OK, I'm pretty sure my thermostat is bad...

This crap has been going on with the Samurai for about a week now...at first it seemed incapable of cooling itself at times and started running way too hot. The first time was in city driving so I didn't think it was too abnormal for an engine with a small radiator and an engine-driven fan. Then it ran too hot on the highway for about 15-20 minutes. Normally if the engine's above normal operating temperature, it cools down in a matter of seconds when driving on the highway. Now this morning it starts running hot as hell, in city traffic but still way too hot. I've also noticed that the radiator is much cooler than the engine head after this happens.

Before I buy a new thermostatic valve, is there anything else that could cause this? I had a similar problem with my AE92 when the water pump went out (except the temperature suddenly and rapidly started climbing, I barely stumbled it to where I was going and had to take breaks on the way home), but the Samurai's water pump was replaced shortly before I bought it early last year.

A thermostat is what, $5? $10? Replace it anyway.

...and easy to change. Are you loosing coolant, or just running hot?

petegossett wrote: ...and easy to change. Are you loosing coolant, or just running hot?

It definitely doesn't have any leaks but the coolant seems to need topping up more often than you'd expect. I'll double check the weep hole on the water pump just in case it recently sprung one.

Could be a radiator cap. Is it doing it intermittently? Have you opened up the "burp" valve to see if there's any air in the system? Again, a cheap fix if it works. If you end up replacing the thermostat, buy a "fail-safe" one that'll default to "stuck open."

poopshovel wrote: Could be a radiator cap. Is it doing it intermittently? Have you opened up the "burp" valve to see if there's any air in the system? Again, a cheap fix if it works. If you end up replacing the thermostat, buy a "fail-safe" one that'll default to "stuck open."

I'll try that too...unfortunately I don't have many options for parts though, I'll have to go with an original stealership part (less than $9 still) . I'll look for a fail-safe one next time I'm overseas, that's a good thing to have in an offroad vehicle. (Hey maybe I should smuggle some back, I'd make a killing )

if you want to check your tstat before spending the money on a replacement, pull it and toss it in a pan of hot water. If it doesn't open before the water boils, it's bad.

GameboyRMH wrote:

poopshovel wrote: Could be a radiator cap. Is it doing it intermittently? Have you opened up the "burp" valve to see if there's any air in the system? Again, a cheap fix if it works. If you end up replacing the thermostat, buy a "fail-safe" one that'll default to "stuck open."

I'll try that too...unfortunately I don't have many options for parts though, I'll have to go with an original stealership part (less than $9 still) . I'll look for a fail-safe one next time I'm overseas, that's a good thing to have in an offroad vehicle. (Hey maybe I should smuggle some back, I'd make a killing )

How devilishy capitalist of you!!! Actually, that sounds like a fantastic idea. I'm guessing most folks there drive Suzukis (?) And yeah, sometimes I forget that you live on an island No running to vatozone for cheap parts, eh?

Does it have a clutch fan ?

If you would like, I can run to the parts house here, scarf up 10 or so, and ship via Amerijet to you with a "Creative" invoice. 25.00 for shipping, I send stuff to Barbados all the time.

I just realized I haven't updated this thread...I'm pretty sure it has headgasket issues now. It runs on three cylinders when starting and started idling low and rough on Friday. The amount of water coming out of the exhaust is suspicious and the coolant looks dark and smells odd.

Mechanic confirmed there's a leak between one of the cylinders and a coolant passage