I'm guessing I'm due for a heater core replacement, but before starting to rip my dash apart, I would like to see if anyone think it's something else going on. Here are the symptoms I'm experiencing.

1. A few months ago it started to smell like "maple syrup" when running the heater.


2. There is an intermittent coolant leak. When leaking I can see coolant coming out in the wheel well on the passenger side.


3. Vapor/smoke sometimes comes out of the center vent when fan is off.


4. When extremely humid my windows fog up when running the air/heat.


Thanks

 

heater core

 

Only thing not pointing to heater core is the leak? The leak is exterior, not really sure where it is originating from though.

 

It sounds like a heater core, due to what you noted is happening inside the vehicle. Unfortunately, you may also have another leak in the lines. If possible, try and park the vehicle in an area where you can monitor any leaks, such as a garage or place cardboard under it, so that you can try and locate where the leak is coming from. Of course, many auto parts suppliers say that any coolant line is suspect after four years.

The heater core is a big job. If you have not seen them, there are a number of videos on youtube showing how to do it. I am not sure what year your Suburban is.

Good luck with your repair.

 

Sorry, it's a 2000 Suburban 175k miles.

 

+3 for heater core.

 

Definitely heater core.

 

I don't understand why you have not noticed any coolant leakage on the r/side floor & carpet, which there should be since the heater core is directly behind glove box. I would make sure before taking on a big repair like this. There are several connections on both heater hose's before entering the firewall, which is close to r/side wheel well. JMO, Good luck.
David g.

 

sometimes you don not see a leak on the floor as the coolant collects in the heater box.