Using coolant

[Zorba]

Still trying to determine what's up with my cooling system - if anything. Heater core stinks when hot. No visible drippage therefrom. Coolant level in puke bottle is dropping - about 1/2 inch over 100 miles. Cooling system pressure tested twice and passed both times. I think the heater core is seeping slowly. Next test is to bypass it and see if the fluid drop stops.

Any other thoughts?

 

[CodaMan]

I agree. Bypass the heater core and see how it goes.

 

[Nightmare9]

I'm STILL flushing my system.
I'd bypass the core and see if it stops.
My neighbor had a bad core in his Jeep and it was something like $500-700 to fix it. You need to remove a HUGE section of the dashboard. Once they started they found most of the vacuum 'motors' were bad. He had a hell of a time finding a good replacement box (complete assembly with all the doors, motors and the core.
GL

 

[Zorba]

I'm STILL flushing my system.
I'd bypass the core and see if it stops.
My neighbor had a bad core in his Jeep and it was something like $500-700 to fix it. You need to remove a HUGE section of the dashboard. Once they started they found most of the vacuum 'motors' were bad. He had a hell of a time finding a good replacement box (complete assembly with all the doors, motors and the core.
GL

Oh I know - the radiator and heater core quality in these vehicles SUCKS, and that's the OEM! Aftermarket is even worse. If I can get it fixed for $500, I'd be *VERY* happy (assuming heater core *is* bad).

 

[AMS417]

I did a heater core a while back in an S10 Blazer. Took me 6 hours to complete it, but saved $800 in shop labor. It's not a difficult job, but it is tedious. I didn't end up with any extra screws, and it didn't leak, so that's a win.

 

[g.hayduke]

I replaced my heater core with a new OEM part in my '05 and the brand new OEM core leaks! It doesn't leak enough to go through replacing it again but if I was going to replace it again, I would probably try to find a quality aftermarket part knowing what I know now. Coolant level drops very slowly and I occasionally smell antifreeze in the cab.

Replacing it is a pretty big job:

1. Have the AC system evacuated.
2. Remove the steering column.
3. Remove the entire dash board
4. Remove the entire HVAC box that lives behind the dash
5. Replace the heater core.
6. Reinstall the HVAC box
7. Reinstall the entire dash
8. Reinstall the steering column
9. Recharge the AC system

 

[Nightmare9]

1981 Ford Mustang
The heater core was right behind the glove box. I think it was 2 screws and 2 hose clamps. 30 min MAX

 

[Flivver250]

If yours is the original, it has lived a good life. I'd replace the evaporator for your AC while you are there (if equipped). No reason not to. My AC was leaking, I replaced the heater core as well. Trust your nose.

 

[AMS417]

1981 Ford Mustang
The heater core was right behind the glove box. I think it was 2 screws and 2 hose clamps. 30 min MAX

Almost as good as my 1972 Karmann Ghia. Basically a lawn tractor with a body on it.

 

[qslim]

When I was fixing Toyotas in the late 90's/early 2000's replacing heater cores & evaporators were pure joys (on most of them). All you had to do was drop the glovebox & pop off a door on the side of the very-accessible HVAC box. There was your heater core. Disconnect the line, slide it out, slide in a new one. Whatever packaging engineer that designed those must have been a former mechanic.

Still trying to determine what's up with my cooling system - if anything. Heater core stinks when hot. No visible drippage therefrom. Coolant level in puke bottle is dropping - about 1/2 inch over 100 miles. Cooling system pressure tested twice and passed both times. I think the heater core is seeping slowly. Next test is to bypass it and see if the fluid drop stops.

Any other thoughts?

I think you're on the right track. Most heater cores I've changed that didn't have a catastrophic failure had little pinhole leaks where the volume of coolant escaping was small enough to evaporate before it could drip - hence the smell. I'd say bypass it & see where you're at.

 

[TurboTJ]

I have a very slow loss of coolant that I have been monitoring. The level in the overflow tank drops maybe 1 inch in 1000 miles. There are no visible leaks and nothing smells, in the cabin or elsewhere. There is no sign of coolant in the oil. It never overheats although the temperature will rise slightly (10 to 15 degrees) above the normal 210F on a long climb. The radiator, pump and hoses are new within the last 10k miles.

Do you think I have trouble brewing or is this entirely normal?

 

[dbbd1]

No, it's not normal.

When I had a coolant leak, it was from a small slit (where it pushed onto the barb) in the tubing going from the radiator overflow to the coolant reservoir. There was just a small particulate trail on top of the radiator.

Message being- it could be anywhere. Is it time to start worrying about it? That's up to you. If you don't mind monitoring it, go for it. And, just always be watchful of smells and puddles.

Your next step, if you are so inclined, would be a pressure test.

 

[01CuHed]

On my 2001 Sport with original stock heater core I've noticed for some years now...right at first start-up I can get a FAINT smell of antifreeze from time to time in the cabin but RARELY ever have to add coolant!? Now since I've said this my passenger floor next week will be full of coolant. Ha!