Temp Gauge
 

Hey guys, I drained all the fluid out of my radiator because it was real dirty and brownish and the gasket was bad on the thermostat so I decided to replace the thermostat and put new fluid in the radiator. When I am driving the truck runs approx. 180-190 degrees but from time to time (mainly when I am coming to a stop) the temp jumps up to 260 degrees. I push in the clutch and rev up the engine and it jumps back down to normal temperature. What could be causing this?

Re: Temp Gauge
 

Are you running a fan shroud?

Sounds like at rest your not getting the air to pull thru the radiator.

Re: Temp Gauge
 

It's all stock. Are you talking about the aftermarket fans that mount to the radiator?

Re: Temp Gauge
 

No I meant the factory one that fits behind the radiator and wraps around the fan

Re: Temp Gauge
 

Oh ok, yeah my truck has that.

Re: Temp Gauge
 

Fan clutch failed? Or maybe an air bubble?
Throwing out suggestions.

Re: Temp Gauge
 

Bad water pump? Maybe the impelled is trashed and only flows enough when at a higher RPM or moving. Also check your thermostat. It may be sticking?

Re: Temp Gauge
 

Someone suggested that I start by loosening up my radiator cap and driving for a short time. If that didn't fix it then have Autozone check my cap and or replace it. Then look into changing out my water pump.

Re: Temp Gauge
 

I would double check that the temp gauge is reading correctly first.

How many blades does your fan have? IIRC some have 5 and other have 7.

How quickly does the temp rise at idle?

Re: Temp Gauge
 

Several years ago I bought a radiator cap with a built in temp gauge in it. That way I can double check my temp and compare to my gauge. It has come in very handy.

Re: Temp Gauge
 

Not sure how many blades it has. I can check it this evening. It takes it some time before the temperature rises to 180 degrees. Maybe 5 or so minutes into driving, not sure about idle.

Sounds like a very good idea.

Re: Temp Gauge
 

you mention real dirty and brownish...
any chance it's fluid was mixed green and red?
could it have a stop leak in there?

Re: Temp Gauge
 

The water looked rusty. The truck sat for 10 months prior to me buying it without ever being started.

Re: Temp Gauge
 

oh ok good,couldn't do that here,it would crack,did it clear up?
anything but a nice bright green I'd reflush it

Re: Temp Gauge
 

Yeah I drained it and filled it back up with half and half