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Intermittant temp gauge

On a 2008 Jeep patriot, when first started, the engine temp gauge is dead and remains so until the car is driven at least 30 minutes (15 isn’t long enough). BUT it must be shut off, then restarted, and MAYBE it’ll kick back into life. It never comes back to life in the middle of a drive.

The test for the instrument cluster when given while its working, shows it to be fully functional, but when its dead it remains so during the test.

The dealer has already replaced both thermostats.

Any thoughts?

Both thermostats? I never knew there was more than one thermostat in the engine, and the thermostat would not be directly linked to the instrument cluster.

Did they, perhaps, replace the temperature sensors or senders?

If the gauge remains non-functional during the instrument cluster test, I’d say the gauge is bad.

Keep going back until they figure out what’s wrong. That’s what warranties are for.

Assuming he’s changed the temp sensor that provides the siganl to the gage, it’s time the dealer replaced the gage. The D’Arsenval movement is hanging up.

My guess would be the sensor. I agree with you on its replacement. My thought was if it was the thermostats, engine operation would have suffered and I would have noticed.

Regarding the Gauge test (hold down odometer button while turning on ignition…which lets all gaudes and lights operate), when the car is warmed up and the gauge is functioning, the test has the gauge functioning as well (It goes all the way, then stops at 12 o’clock, then returns to zero) That’s the thing that says it ISN’T the gauge, but something being kicked into life by engine warmth and re-ignition.
Thanks for your thoughts. The chasing of warranty satisfaction is exhausting.

What’s the D’Arsenval movement? Sounds French

It is a particular design of the meter movement found in more expensive meter designs. If the meter has already been replaced I would suspect a intermittent problem with the power source to the meter. By checking for voltage to meter while the trouble is happening would confirm that is the trouble or not.

By leaving it with the dealer overnight, the probability is that it will be malfunctioning first thing in the morning when they look at it. Still doesn’t explain why two parts were replaced that probably weren’t necessary in the first place.

They were most likely just guessing at the trouble. Intermittent problems can be hard to get rid of if the trouble wasn’t happening at the time they worked on it. They just have to try something and see what happens.

left overnite…didn’t work in morning as predicted…was the instrument cluster…fixed under warranty.