Bought my truck 2 months ago and just now noticed that there is small dots of oil-ish stuff on the inside of the window. After thinking about it I figure it must be the defrost blowing something on it. Where does the defrost pull its air from? Any ideas?

 

It pulls it from the heater core. Have you noticed your coolant level going down recently? You probably have a hole in your heater core.

-Matt

 

Could also be the ac evaporator (refrigerant carries oil with it when it leaks)
When running the defrost the ac is on to take humidity out.
Is this a diesel? wasn't their a thread about deisel fumes in the cab ?
Wasn't it fumes somehow getting in the cab from the AC/heater plenum.
Just a thought
Rich

 

What year truck, other details?

 

if its coolant, it may smell sweet

 

My sig has info.


late 04 diesel.

No sweet fumes at all, colant has always been at the same level, but have only had truck for 2 months. Though once in a while if I turn the heat **** down into the blue section I can get a brief smell of diesel.

 

How do I look for that?

Also where is the heater core so I can take a look for signs of a leak. Passenger side behind glove box?

 

yes squeeze the sides of the glove box to get it to open further.should be wet around it or on the floor mat under it.
A refigerant leak detector would be the only way ,I think you could test for it.

There is one other thing that we all forgot about and that is the plastic dash panel on all of our trucks tend to "out gas" or release something from the manufacturing process that leaves a oily sticky residue on the dash.
This happens alot in warm climates ,where the truck sits in the sun alot.
Maybe this your problem.
I just use armour all clean wipes and it cleans it right up.

Rich