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Burning Rubber Smell when Accelerating

6K views 21 replies 8 participants last post by  verrilli 
#1 ·
Hi All,
I have a burning rubber smell that comes strong inside the car for a short period of time, only when accelerating. I was thinking clutch slipping but I'm not sensing any slippage. I tried pulling parking brake on and letting out clutch with some revs and the car pulls steadily through the parking brake. I also looked for other culprits - the front flex joint is intact with just a small crack. Belts are tight.
Are there any other tests I can do on the clutch? Or other suspects?

Colin in Apex
 
#6 · (Edited)
"Colin Verrilli"

The Colin Verrilli of the 164 Digest? Really miss that web site, always used it for older information. Granted, it no longer got any inquiry action as in the old days before the BB, don't know why, but was still a great source for earlier problem information and solutions from back when the 164s were being sold.
 
#9 ·
My Milano Verde has the same symptom (burning rubber smell upon hard acceleration) -- I had this paranoid fear that somehow the timing belt was the culprit, so I'm actually relieved to read that it's probably a giubo rubbing due to excessive motor or driveshaft lateral movement. Less tragic!
 
#10 ·
Colin, it was nicely done and very comprehensive. Too bad it wasn't attached to the BB 164 section as a 'sticky'? It seems that much of what we discuss these days was already covered in the Digest.
 
#12 ·
I know the smell (last Milano). The interesting part is that it only happens when you "sink spur". So if rubber pieces of Giubo fell off & melting on the exhaust, I would expect they would continue to give off smell regardless of where accelerator pedal is.

I would find a secluded spot or secondary road and stomp on it. (bring some good gloves) Pull over and look for smoke or try to isolate which end it's coming from (with the schnoz). Also, check the exhaust hangars. There's only so much rubber near a heat source and the smell is distinctive. Exhaust hangars (esp, the "O" one's) wear out faster than most everything else on the suspect list.

Let us know if you locate the the stinker...
 
#13 ·
Here are a couple of threads from 2008 & 2010 that might be helpful. The Spruell one turned-out to be the timing belt!

http://www.alfabb.com/bb/forums/milano-75-1985-1993/173971-burnt-rubber-odor-high-revs.html

http://www.alfabb.com/bb/forums/milano-75-1985-1993/129036-timing-belt-burning-rubber.html

Hope this helps,

Esp. because it's hard to have a V6 Alfa and not sink spur, and more importantly, that smell is rather ghastly. Which then becomes a "negative feedback loop" where one should not exist! Lol
 
#14 ·
Here are a couple of threads from 2008 & 2010 that might be helpful. The Spruell one turned-out to be the timing belt!

That 2nd one's interesting. Coincidentally, I noticed that my right timing belt cover was brittle and it even broke when I touched it. I took both covers off and checked the tensioner position after rotating to TDC. It was ok. I didn't notice any wear on the timing belt or on the cover so I dismissed it as just rotting plastic.
I replaced the cover with a new one and re-assembled. I haven't taken it for a test drive yet.
 
#16 · (Edited)
I think on that Spruell post, what he was saying was that the belt had "walked" to the edge too far and was contacting the block down below at the crankshaft sprocket.

Something I noticed whenever I changed a timing belt is that if I lined it up perfectly in the middle of the cam sprockets as I strung the belt around, that it would inevitably walk into it's "bedded" position after the obligatory few manual rotations of crank. See how it's off center? This is normal as long as the belt is not riding off the edge.
Vehicle Engine Auto part Car Automotive engine part


I can't imagine how he located the spot where it was rubbing, but something to think about. If the belt is way on the edge, you may want to remove the covers and shine a flashlight down there.

This pic is of my motor in 2008 just before timing belt/water pump replacement I think. Covers off. This GTV6 became my daily driver between summer 2008 and fall 2011 when my work commute became 50 minutes.
 
#17 ·
If the timing belt is the culprit, why only under hard acceleration? My bet is the guibo. Under acceleration the flex disc is being deformed, both stretched and compressed and spinning at engine RPM. That deformity can generate a lot of heat just like tires do while driving on the highway. They don't have to look cracked to be deforming. Small defects in the rubber where it is melded to the steel bolt holes will begin to rub against itself and cause more heat. I had that rubber smell under similar circumstances and exploded a guibo not too long after. That's my theory anyway.
 
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