gmoney94

The car has been having trouble keeping constant heat, especially when sitting still, but not exclusively. The car will warm up in the morning, the cabin will get to temperature (in motion), but then it will suddenly get cool/cold again (DC area). The cars temp meter stays pegged below the halfway mark, even when parked, so my assumption is that I have enough coolant. I'm going to check that today just to make sure, but I dread driving when the temp is below 50 degrees now.

What other pieces could be stuck/bad?

Johnhav430

Just theoretical because I haven't had an issue myself.....I know that if there was air in my Maxima's system, I had no heat even with the coolant being topped off (I changed it). What I did was to gently open the radiator cap with a towel, and I heard air rush out. Put it back, and instantly there was heat. With the LS430, my temp needle was perfect when I picked up my car. But the next day I saw no coolant at all in the reservoir nor radiator. I cannot say if the heat worked or not because I don't remember using it. Just that temp with coolant missing, was same as today and always.

On other cars, there can be a valve that opens and closes electronically going to the heater core, but I don't know if our cars have that, and where it's located. In a Mercedes S it was on the firewall in the engine compartment (I watched Tavarish change it on YouTube on his S600 recently)....good luck.

p.s. one other observation, there have been times I wanted outside air, even if outside is only 40F. I would turn my temp down to 65, not MAX COLD, and warm air would come in, not what I wanted. Something is making that decision in the car, that 65 > 40, so heat is needed....

gmoney94

Thanks Johnhav430.

Funny you should mention the air pocket. When I had my TB/WP changed several months ago, I got about two miles down the road and my temp gauge began to rise precipitously. I turned right around and had the tech take a look. He said that an air pocket was caught in the system, and that was likely causing the coolant not to do it's job. They fixed it, added more coolant, gauge registered normal and I was on my way. Now I wonder if I still have a little air in there - would a full radiator flush service do the trick, in your opinion?

Johnhav430

If you had the TB done just a few months ago, then your coolant should be fine, meaning doesn't need to be replaced......I do know that when I had my TB/WP done, I had to refill my reservoir for it to be topped off, and I may have done it yet a 2nd time....

This thread has someone who had the problem, and topped it off for the 3rd time and restored his heat!

https://www.clublexus.com/forums/ls-...wing-cold.html

gmoney94

Hmmm, maybe I just don't have enough coolant. I'll swing by a gas station on my way home and buy another jug before I make an appointment with a tech. Thanks!

Johnhav430

Walmart should have this....my indie likes the red stuff (gets changed more frequently and was I think in 2003 and older) better than the pink stuff....pink is super long life, but should be safe regardless.....so if you mix red into pink, then your life is shortened to that of red. I believe if you add pink to red, then your life is still that of red. Let us know how it goes!

https://www.walmart.com/ip/Valvoline-Asian-Vehicle-Antifreeze-Ready-To-Use-1-Gallon/49660461?action=product_interest&action_type=title&beacon_version=1.0.2&bucket_id=irsbucketdefault&client_guid=29ee7bd1-f14b-4c67-328f-00902ae1c93e&config_id=106&customer_id_enc&findingMethod=p13n&guid=29ee7bd1-f14b-4c67-328f-00902ae1c93e&item_id=49660461&parent_anchor_item_id=144057949&parent_item_id=144057949&placement_id=irs-106-t1&reporter=recommendations&source=new_site&strategy=PWVAV&visitor_id=UwDs7dZjzuZVgfH_rkC69w

edit: This states pink was introduced in 2002 models of Lexus

I have seen where a tech with a 2006 actually prefers red, and uses it in his own car....and I've heard green is actually safe with all, just not orange which is GM Dexcool, that should be kept apart and used only with orange...

https://www.clublexus.com/forums/ls-...ml#post5195696

gmoney94

Great info, thanks!

gmoney94

UPDATE:

I topped off my coolant before I left work yesterday, and then I went to the shop. My plan was to have a flush and fill to force out any air in the system and it hadn't been done since I've owned the car. I casually explained my heat problem to the tech - who I trust - and he said "that's not the greatest way to see if your system is working or maybe leaking". Long story short he recommended a pressure test for the system to see what was or wasn't going on.

Well, the results were not great. Coolant was leaking from a couple of gaskets - I was able to take some pics and a video for my edification. Turns out when I got my TB/WP done, the shop (different one) used a product called RTV I think, essentially a liquid gasket that hardens relatively quickly instead of a traditional OEM gasket), The current shop thought it may have been done poorly and it never set well enough to create a thorough enough seal. All toll, parts (gaskets and a new thermostat)/labor and the pressure test is going to set me back around $700. They have to order everything so it won't get it done until Monday morning. I bought more coolant so I can top it off before I drive. Luckily the car's temp gauge has always read cool, so I think I've always had enough coolant to protect the engine.

2KHarrier

What has the shop that actually did the work said about this? I assume you've contacted them and shared the findings??

gmoney94

There is no smoking gun yet, and until the new shop has everything taken apart, nothing will be known definitively. The tech is going to take pics of each step of the process, so if I need to seek redress with the other shop, I'll have his pics and notes on the repair.

2KHarrier

Good job.. Cover your ...bases..

gmoney94

UPDATE:

The shop will be able to get the parts by this afternoon, so it will get done today provided I can get out of work a bit earlier. Fingers crossed!