HELP with heater - Toyota Nation Forum : Toyota Car and Truck Forums

snarf · 03-02-2009, 12:08 AM

on my 97 Camry the heater blows hot air when driving around and rpm's are above idle speed. But when sitting still and the rpm's at idle the air becomes luke warm but goes back to hot when rpm's go up. I have changed the thermostat and put all new coolant in and tried to make sure there was no air in system. What could be causing this? I've seen some people mention a weak water pump but the engine temp seems to be fine it doesn't fluctuate at all.

TexanF250 · 03-02-2009, 01:16 AM

I would recommend doing a search on this forum to see if someone else has had this problem and take a look at what they did to fix it. I too am new to this site and I've pnly had my Camry a very short while so I am not familiar with all of the issues yet and how each of the systems work.

You may find there is an actuator for a blend door that has failed or a valve in the cooling system to regualtes flow to the heater core that could be causing a problem.

snarf · 03-02-2009, 01:20 AM

I did a search but most problems relate to the heater blowing cold air or just luke warm air which usually is a thermostat issue. Mine blows hot air with engine rpms up above 1500 but as soon as they drop to idle which is 900 I get warm air. very confusing

TexanF250 · 03-02-2009, 01:40 AM

My Ford Superduty did the opposite of this and it was a problem with a low coolant level. Not much help to you though. If it were me, I would learn as much as I can about how this system operates and identify the various components that control it.

My daughter had a 97 Ford Ranger that would not heat up at all. That problem turned out to be a broken blend door in the heater plenum. This was/is a rather common problem with that vehicle.

I too did a quick search for your problem and probably found the same threads you did. Nothing exactly like yours. One guy swapped out to a higher temp. thermostat and was happy with the result.

First thing I would try to do is determine if it an air control issue or a coolant control issue then go from there.

Fund this thread on the subject. Youa re not the only with this problem. Sadly, this thread did not come up with a resolution.

1994 Camry no heat!!! Help

TexanF250 · 03-02-2009, 01:54 AM

Which engine do you have??

Do you have the same problem with the deforster?

Same problem at all switch positions?

You indicated that the engine temp reads normal? Where on the gauage is it reading? Does it read the same at idle (when not heating) and when moving (proper heating)?

TexanF250 · 03-02-2009, 02:06 AM

Below is a link to the service manual set for these cars. I don't think the Gen. 4 manuals ar there so you might have to grab the Gen.3 manuals and see if they look enough like yours. I suspect they are pretty close.

http://www.automotiveforums.com/vbul...d.php?t=497839

The AC portion is what you will need.