View Full Version : Water in Rear Heat Exchanger??

05-18-2015, 07:56 PM
Hello, I have a 2004 158 passenger van 90K miles. I've only had it for about a month, so I'm still getting to know the vehicle. One day not long ago I mistakenly activated the auxiliary heater while driving. At the end of that trip I noticed a few drips of "water" from the plastic heat exchanger box under the vehicle and behind the driver seat. I assumed it was just some condensation because the auxiliary heater was running.

Yesterday after a short drive I notice a bit of liquid on the floor of the interior of the van. Right next to there rear floor heat vents. Today I removed the rear heat rail and discovered standing water in the rear heat exchanger box. At frist I though maybe it was coolant, but the vehicle isn't low in coolant and I checked the specific gravity of the fluid and it appears to be water.

Can anyone guess as to where this water may have come from? Any advice is much appreciated.
Thanks in advance


05-19-2015, 12:38 AM
You probably have a roof leak around the exterior portion of the unit.
Condensation from the outer unit (or rain water) is leaking into the interior.
There's a good thread somewhere here that describes what you need to do to seal it back up.