REWSTER

i have a 2000 xj 4.0 i herd thies have an overheating problem, mine runs at about 210 and gets there pretty fast, i was wondering what the stock thermostat opens at because i was going to put a faster one in, also what degree faster one should i put in?
any help is appreciated thanks

96 XJ Sport

You will hear from others on here more technical than myself that the 4.0Ls are designed to run in the 210 range. If you are not going much above that during extreme heat or long idling periods, you are probably fine. How does it do in those circumstances?

If you go to the local auto parts store, they show OE thermostat as 195, but I have seen others here say that technically it was 192, but close enough. From my experience, I would not recommend going with a cooler thermostat. It was putting a band-aid on the real problem which for me was a bad fan clutch.

Bouncy

The engines run at 210 normally.

You can run a 185 tstat to help but it doesn't fix it if it is a problem.

If you get the engine running too cold, it wont switch its loop mode open/closed..thus you burn more fuel trying to "heat up" the motor.

BlueXJ

Bouncy has the rational correct. Leave the 195/192* thermostat and run the engine at 210* and you will be the happiest when you pull up to the gas station pumps.

REWSTER

thanks for the feedback its not really problem, i just never payed attention to any other of my cars so i was curious.

mike

i was thinking the same thing when i first got mine, but then i got on here and heard what these guys where saying. i know that mine runs about 210 to 215 all the time, except on the trails in the woods and it has got up to about 220-225 then the other fan kicks in and back down it goes.