LexoticJ

iTrader: (5)

As the title states my heater is blowing cold freezing air when stop but when I drive it blows out heat while on the in motion... have noticed this now for a couple months... any ideas where to start to check out what may be the possible problems? Links welcome to any previous threads that may show owners having this issue.. and I am way out of warranty on my 2007 is250 rwd....

oblivionis

iTrader: (2)

Your coolant is probably low. Check the level and top it off if needed.

https://www.clublexus.com/forums/is-...ol-system.html

LexoticJ

iTrader: (5)

Ok will do after I get it back from the shop as a raccoon killed my front bumper

slownlow07

iTrader: (1)

Definitely a coolant problem. I would recommend keeping an eye out for any kind of coolant leaks. I had my car (with no heat at a stop) for over a year. Figure I could do without since I didn't know the problem. Finally, early this winter my car started overheating. Got the water pump replaced and did the thermostat at the same time with new drive belt. Car has heat now after warming up, like a normal car would. I would recommend changing out water pump if the problem keeps occurring after you fill up the coolant.

gompka

iTrader: (6)

I would check your heater control valve, if its sticking or damaged it can cause similar symptoms.

Gville350

iTrader: (10)

I second the water pump replacement!

LexoticJ

iTrader: (5)

Thanks everyone. As soon as I get the car back I will check that out and go from there. Can anyone link the diy to the water pump in case I do go that route.

LexoticJ

iTrader: (5)

Also where is the heater control alive located on this car?

Eagletom5

I have same problem, blows hot air while driving and when I stop at a light it slowly gets cold. Did you find a solution?

Krystof

Hi mate got exactly same problem dont know what it is yet but defo not coolant level issue as mine is bang on without any leaks All symptomsare like in yours.

ohiois350

iTrader: (13)

this is just happened to my 07” IS350 a few months ago too

2013FSport

iTrader: (2)

Looking at the coolant reservoir level will not tell the story. The cap on the engine block needs to be removed when cool and even than trapped air *CAN MAKE* the coolant look full when in fact the engine is low on coolant.

The no heat at idle is a shoe in for low coolant that can damage the engine.

ohiois350

iTrader: (13)

Just an update: today i check my coolant reservoir and noticed is empty and the radiator cap seem like no coolant at top, and i just go head and fill up the coolant reservoir to the max and add some coolant to the radiator too, and wow it’s seem to take care the cold air flow out when my car stop. So far so good today guys

Droosive

Had this start happening to my 08 IS250 last year around October and got worse in February of this year. Just had Brakes Plus replace the Water Pump and Thermostat, as well as flush the coolant out. I’m pretty sure I killed the problem. The vehicle is in the shop as I speak so, I’ll give an update if any are interested.

lS35O

I resolved this issue a few years ago by simply bleeding the coolant. I followed a tutorial I found online, from what I remember I just removed the radiator cap while the engine was cold, then started it and let it warm up fully, then topped off the coolant and replaced the cap. Good luck with your car.