Is200 Cooling System Help Needed

[blahmartinblah]

I have a 99 IS200 sport, 98000 miles.

The engine is very slow to warm up, previously it would be at normal temperature within a few miles, now it is barely registering on the gauge after that distance.

During motorway driving, the temperature gauge only reaches approximately ~1/3 on a 30 mile trip. Previously, the gauge sits at 1/2 deflection during normal driving.

The heater only blows warm air, I was able to have it on maximum heat setting during that 30 mile trip without it becoming uncomfortably hot.

When stationary, the temperature gauge reaches 1/2 and the radiator fan can be heard to switch on/off. It seems stable like that, what I would expect.

The radiator reservoir was checked and was below the lower limit. I refilled it and the problem still occurs.

No visible leaks.

Minor gurgling sounds on startup, indicating possible trapped air. I’ve squeezed the radiator pipes to try expel it, next I’m going to try running the car on a hill to see if it will cure that.

Any suggestions? I’m suspecting the thermostat could be stuck in the open position, meaning cold water from the radiator is continually flowing into the engine so it doesn’t reach its normal operating temperature unless the car is stationary with no airflow to the radiator. Does it sound possible? Or any other likely causes?

Martin.

[Shorty1979]

i would second your suspection. that is the first thing i would check

[shak]

Alright mate, I would definitely say its the thermostat mate, it sounds like its staying open

shak

[shak]

a

[blahmartinblah]

Thanks. Can anyone help with where the thermostat is, and any tips for removal/refitting/where to purchase a replacement for a decent price?

[Rikos]

I would have said a dealer should would be a good first try and see how much they want for it. Then there's always eBay and 25/7 spares.

I can help with fitting or removal though i'm afraid.

[Rob]

Thanks. Can anyone help with where the thermostat is, and any tips for removal/refitting/where to purchase a replacement for a decent price?

http://www.bahamutcars.com/workshop/

[Scorps01]

Nice find Rob, i'll keep that :D

[blahmartinblah]

Awesome link, thanks mate!

Does anyone know the Toyota part number for the thermostat? (and gasket if its seperate..). I can't see it on that site..

I'll try pick one up from my local Toyota dealer rather than Lexus because its much closer, but they always seem to need the part number because they can't look up Lexus cars.

Martin

[Rob]

would just give the lex dealer a call mate - have not found a parts catalogue yet.