TRM04

Hello,

I've only had my LS fora bout 2 months and never really paid much attention to the thermostat reading on the dash until today. I noticed that the needle sits a little above the half way mark (3rd tick marking from the bottom). Is this normal? I'm only concerned because none of my pass cars have ever passed the half way mark at normal driving temperture. Is it normal? Where do your needles sit?

The car has about 83k on it and I'm not sure if the radiator has been or needs to be flushed. Some cars need a flush sooner than others...is this one of those cars?

Thanks for help!

SharpLS-96

If your reservoir is full when the car is cold then it’s running a bit to hot, the temperature gauge should be sitting right in the middle once the car is warmed up. Lexus’s are not known to run hot at all so it sounds like you have a bad thermostat. If your going to change the thermostat I would flush the entire system and replace the hoses at the same time.

Here is what I would do......flush the radiator, change both the upper and lower radiator hoses, new heater hose, and a new thermostat since you don’t know if any of its been done prior to you owning it. If the old coolant is really dirty when you drain it you might want to use a chemical flush like “Prestone Radiator Flush” or something to clean out the system. Most auto part stores carry it. Also make sure to use new Toyota Extended Life Coolant (Red Color) when refilling. The car should run fine after that. If you do it yourself parts will cost roughly $100 or so. If Lexus does it then your looking at a price tag of $300 or so to change everything I mentioned.

IMO It's better to be safe then sorry cause no one wants to get stuck on the side of a highway from overheating in August of all months!

Good luck!

wwest

If your engine water temperature gage consistently rises to the same position and basically remains there while the car is in operation it is likely you simply have a "miscalibrated" gage. Not at all an uncommon occurrance, but certainly less common on a Lexus.

I assume two months of satisfactory operation otherwise. If it bothers you have a mechanic check that the engine water jacket temperatures are within the correct operating range.

"If your reservoir is full when the car is cold" SOMEONE HAS GONE AND RESCINDED THE LAWS OF THERMODYNAMICS.

As a general rule your (overflow) reservoir should be "fuller", by about 2 qts, when the engine is up to temperature than when it is cold. When you start a cold engine the cooling water expands as it heats and the "excess" is forced by pressure into the reservoir. As it cools and contracts suction pulls the excess back into the system.

The only time you're likely to see a full reservoir when the engine is cold is right after someone has just (over-)filled it. Cold is when about two qts have just been sucked back into the system.

SilverLS400

thats the same point my needle rests on. I got the car since dec. and it sits there when fully warmed up. put on 7,000 miles and no problems. Its good so leave it the way it is.

retrodrive

I had some constant overheating problems till I replaced my water pump. That is one of the common problems and it needs to be replaced after 100k miles or so.

Baker Bootleg

My needle sits jsut below the middle. I dunno why? even when i drive it for a long time it never goes past that.

retrodrive

it supposed to be like that...pretty normal

wwest

retrodrive:

I have NEVER seen an automotive water "pump" fail.

I have seen water pump bearing failures and bearing seal failures, but these NEVER directly resulted in over-heating problems.

When the water pump bearing seal fails you start losing water soon after. And if you don't happen to notice that then you will certainly notice, HEAR, the resulting bearing failure soon thereafter.

hyperopt

Water pump's efficiency do decrease with age in poorly maintained cooling system (no offense to anyone) due to rusty or chipped impeller. Otherwise, it should either work or fail (as described by wwest) and not something in between.

healerhand

When i got my LS, it had water pump problem. Anyway, while i was changing the water pump (it had 125k miles) i also changed the radiator, thermostat and few other things.

My LS temp is about 1/3 of the tempt. gauge, its below half.

dc