Hi guys, i have an IS250 and the heater will not blow out warm air!. Ive tried setting it to manual, at different temperatures, and with/without a/c on but it keeps blowing out cold air.

The engine itself seems to warm up nicely, the temp needle sitting in the middle of the gauge after a couple of mins; but the blowers never seem to warm up - apart from when when the revs are above say 2000rpm, then it seems to be fine, but temp drops down again when revs go down.

Ive searched the forums and it seems that other people have this issue as well, and the advice seems to be something to do with the thermostat/coolant level/hoses, but nothing seems particularly clear to me.

I have a complete lack of mechanical knowledge, but im willing to get my hands dirty if need be, so i would really appreciate it if someone could give me some advice on what the problem could be and how to sort it without getting fleeced at the dealers!

 

Sounds like you have some air in your coolant lines...try and top off your coolant at the radiator cap (not the overflow bottle)...have the car running, pour coolant in, let it idle and you might see some air bubbles "burping" out, keep topping it off until the bubbles stop...hopefully that helps!

 

Thanks for your quick reply mate, i will give it a try soon as i can and post back with the results.

Has anyone had this problem and managed to fix it using this/alternative solution? - Im asking because it seemed that a number of people on the RX and SC seemed to have this issue, so maybe its another 'known issue' to add to any generic lexus sticky threads.

 

Actually I think it might be your thermostat.

I have had this problem before, not on my IS, but on a previous car.

Engine would warm-up but would not get any warm air in the car.

But try Quick123 suggestion first, it might be that as well.

Good luck

 

Try this:

Put the car on defrost on a hot day, see if dampness forms on the inside of your windshield. If so it might be a heater core problem, which is a separate radiator type deal that heats the cabin.

 

i had the same problem with an old car also. it was the thermostat.