Burning rubber smell

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Jdring
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Location: South of Oxford, UK. 87' 230GE SWB Manual, 89' 230GE SWB Auto, 2012 G350Bluetec LWB
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When my G350, 463, is up to temperature and I park up, there is always a smell of hot rubber (outside).

I see nothing rubbing on a tyre, but need to look more.  Does anyone else have this experience?

OldEnglish68
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Re: Burning rubber smell

 

I haven't noticed it yet - but I am surprised to get a clear view of the exhaust at the top/back of the wheel arch.

Perhaps yours is there but running closer to the tyre?

Not claiming ANY tech knowledge or ability here but this is all I could think of!

Good luck with the search.

Best wishes

markhowes
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Re: Burning rubber smell

I too have NO tech knowledge but a couple of thoughts:-

You could try running the G from cold up to temp but not actually driving anywhere. Is there still the burning rubber smell? If so then that would seem to indicate that it is not a tyre friction problem.

Assuming your exhaust tail pipe is on one side and not both then is the smell on that side but not on the other? That might indicate it's an engine/exhaust type problem.

Is the smell only on the side that the exhaust pipework runs (under the drivers footwell/seat? Could part of the heatshield have been damaged/fallen off so the paintwork/rustproofing is getting too hot there? If it is under the driver's footwell then is the footwell itself getting too hot - the underneath of the carpet is rubbery?

I'm sure someone who knows what they're talking about will be along shortly with much better suggestions.

 

markhowes
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Re: Burning rubber smell

Another thought - you can get clever little infrared thermometers which are pretty accurate. Just point it at what you want to measure and the temp appears on the little screen.

When you've been on a run and have the burning smell you could check temps of different parts of the car and see if anywhere is much hotter than you think it should be (much hotter than the corresponding part on the other side of the car).

Jdring
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Location: South of Oxford, UK. 87' 230GE SWB Manual, 89' 230GE SWB Auto, 2012 G350Bluetec LWB
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Re: Burning rubber smell

Thanks for the tips.

I can add the smell is external.  I need to park up on a dry tarmac area and slide under to have a sniff/look, and where I can get around it. I originally assumed it was if I had caned it on the motorway, but I don't really do that and its anytime after the engine is warmed up.  I will have a look this week.

bigblock
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Re: Burning rubber smell

Next time you park up it might be worth cheking the wheels to see if  one is  excessively hot a sure sign of a sticking brake calliper. The handbrake linkage is also prone to sticking because most people with autos just use park and dont apply the handbrake.

If the brake calliper pistons are not fully retracting it can cause significant heat build up with the pads rubbing on the disc without you being aware of any issue with the brakes.

markhowes
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Re: Burning rubber smell

Ah yes - the only time my handbrake is applied is when it's in for a service or MOT.blush

Jdring
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Location: South of Oxford, UK. 87' 230GE SWB Manual, 89' 230GE SWB Auto, 2012 G350Bluetec LWB
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Re: Burning rubber smell

Update.  Now I dont smell the burning smell recently.  Even after a 2 hr blast on the motorway.  So I was thinking this might be related to Diesel Particulate Filter (DPF) regeneration.

Other diesel vehicles types report this same symptom. e.g. https://www.civinfo.com/threads/dpf-odd-smell-while-regeneration.21255/ 

Does anyone know if COMAND or CEL lights should show when regen is happening?  Or how often. Or if there is a log of it.

Also my NOX/Ad Blue warning light stopped for a while, and came back yesterday.  That check is probably not done while regen is occurring.  Not sure how long regen takes?  Probably as long as it needs based on pre and post exhaust pressure sensing.

These are not 460 issues!!

LEONIDAS
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Re: Burning rubber smell

 As far as I know the only contact of the exhaust to any rubber component is through the exhaust hangers which  are secured to vibration rubber absorbers. Failing this, might be  worth to check  that the heat shields are intact and the exhaust heat is not getting  absorbed by the underbody sealant. Another possibility might be to check  in the vicinity of the downpipes which are within the hottest part of the sysrem close to the bulkhead insulation.

Jambo
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Re: Burning rubber smell

Another place worth looking is at the engine mounts. On my 606 the exhaust ran quite close to the engine mount and the het shield had broken off exposing the rubber o the hot exhaus giving a rubber smell.