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Thermostat Stuck OPEN?

The most recent starting cycles have shown a very slow warm up of my motor. Last night, and this morning, the needle did not even approach midscale until after I had been on the freeway for several miles. I live two miles from the freeway onramp, and my temp is normally to midscale before I get there. Today, the scale was only about half way between stone cold and midscale, and perhaps below (colder) than that. I got onto the freeway, and the needle remained pretty much stuck in place for more than 5 miles, then it suddenly began to move to midscale. Once it started going, it went to its normal reading.

My inclination is that the tstat is stuck open. Any other thoughts?

Reply to
Jeff Strickland
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Reply to
L.W.(ßill) Hughes III

your radiator may be low on water. old john

Reply to
johnny

I have a'97 TJ and my thermestat failed "open" Better than failing "closed".

Reply to
Jimmy

If the radiator was low on coolant, it might overheat, but low coolant would not be a cause of slow warmup. Sounds like your thermostat is stuck open or stuck partially open.

I just replaced my thermostat with a Stant Superstat thermostat, but any brand name good quality thermostat with the right temp range will do.

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While you are replacing the thermostat, you might as well flush the system and add fresh coolant at the same time.

Tom

Reply to
mabar

Reply to
RoyJ

yep.

Reply to
jbjeep

When modern thermostats fail, they are designed to fail in the open position. I'm betting that's what is happening on yours Jeff.

Jerry

Jeff Strickland wrote:

Reply to
Jerry Bransford

Yep stuck open and it does not take mouch, I replace both the thermostat and radiator cap when I flush the coolant every two years (including the so called long life stuff) and have never had a problem in all my years of driving. Many people neglect the small things usually beacuse the small things are a paon in the butt to get at or check.

HarryS

Reply to
HarryS

My `79 CJ-5 once failed closed, I could drive all of a half mile at a whack. My `89 Cherokee once failed open.

Reply to
Lee Ayrton

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