone, this and a few other threads seem to indicate quite a few of the cars do it, generally in a random fashion.

https://www.mustang6g.com/forums/threads/burning-rubber-smell-in-the-cabin.96632/

 

[maddog1982]

So I checked the oil and its bang on full and golden brown, done 5k miles since it was serviced last March. Cant see any leaks but once it's on the lift it will make life easier. What I did clock though is my engine has blanks where some valve cover bolts should be. It doesnt appear to be leaking but I found this thread with a TSB. Do we UK guys get the 5 year 60k warranty as it's the drive train? My 3 year warranty ran out last Oct. https://www.mustang6g.com/forums/threads/check-your-valve-cover-bolts.22476/page-1

 

[Count Drunkula]

So I checked the oil and its bang on full and golden brown, done 5k miles since it was serviced last March. Cant see any leaks but once it's on the lift it will make life easier. What I did clock though is my engine has blanks where some valve cover bolts should be. It doesnt appear to be leaking but I found this thread with a TSB. Do we UK guys get the 5 year 60k warranty as it's the drive train? My 3 year warranty ran out last Oct. https://www.mustang6g.com/forums/threads/check-your-valve-cover-bolts.22476/page-1

That's interesting. Although the smell I've had smells more like rubber than oil. Also never any smoke and no oil under the vehicle, but I'll have a look just to be sure.

 

[maddog1982]

So had the car thoughly checked over by Demon Performance and everything looked spot on. No leaks at all, brakes are not sticking on. He said the smell could be the exhaust as its still new. The only issue he could see was the disks are slightly warped and have a lip of rust. This would explain the squeeling, He wonders if the brakes are grabbing this and then after I have run it for a bit its polished up so in essence it has less friction so less bite. Now I told Ford they were warped when it went in earlier this year and they said no they aint its your wheel bearing! So, the car is now out of warranty so I will replace the front brakes and pads and go from there. Do people stay standard or should I through some say Ferodo DS2500 pads on her?

 

[maddog1982]

So the smell seems to have gone! Must have been the new Borla system. Im at a loss what discs and pads to buy though. Looked at EBC grooved and Yellowstuff or maybe EBC discs and standard pads.

 

[Benno2000]

Good news on the pong gone

You know that this is my idea of brake porn.......

Stoptech rotors with Ferodo pads on front and Ford pads on rear.

Although I’d happily have fitted the Ford Performance kit if it had been a wee bit cheaper, lol.

Benno

Sponsored