Hi guys, I have a Not Monte Carlo car question.
In my Mrs. LEXUS, the heat in the cars is kind of funny. It's only hot when Driving above 55 MPH. I checked the coolant levels in both the reservoir and in the radiator. I could see flow in the radiator and the reservoir was only Half full but it the fluid in it was hot too. I had not checked it since early spring.
It is a 1993 ES 300 with a 3.1engine in it.
You can feel some heard but it is much colder than my Montes. Much cooler!
If there .is plenty of fluid, the blower works and the fluid great hot. Why is there minimal heat in the car?

 

The engine might just be too efficient. When you think about it, heat in a car is completely a by-product of engine inefficiency. I've only owned 2 Japanese cars and neither of them produced much heat and took a long time to come up to temperature. But they were 4-bangers. The big ol' cars of the 70's produced awesome heat! I never owned anything older, but they probably were even better before that. My '95 Bronco is inefficient as hell - and hot as hell too.

I would thing the Toyota V6 should make decent heat, but not like a 3800

 

It may be air in the system. At work USPS we have 2008 chevy uplanders
an they are known to get air trapped in the system.. They make a tool Coolant Vacuum Kit.. to get all the trapped air out..

 

-Incorrect temp t-stat (or a failing t-stat)
-Plugged/clogged heater core
-Air in the system

Personally, without knowing the car, i vote for a failing t-stat or plugged heater core. If it is the core, a coolant flush MIGHT be all she needs.

 

Despite the coolant feeling hot in the reservoir JC...
It could also be possible that theres far to much Antifreeze VS water....
I would definitely check to see what ratio it has as far as the Mix...It may be rated to high for your area.. (weather wise) Your coolant doesn't need to be setup for -100 below zero.

But I think there has been some great suggestions... Air in the system, complete fluid ,radiator flush, Bad Heatercore.... Since its a 21 yrs old Vehicle. Heatercores do tend to wear out. (Meaning there no longer able to hold/transfer the heat) per the original design.

If I'm not mistaken... I believe the Lexis and other models like fords have a under the hood heater control valve.... Despite the coolant being "HOT" maybe that valve is no longer opening wide open? Thus not allowing the correct amount of fluid to travel in/thru the heatercore?

I've never been a big fan of the Lexis ... But maybe its just time for some regular routine maintenance?

 

My truck was having issues providing warm in cabin air, ended up being the T-stat. Same thing last week with my friends F150. If it's not too hard to access, you can always do the remove and boil it in a pan of water test. Have your new one handy, if the old one fails the test you can drop your new one right in, or return the new one if it's not bad.

 

Thanks guys, I will have to check all this out. Her 21 yr old car mechanicly, is in better condition than my YellaJAC. I would drive her car to Florida and back and not worry about it braking down. But that doesn't mean it's perfect I know. I have done tune ups and oil changes on it and the coolant has been drained and refilled with 50/50, but I haven't done a flush. Got a few things I need to do to it. But this is the first Special Problem it's had.