Heavily overheated - over 260 degree water temps

[4to10cyl]

I was cruising around town on Saturday, only about 60 degrees out. I stopped at a stop light, sat there for a minute and then I pulled into a gas station to talk to a friend I saw. Next thing I know the dash is dinging.

My oil temps were up to 245 and my engine temps were peaked over 260. I shut down the truck and popped the hood. The coolant was boiling over into the overflow bottle. I waited around 10 minutes and started it back up. Temps hadn't moved, I turned on the heat and it cooled down in less than a minute.

Now this is the first time I've seen it anywhere near this bad, but it has creeped up a little bit before. I'm pretty sure it's the thermostat but just want a second opinion from you guys. If so I'm going to get one of the 172 degree ones ordered up.

 

[labontecsi]

Try "burping" the system.

Check coolant level, then with the engine running, loosen the bleeder nipple on the t-stat housing(10mm deep socket) let the engine idle -coolant will come out of the nipple. Close the bleeder when there is no air, just coolant coming out-you may need to rev the motor a little.
when the engine comes up to temp and the t-stat opens repeat the process.
Keep an eye on your coolant level while you do this.

 

[Westxsrt10]

I'd replace the thermostat for sure as its not a difficult job.
I replaced mine with a 172 degree but saw no cooler temps, truck does take longer to warm-up now.

 

[Yellow venom]

excellent advise here,I would guess the T-stat didn't open so the antifreeze in the block was just recirculating not running through the rad to cool it down and that would cause the engine oil temps to rise too,try the bleed,but I would be changing the T-stat for sure,like Westxsrt10 said its not a hard job at all,a possable other cause could be low antifreeze in the system also,just my opinions,good luck on the fix.

 

[FlyingLow]

Any problems with your power steering? The cooling fan uses the same hydraulic fluid. When my pump went out my temps went up. Make sure your Hyd fluid is not low also.

 

[Ram From Hell]

I'd replace the thermostat for sure as its not a difficult job.
I replaced mine with a 172 degree but saw no cooler temps

That would probably be because you have not had your truck's computer reprogrammed to activate the fan at a cooler temperature.


.

 

[Dave T(BADVENM)]

I had a similar issue while road racing and found that the power steering pump had failed. I thought it was worse but after waiting an hour or so I started the truck back up and oil/water temps returned to normal levels.