Possible Thermostat Problem

[tucker0104]

I am thinking my truck has a stuck open thermostat. The needle barely comes off the Cold indication no matter how long it has been running. How can I tell if it is stuck open? Running it probably isn't an option since my oil cooler is leaking. I am about to change out the seals and gaskets and thought I would go ahead and change the thermostat since it is only like $20. Does that sounds like a good plan or would you just leave the thermostat? Does anyone have a certain brand thermostat that they recommend?

[dazed01]

I would just go ahead and put a thermostat in and change your hoses if they need changing at the same time. It's cheap and easy.

[BrianH]

If its stuck open you'll see that it's open when you pull the thermostat out to inspect it.

[jesilvas]

Just replace it.
If you come out of the job, run it, and you're still not getting temp change, I'd suspect the ECT sensor then.

[gaspipe]

The OE thermostats have a suck factor to them after many miles. I've had three 7.3's and each of them had the OE thermostat fail at 200-275k miles. Replace it and and keep going forward. You want that diesel hot, not at the C mark.

[tucker0104]

Any brand of thermostat that you recommend in particular? Thanks for the help.

[dazed01]

Originally Posted by gaspipe

The OE thermostats have a suck factor to them after many miles. I've had three 7.3's and each of them had the OE thermostat fail at 200-275k miles. Replace it and and keep going forward. You want that diesel hot, not at the C mark.

200k miles is a long time. If the thermostats last that long they are designed pretty well. I've replace a Lot of thermostats on newer cars at 30-60k miles. Some stick shut causing the engine to overheat and warp the heads. Newer cars monitor the ect and will determine the thermostat is faulty before it even seems to be acting up.

[tucker0104]

What brand thermostat do you recommend?

[dazed01]

I think I put a stant in mine.

[CT Performance, Inc.]

X2....a Stant or a stock Ford...no need for the aftermarket hotter ones at all.