After warmed up, my 99 RL generates plenty of heat when it's reving at 1,000 rpm or higher (either at a stop or moving), but when it drops to idle (around 750 rpm - usually at a stop), the heater gradually starts blowing cold air. If I'm sitting at a stop and the air gets cold, I can put the car in neutral and rev the engine up to 1,000 rpm or higher and the air get nice and hot.

The colder it is outside, the colder the air it blows...this is especially noticeable (annoying) when the outside temp drops below 30.

This problem began about 18 months ago after a scheduled maintenance in which the engine coolant was flushed. I have taken the car to the dealer for this problem six or seven times. At one point they changed the thermostat (claimed it was not closing)...while the faulty thermostat may have been a contributor to the problem, replacing is didn't fix the problem.

The last time I took the car in, they explained that this was "normal" because the engine is not generating enough pressure to keep the heater coil hot at 750 rpm. I think that's a crock, especially given that the car did not perform this way before the scheduled maintenance referenced above and I find it hard to believe this a performance standard Acura would consider acceptable.

Can anyone shed some light on this one from personal experience or otherwise? Thanks.

 

Ok, I noticed that my 97 RL does the same exact thing. Email me if you get an answer.

 

There might be some air in the cooling system and maybe you need to bleed the system. I'm don't know how to bleed bleed the cooling system.

 

Yeah, its a bunch of crock. Have you had the thermostat and coolant checked?

 

I have the same problem, from my research it sounds like air in the system. I have been told you can bleed it by parking on an up hill grade with the radiator at the highest point. Open the radiator cap after cooled, start the engine, turn on the heater, and let warm up completly, watch for bubbles. I have not had results with this method. There is a bleeder valve on the the top of the thermostat housing. With the engine warm, heater on, open this to bleed the system several times timed when the cooling fan goes on. I cannot break my bleeder valve loose, so i cannot give results on this approach.

 

i had this problem recently with my 99 RL
the service center told me i had two problems:
1. thermostat was bad and needed replacement (this i expected, classic symptom)
2. cracked radiator (this i was NOT expecting) needed replacment
total repair bill apprx $1300

nope, i ain't too happy, especially after seeing new radiators are available for around $200

at least i have heat ...

mlloyd1