Here's the problem. Heater in 95 blowing cold air, passenger side carpet soaked, dripping from knee bolster ,coolant level low. My diagnosis, bad heater core. Thanks to Red Dwarf and Angel of Death, I managed to get the old core out. When I removed the bolster, the foam on the back side was soaked. When I opened the heater box, it was somewhat wet, but no water running out. For giggles, I submerged the old core in a bucket of water, held my thumb over one port and blew compressed air into the other. No bubbles, air tight, Oh ****. I just spent three nights after work tearing this thing apart.

So, were the symptoms all just coincidences that led me to miss diagnose the problem? Such as, no heat because, the flapper in the heater box isn't working, some how water got in from the heavy rains we've been having and the coolant happened to be a little low (in between the hot and cold marks, when the engine was hot).

I probably didn't investigate the wet carpet enough. I couldn't tell for sure if it smelled like anti freeze but, blamed it on my nose being stuffed up. It did feel a little oily. I should have used a white rag to blot it up and see if it looked green.

Now I'm done kicking my self in the ***, how about some thoughts or suggestions or condolences.

Thanks, Grinder

 

I would guess the same thing as you did. I cant see GM building the car and having the possibility of rain water getting into the car from one of the climate control vents.... Now that youve gotten into it, I would change the heater core anyway.

 

My heater core did the same thing. It had a very small hole. When I put the new one in, it stopped leaking.

 

Serves as a reminder to check those small cowl chamber drain tubes, doesn't it? Easy to get them plugged up, at which point you get water in thru the air control door...

That's not going to get the Bolster/pad wet, though - A-pillar weatherstrip issues will do that...

 

Putting a heater core in a C4 is truly a PITA.

If it is your HC, do yourself a favor if doing it yourself and remove the passenger seat before you get started.

I'm sure others will agree that the entire car must have been built around the heater core.

 

Ouch! You have my sympathy.

 

Remember the core will be under pressure when operating in your car, so your water test will not be conclusive,,,all that water in your car points to the heater core leaking, but did your car smell of anti freeze , or have a damp screen by the air vents which would indicate heater core leaking...keep us posted.....

 

Well, figured it out. The condensation drain, for the ac, was plugged up and the condensation was running into the heat exchange box (the box the heater core is in). I could see the water level in the box had been about an inch deep, at one point. The water drained into the motor/gear box for the vent flapper ( what's that thing called, anyway and where can I get one?) The gear box was full of water and the motor, seized up, explaining why I had no heat, the flapper was set for ac. It's a hard learned lesson.

On the bright side, I would have had to tear into the dash, anyway. Since I already bought a new heater core, I'm going to replace the old one. I also need the motor/gear box for the flapper door. Anything else that would make sense to replace, since the dash is already ripped open?


Thanks for the replies, Grinder

 

...ya found the answer before i had a chance to post it!...had that problem in an earlier year car and my friend had it in his van 4 weeks ago...glad ya got it fixed though!