Heater not heating when engine is cold?

[Carl_Freeman]

Hi Guys,

I have a 2007 IS220d.

Its been a year since I last used my heater to heat rather than just cool or air con, and I cant remember how it 'should' function?

It doesnt seem to blow warm air until the car has been running for 20 mins or so and the engine temp is half way on the gauge,

until then its blowing cold despite being set to 23 degrees on the control, with or without air con switched on. Is this correct behavior?

cheers.

[madasahatter]

Turn it to full, then lower when your at a comfy temp.

[Linas.P]

I thought Lexus 2IS had not "heater" as such, like where is dedicated unit which burn fuel to actually heat (very rare in modern cars). I might be wrong but it just uses heat from engine and mixes it with fresh or cabin air to achieve the desired temperature... so yes until engine heats-up it will blow cold air.

[normski2]

Yep, it will take, typically up to 15-20 mins to get up to temperature.

It is a drawback of the diesel engine on the Lexus. My petrol will be warming in about 5 mins or so.

[Carl_Freeman]

ok, thanks, as long as its normal and not a broken heater or something :)

 

cheers.

[Hrky]

One more thing you could check, is the coolent level. It can happen that it is to low and there is no enought water level to heat.

[normski2]

That's a good point.

Given the number of HG issues with the diesel engine, you would be wise to regularly take a look/check of that coolant level.

Whilst there check the coolant for signs of oil droplets and pop the oil filer cap off and check for signs of oil/water sludge .... looks a bit like mayonnaise.

[thesmileyone]

All a heater is a basically a heat exchanger, it takes heat from the engine and exchanges it to heat up the cabin. The LS might have its own heater for the cabin (which heats oil) but the other models won't. So yes you can expect this. My 330ci used to heat up in about 3 minutes (big 3.0 engine in tiny engine bay!) my 2.0 tdi a3 takes about 20mins realistically.