DertyDOH

I've been losing small amounts of coolant here and there, and noticed my heat being only lukewarm when idle, while driving its blazing hot. I discovered a whitish film on the hose that goes from the heat control valve into the heater core. I replaced the valve and hose hoping that was the leak. Now a week later, I'm still losing coolant and there's now white film that looks like where water has been. So now I'm thinking it has to be either the heater core is leaking, or clogged?

johnnyg66

Are you getting anti-freeze smell inside car? Are your windows fogging up? If so than mostly for sure Yes.

That for me would be kiss of death because of the toughness of getting to it.

hotdawwg

Damn, my heat does the same exact thing. Luke warm at idle and then it blows hella warm when cruising or accelerating... I don't have a smell nor window fogging up though. I just thought it may have been something else

djbrown01

On my old car I had the same problem, even though it wasn't a Lexus.. I found it that I was a little low on coolant and since the heater core sat higher than the rest of the cooling system you would get an air bubble in there at idle, but once the car had some RPMS the heat was super hot... Try that if you wish, add some more coolant, and find out where the leak is or why you are losing it, or just treat it like any other maintenance issue and add coolant every couple days.. This is all dependent if you aren't having having the antifreeze smell and fogged up windows from steam like the other poster said..

LScowboyLS

agreed, with a leaking heater core, the windows will never get clear!

door331

Check your vacuum lines as well. Similar issue in one of our other vehicles where a line must have had a small leak so there wasn't enough vacuum at idle but everything was good while moving. Gluck.

hotdawwg

Cool I will look into this

DertyDOH

thanks for the input...not really getting foggy windows or anything. But I thought I felt a slight dampness where the kick panel meets the carpet in the passengers floorboard. It'd be so much to fix, but I only have 162k miles, tough decision on what to do if thats what it is

LScowboyLS

get in their with a blow dryer and dry the area where you thought you felt dampness, and see if it returns, and get someone else to feel it next time you think it is damp for a 2nd & 3rd opinion.

timmy0tool

iTrader: (7)

obviously isolating the leak is the first step. then when adding coolant you need to bleed the system properly. it took me a few times to do the sequence to get all the air bubbles out. lexls.com shows steps on how to do it.

also i suggest using toyota coolant, the red stuff. it's not necessary but it's best for the longevity of your water pump.

LScowboyLS

definitely use the red Toyota Long Life coolant, and make sure that little hole in the thermostat is positioned in the 12-o'clock position to help with the air bleeding!