2003 Caravan with rear heat.

I have the dreaded coolant smell and foggy windows.

How can I tell if it's the front or rear heater core that is leaking?

Can someone provide the instructions how to replace them? I've searched but haven't found any good directions for this.

Thanks.

Greatly appreciated!

Torinate

 

FRONT HEATER CORE
WARNING: On vehicles equipped with airbags, disable the airbag system before attempting any steering wheel, steering column, or instrument panel component diagnosis or service. Disconnect and isolate the battery negative (ground) cable, then wait two minutes for the airbag system capacitor to discharge before performing further diagnosis or service. This is the only sure way to disable the airbag system. Failure to take the proper precautions could result in accidental airbag deployment and possible personal injury or death.

WARNING: Refer to the applicable warnings and cautions for this system before performing the following operation. Failure to follow the warnings and cautions could result in possible personal injury or death.

Remove the silencer boot fasteners located around the base of the lower steering shaft from the dash panel so that it may be pushed aside.
Remove the brake lamp switch from its mounting bracket.
Disconnect the power brake booster input rod (push rod) from the pin on the brake pedal arm .
If equipped with power adjustable pedals, remove the adjustable pedal assembly.
NOTE: Take the proper precautions to protect the carpeting below the heater core from spilled engine coolant and have absorbent toweling readily available to clean up any spills.

Remove the heater core tubes.
Remove the two screws that secure the heater core mounting plate to the HVAC air distribution housing.
If NOT equipped with power adjustable pedals, pull the accelerator pedal upward (Accelerator Pedal) and push the brake pedal downward (Brake Pedal) for clearance to remove the heater core from the air distribution housing.
Remove the heater core by carefully pulling it straight out of the side of the air distribution housing.

 

Thanks!

Is there a rear heater core as well? How can I tell which one is leaking? How do I change that one?

Thanks again.

 

If you have the rear heat unit, there will be a heater core inside the rear cargo area wall on the passenger side of the van. Easiest way to figure out which one is leaking is stick your nose into the vents of the front and then the rear unit. It's a sickly sweet smell. Frankly, if it's a heater core leak, you should have a noticeable film on the front windshield. It should start appearing on the front windshield first and work its way backward.

 

Yes. I have the rear heat. I can't tell which one is leaking though. I can smell it all in the van. Not really a difference in odour between them.
Yes, my windows get foggy. Mostly noticeable in the side ones more so than the front.

Wish there was an easier way to tell.

Thanks.

 

If you have access to a coolant pressure tester, you can pressurize the system and try to listen for the leak under the dash or at the rear. If you have that much coolant leaking throughout, I'd think you would see it on the floor in the carpet. You could always detail the interior glass and really ventilate the vehicle, and then start over... let the vehicle warm up, and watch and smell the front dash area to see if you can see the vapour coming up from the dash.

I'm just assuming that you've had a good look around, but if it were me, I'd take the time to remove the trim panels on the rear unit because they are easily accessed, and pull up the carpet. I'd then look for signs of any coolant. Also, have you looked up from underneath the vehicle at that rear heater unit? The coolant lines follow along the passenger side of the vehicle near the rocker panel. Do you see any coolant leakage where the lines go up into the interior? There is always the possibility that if its a leak at the rear of the vehicle, it may not be the heater core but instead a hose/line.

More often than not, if its actually a heater core that's leaking, from what I understand, it's usuallly the one in the front. You'll either have to find that pressure tester or start disassembling things if you can't smell it.

 

I'm sorry, I read you said rear. But when I was getting the information, I was thinking front. At least you know what do on the front.

REAR
REMOVAL
WARNING: REFER TO THE APPLICABLE WARNINGS AND CAUTIONS FOR THIS SYSTEM BEFORE PERFORMING THE FOLLOWING OPERATION.

Drain the engine cooling system.
Remove the right quarter trim panel and right D-pillar trim panel from the quarter inner panel.
Remove the rear heater distribution duct from the right quarter inner panel.
Remove the screw that secures the back of the rear heater-A/C unit housing to the right D-pillar.
Remove the screw that secures the front of the rear heater-A/C unit housing to the right quarter inner panel.
Take the proper precautions to protect the carpeting below the rear heater core from spilled engine coolant and have absorbent toweling readily available to mop up any spills.
Disconnect the heater hoses at the rear heater core.
Install plugs in, or tape over the opened heater core fittings and both heater hoses (Heater Core).
Use absorbent toweling to clean up any engine coolant spills from the preceding operation.
Release the four latch tabs that secure the heater core in the rear heater-A/C unit housing.
Carefully pull the heater core straight out of the rear heater-A/C unit housing.
Use absorbent toweling to clean up any engine coolant spills from the preceding operation.

 

Excellent!

Thank you very much for the help. I really appreciate it!

Guess I'll stat pulling carpet and panels and see what I find.