Reese05923

Hi all, I recently bought my 1993 c4 about two months ago and now it just blows hot air and will fog up my windshield. I took it to Firestone and they said my condenser is leaking and they want $1100 to fix it. It sounds to me like a bad heater core but there’s no coolant on the ground or floorboard. Is there any way to tell if the heater core is bad other than by taking the time to tear the dash apart? I also plan on putting dye on the condenser tomorrow to see if it’s really leaking.

DWAVette

What makes you think it is a bad heater core? Is there coolant leaking on the floor board? Are you losing coolant from your engine?

Does your air conditioner work properly and blow cold air from the dash vents? If you have a bad leak in the ac condenser, your ac will not cool.

Put your defrost on and turn the temperature all the way down and see if the air coming out gets cold.

I am not saying your mechanic is correct or incorrect. However, check those two systems individually first then come back here.

Oklahoma Adam

Sounds like a heater core to me. You could have a small leak that is causing it to fog up but not leaking onto the carpet yet. Coolant has a distinctive smell and taste. Might give the fog on the windows the ol' taste test.

Reese05923

Yea the ac does not blow any cold air at all. I may have misworded it but I’m not saying it’s one or the other, it could be both. I'm suspecting a heating core also because of the smoke coming from the vents because I’m not sure what else it could be and that seems to be the majority opinion on these forums. However there is no coolant leak and a steady amount in the reservoir.

DWAVette

If your ac needs a new condenser, they can be pricey - few hundred bucks. I have redone a few systems so I can see your mechanic needing some hours to do the job: change the condenser, you will need a new dryer, need to evacuate the system (takes time), and then recharge. Of course, any savvy businessman always adds on a little for the warranty work to come. I don’t know labor rates in your area but they are running close to a hundred an hour by me.

I hear the heater core change can be a time consuming process.

Do you trust your mechanic? Have a solid relationship?

'78CorvetteS.A.

Pressure test the cooling system, should hold indefinitely after air moves around and needle settles. Also wipe the fog off of the inside of the windshield with a fresh paper towel, note color and smell (do not taste it)....most likely heater core. Finally assuming there isn't too much residual coolant in the heater core housing, you could bypass the heater core all together and run the fan....does it stop fogging up? I'd put something down on the floorboard/carpet before any tests or running it any longer....eventually it will make it to the carpet and you don't want to have to pull the carpet for cleaning on top of every else! I'd start with a pressure test, good luck👍
Edit: you could unhook the heater hoses and loop them together with a homemade valve stem and pressurize just the heater core......see if it leaks!

Whaleman

OP, Do you mean the condenser up front or the evaporator coil? Dan