Smells like burning plastic

bbarggren · 03-03-2021, 12:48 PM

Looking for some help with my 2015 328i GT xdrive. For the past week, there has been an occasional smell like melting wax and burning plastic/rubber. I did the first logical thing by replacing the drive/serpentine belt last night. The car has 80K miles on it, so it was due for a belt anyway. Still stinks. I took off the engine cover and the thick foam layer underneath it expecting to find something melting....no dice. I saw a puff of smoke at idle from the passenger side and it looks like SOMETHING is leaking and dripping on the exhaust. I'm 99% sure it's not fuel as I would smell gas under the hood and my car would be on fire. I did replace the high pressure fuel pump a few moths ago but it looks OK.

What's dripping on the exhaust?!?!?!?!

It's hard to pinpoint because it only happens maybe once every 5-10 minutes.

Billfitz · 03-03-2021, 01:09 PM

The most likely culprit is oil. Trace it with UV dye.

bbarggren · 03-04-2021, 10:06 PM

It is indeed oil. I found the spot and used a piece of white paper on a long stick and waited for a drip. Oil dripping directly on to the exhaust. Head gasket?? At 80k miles?

Billfitz · 03-05-2021, 07:35 AM

Head gasket not likely. Valve cover gasket very likely. That's why you need to trace it with UV dye, to see the exact spot of the seepage.

bbarggren · 03-05-2021, 10:17 AM

That will be cheaper than a head gasket. If that is the culprit, I may keep the car.....would have sold it if it was a head gasket. I'll get the dye today. Thanks for the reality check....I should have thought of the valve cover.

Billfitz · 03-05-2021, 11:57 AM

If it is the valve cover gasket search out recommendations on replacing the valve cover as well.

bbarggren · 03-05-2021, 03:36 PM

I found what appears to be a decent BMW shop in Denver. I'm dropping off the car on Monday and will ask them about that. I turn my own wrenches most of the time, but this is something for a pro.

admranger · 03-05-2021, 06:57 PM

Quote:

Originally Posted by bbarggren

I found what appears to be a decent BMW shop in Denver. I'm dropping off the car on Monday and will ask them about that. I turn my own wrenches most of the time, but this is something for a pro.

BimmerHaus in Broomfield is a good option. I know the owners. Very honest and straightforward people. Happen to have a ton of national championships in autocross between them. They also help those less fortunate out with their time and money. Good people.

bbarggren · 03-11-2021, 10:03 AM

I'll look at BimmerHaus next time around....thanks.

03-03-2021, 12:48 PM	#1
bbarggren New Member 6 Rep 6 Posts Drives: 2015 BMW 328i GT xDrive Join Date: Mar 2021 Location: Dillon CO iTrader: (0)	Smells like burning plastic Looking for some help with my 2015 328i GT xdrive. For the past week, there has been an occasional smell like melting wax and burning plastic/rubber. I did the first logical thing by replacing the drive/serpentine belt last night. The car has 80K miles on it, so it was due for a belt anyway. Still stinks. I took off the engine cover and the thick foam layer underneath it expecting to find something melting....no dice. I saw a puff of smoke at idle from the passenger side and it looks like SOMETHING is leaking and dripping on the exhaust. I'm 99% sure it's not fuel as I would smell gas under the hood and my car would be on fire. I did replace the high pressure fuel pump a few moths ago but it looks OK. What's dripping on the exhaust?!?!?!?! It's hard to pinpoint because it only happens maybe once every 5-10 minutes.
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03-03-2021, 01:09 PM	#2
Billfitz Lieutenant General 4961 Rep 10,898 Posts Drives: '15 328iX GT Join Date: Jan 2015 Location: New Hampshire iTrader: (0)	The most likely culprit is oil. Trace it with UV dye.
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03-04-2021, 10:06 PM	#3
bbarggren New Member 6 Rep 6 Posts Drives: 2015 BMW 328i GT xDrive Join Date: Mar 2021 Location: Dillon CO iTrader: (0)	It is indeed oil. I found the spot and used a piece of white paper on a long stick and waited for a drip. Oil dripping directly on to the exhaust. Head gasket?? At 80k miles?
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03-05-2021, 07:35 AM	#4
Billfitz Lieutenant General 4961 Rep 10,898 Posts Drives: '15 328iX GT Join Date: Jan 2015 Location: New Hampshire iTrader: (0)	Head gasket not likely. Valve cover gasket very likely. That's why you need to trace it with UV dye, to see the exact spot of the seepage.
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03-05-2021, 10:17 AM	#5
bbarggren New Member 6 Rep 6 Posts Drives: 2015 BMW 328i GT xDrive Join Date: Mar 2021 Location: Dillon CO iTrader: (0)	That will be cheaper than a head gasket. If that is the culprit, I may keep the car.....would have sold it if it was a head gasket. I'll get the dye today. Thanks for the reality check....I should have thought of the valve cover.
	Appreciate 0 Quote

03-05-2021, 11:57 AM	#6
Billfitz Lieutenant General 4961 Rep 10,898 Posts Drives: '15 328iX GT Join Date: Jan 2015 Location: New Hampshire iTrader: (0)	If it is the valve cover gasket search out recommendations on replacing the valve cover as well.
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03-05-2021, 03:36 PM	#7
bbarggren New Member 6 Rep 6 Posts Drives: 2015 BMW 328i GT xDrive Join Date: Mar 2021 Location: Dillon CO iTrader: (0)	I found what appears to be a decent BMW shop in Denver. I'm dropping off the car on Monday and will ask them about that. I turn my own wrenches most of the time, but this is something for a pro.
	Appreciate 0 Quote

03-11-2021, 10:03 AM	#9
bbarggren New Member 6 Rep 6 Posts Drives: 2015 BMW 328i GT xDrive Join Date: Mar 2021 Location: Dillon CO iTrader: (0)	I'll look at BimmerHaus next time around....thanks.
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