I'm sure someone here knows what the problem is. Let me give you all some details...

My dad bought his blazer in may of this year. It's a 1999 with the 4.3. We have ran the A/C the last couple times we have taken it out, and it was blowing pretty cold and everything seemed to be fine. He has a dog, so he left the A/C on while he ran into the convenient store. When he returned to the vehicle he said there was a puddle of coolant below the vehicle, and that the car was overheating. He only lives about an 8th of a mile from the store so he turned the A/C off, and drove the car back to the house. He says there was steam coming through the vents before he turned the A/C off, which stopped as soon as he turned the A/C off. When he got it home I went over to look at it,there was a significant amount of water by the passengers side front wheel. Any idea if that would be the heater core, or intake gaskets? I'm not sure where to begin with this problem so I figured I'd come on here and see if i couldnt get some tips,hints, or hacks that will make my life a little easier. Lol. For now I loaned him my 2000 Chevy Blazer to drive until I can get his running properly again. But I could definitely use some tips to get the problem rectified as soon as possible. Thanks

-Chris

 

First and foremost that is where the A/C condensation drain is and on a humid day a lot of water will pour out there. Not to say that a heater core couldn't be a possibility but I'd check and make sure it's not just good, clean water draining out first.

 

I agree it sounds like the liquid you say was likely condensation.

The overheating could be due to a combination if it being a hot day, the extra load due to thr AC being on, and poor cooling by the radiator and fan.

The first two cannot be changed but the cooli g system can be checked.

I'd check if the radiator fins are blocked. Also be sure the fan shroud is intact, that the fan clutch is working and that the fan is working when idling.

 

It was definitely coolant, so I just done a bypass on the heater core lines and everything seems to be fine now.

Thank you!!

 

Well...I guess you know that someone has a job to do before winter hits. How hard is a heater core to replace on these things?

 

From what I've seen on youtube and some other places, it seems like the only P.I.T.A is really taking the dashboard out. The heater core is located under the dash almost directly in the middle of the cab. You can probably change it out in 2 hours or so. But my dad is 60 years old, retired veteran, and disabled. I cant really find the time to do it because I have wife and kids etc, and the only days I have off he seems to have doctors appointments and such. I'll get around to it before winter hits I'm sure. I live in NC where winter never really comes... it does but it doesnt get THAT cold here. Luckily I dont live up North somewhere. Haha

 

It is a MASSIVE p.i.t.a... I've done a heater core job, and I've also swapped out my dash to change colors, both are hrs filled jobs...

 

If it overheated, bypassing the heater core did not fix anything. Its not used in AC mode.

If it was, there wouldn't be any AC.

Sounds like a plugged radiator