Overheating - possible heater core...

[salvicrashdrive]

Hello everyone,

I have an '00 V6 LS and here's the issue. It overheats after about 20-30 minutes of driving, but faster when I have the AC on. I previously had a crack in the degas bottle and a broken radiator manifold so I replaced them both along with the t-stat and housing. Afterward I bled and serviced the system. I cleaned all debris from the radiator, inspected for leaks, and verified that the hydraulic fan was working.
Now I've noticed that right before the car is going to overheat I get a very noticeable coolant smell through the vents.
After reading the other overheating posts I've come to the conclusion that the most probable cause is the heater core but I have a couple of questions.

1) Besides the coolant smell through the vents my ac and heater work just fine, so I'm not sure if the heater core could be bad despite this.
2) Step 12 of the cooling system draining instructions says the following,
"12. Reopen the heater air bleed to release any entrapped air and close again."

I expected fluid to come out of the heater air bleed as it had in step 10,
"10. Close the heater air bleed when a steady stream of coolant comes from it, during engine idle."
but it didn't, does this confirm something wrong with the heater core.

Thanks..

 

[joegr]

It only confirms that you have air in the cooling system. It seems to be very rare for an LS heater core to fail. I wouldn't replace it just based on suspicion. It is not an easy job to replace. Connect a pressure tester to just the dual heater core and see if it holds pressure for an hour. If it does, then your problem is somewhere else.

 

[lsdarkshadow]

It only confirms that you have air in the cooling system. It seems to be very rare for an LS heater core to fail. I wouldn't replace it just based on suspicion. It is not an easy job to replace. Connect a pressure tester to just the dual heater core and see if it holds pressure for an hour. If it does, then your problem is somewhere else.

+1. I would re-bleed your coolant to check for air.

 

[salvicrashdrive]

Thx guys. I'll go ahead and bleed and service the system again today after work, but one quick one before I do that. On step 12 of the process, should I expect fluid to come out of the heater air bleed? it seems like it should right.

 

[pektel]

Yes. Leave that bleeder open until a steady stream of coolant comes out. it should sputter a bit once fluid starts coming out, then go into a steady stream.

 

[tireman]

Just some thoughts

My 01V6 just ate $2000 in a complete fan replacement. The fan pump had a small leak and could not build pressure enough to push the fan at higher speeds. But that's not what I'm writing about. One thing I found, that is hard to figure out is the coolant leaks. Had the same mystery as yours, smelled coolant but no leak found. What it turned out to be was the plastic coolant hose across the front of the engine with the compressed fittings, and all the other hoses running into it. The compressed fittings crack along the seams, letting a few teaspoons of antifreeze out, and the fan dries it up before you notice it. When you look everything seems dry and ok. I imagine it sucks some air each time also. The techs at ford told me this was common.

 

[salvicrashdrive]

Thx for the responses guys. So I did the drain, bled, and refill today again. This time fluid definitely came out during step 12 the way pektel described it. I'll keep you guys posted in a couple of days on how my baby is doing. Hopefully this headache will be gone...

 

[salvicrashdrive]

Final update on my LS. After redoing the drain and bleed the car overheated again, so I ended up taking it to the dealer.
My problem turned out to be the hydraulic fan actuator. It all made sense. My car would only overheat when my hydraulic fan was asked to work extra, like when my ac was on, or when the weather was really hot. Otherwise i could drive with the ac off, on a cool day for hours without a glitch. I hope this helps others with similar symptoms.
Oh and by the way, my dealer charged me 150 for the part and 450 for labor (including diagnostic).