Melted Crayon Smell from Heater Vents
12-19-2013, 09:55 AM
#1
Melted Crayon Smell from Heater Vents
With the recent cold weather, I've been running my heater quite a bit and, for the last few weeks, there has been a fairly strong melted crayon smell eminating from the vents. I did search MBWorld and other sites thoroughly to find many reports of such a smell but have not found a conclusive source. The most common culprit reported seems to be some kind of adhesive under the interior carpet but I am most certain that is not the cause, due to the following conditions:
-Smell strongest with heat on high and driving around town (stop/start)
-Very little smell on the highway but comes on as soon as I exit highway and slow down
-(here's the interesting part) Smell goes away completely when on Defrost!
Due to the Defrost taking the smell away, I've tried the following:
- Run A/C compressor with heater on...smell still there but possibly not as strong...
- Run just top vents to emulate Defrost and possibly focus on dash/foot vents...smell still there
-Run vents on cool and the smell goes away (but I freeze)
Question is...what is so different about the Defrost as opposed to running the heater??
I thought about recirc so maybe the cabin air filter being the problem, but my understanding is that Defrost does not use recirc but rather pulls air from outside.
I'm going to replace the cabin air filter regardless, because it is overdue, but I have little hope that'll solve the problem.
There has to be a simple solution that you MBZ experts will undoubtedly direct me towards, causing me to hoist a celebratory pint in all of your honors!
-Smell strongest with heat on high and driving around town (stop/start)
-Very little smell on the highway but comes on as soon as I exit highway and slow down
-(here's the interesting part) Smell goes away completely when on Defrost!
Due to the Defrost taking the smell away, I've tried the following:
- Run A/C compressor with heater on...smell still there but possibly not as strong...
- Run just top vents to emulate Defrost and possibly focus on dash/foot vents...smell still there
-Run vents on cool and the smell goes away (but I freeze)
Question is...what is so different about the Defrost as opposed to running the heater??
I thought about recirc so maybe the cabin air filter being the problem, but my understanding is that Defrost does not use recirc but rather pulls air from outside.
I'm going to replace the cabin air filter regardless, because it is overdue, but I have little hope that'll solve the problem.
There has to be a simple solution that you MBZ experts will undoubtedly direct me towards, causing me to hoist a celebratory pint in all of your honors!
12-21-2013, 11:42 AM
#2
Out Of Control!!
Quote---Question is...what is so different about the Defrost as opposed to running the heater??Unquote---rather strange question, however when in defrost the temp and blower speed go to max and all other flaps xcept defrost are closed!!----when heating the defrost flaps close and you can direct the flow of warm air to locations desired!!
