atomos31909

Ok, this whole question stems from trying to solve an intermittent heat problem in my Acura. The heat gets cold if I sit at idle for to long, i.e, at a light. However, it blows nice and hot once I begin to accelerate.

In trying to resolve this I have replaced the t-stat, and water pump, and have had the heater control valve and heater core checked- both are ok. My mechanic has theorized that it could be a bad head gasket. However, I think he's wrong because:

1) The car doesn't overheat
2) No smoke out of the exhaust
3) Oil is normal
4) Antifreeze is normal
5) car runs at normal temps
6) engine runs smooth and has not lost power.
7) Block test kit (chemical exhaust sniffer) shows no exhaust gas in antifreeze (stayed blue)

Could I still have a bad head gasket despite all of the evidence that its fine? If its not the headgasket, could the heater issue be attributable to a bad radiator, blend door, or perhaps a small external leak i haven't detected?

This weekend I performed a rather thorough air bleed on the cooling system- put the car on an incline, ran it from cold to warm for about an hour, squeezing upper/lower rad. hoses plus the heater core hoses- seemed to burp alot of air when i did that. (bubble followed by a drop in coolant level). Now, the heater problem is only intermittent. Sometimes it acts as its supposed to- it maintains temperature. However, once in a while it still will get cold...

Could I still have a bad head gasket despite all of the evidence that its fine? If its not the headgasket, could the heater issue be attributable to a bad radiator, blend door, or perhaps a small external leak i haven't detected? Or is it likely that there may still be some air pockets (stragglers) that need to be purged out?

dtapia

sounds like you have a air pocket in the heater core. the rl is a tough system to bleed i had a rl that was doing the same thing and i looked and no leaks nor other issues.i bought a mighty vac cooling system tool that puts the system in to a vacuum and then sucks the coolant into the system,i didnt think that was the problem but i tryed it anyways and returned the car to the customer.she emailed back the the service adviser and stated the heater has never worked that well before.so after a month the system is all good now.the system just would not burp the pocket out on its own.we see a few like that but not many.
i would try that and go from their.
here is a link to the tool.
http://buy1.snapon.com/catalog/item....re&dir=catalog

shamal

I have the reverse problem, in a 99. Car runs warm air that then suddenly turns cold. Thank you I'll get it vaccumed, at the dealer? They could not find a problem hence my posting the question elsewhere on this site. thanks for your post!