why is my gmc suburban temp gauge fluctuating

90

Asked by Jan 26, 2013 at 07:42 AM about the 1996 GMC Suburban K1500 4WD

Question type: Maintenance & Repair

a few days ago my temp gauge started to fluctuate and at times goes in the red zone and the check gauges light comes on and i get no heat, then it goes back down and i get heat. at times it stays steady and then starts to fluctuate. i changed the thermostat, belt and the coolant level is ok. the water pump is 3 years old and the rediator is 4 years old the head gaskets check out ok. does anyone have any suggestions?

10 Answers

How fast does it fluctuate? I mean does it slowly go in to red then back down, or suddenly jump up there, then flip back to middle? You seem to have done all the right things, a 4 year old radiator should be in just fine working order...it could possibly be the sending unit, check the connection to make sure it is secure. Or just replace it, it is not expensive

4 out of 4 people think this is helpful.

This is not the exact one, this is for an 'idiot light' not a gauge but will look similar

3 out of 3 people think this is helpful.
Best Answer
90

it fluctuates slowly and at times stays in the normal position had a feeling that it my be a sensor or something, will let you know how i make out and thanks

1 out of 1 people think this is helpful.

Please do. Let me know that is. And if you click on the image ....the drawing.. it gets bigger so you can see it.....David

1 out of 1 people think this is helpful.
90

put the new sensor in and still having the same problem, i also replaced the radiator cap for the heck of it. this is starting to drive me nuts! any suggestions? thanks

7 out of 7 people think this is helpful.
60

I have same problem with my 99 suburban. U ever figure out?

6 out of 6 people think this is helpful.
90

i think i have. noticed this past summer that everything was normal but when i started turning the heat on this fall the gauge would start to fluctuate if i turn the heat off the gauge goes back down to normal so i believe it's the dash switch. hope this help's you out.

1 out of 1 people think this is helpful.
10

no one ever found out why this is so? my 94 k1500 Blazer does the same exact thing...

1 out of 1 people think this is helpful.

Had something similar changed the temperature sensor and noticed that the prongs on the sensor were slightly cocorroded. ..I plugged it back on without cleaning the female plug and it was still hesitating and temp gauge was spiking. . I took some electro clean and a small rat tail file cleaned it up good.. Problem solved. . Hope this helps. ..

I have the same prob on my 97 Yukon. I had a 93 Camaro with similar prob. Must be a 90s chevy defect. Neither car acted different, just the temp gauge and check gauges light.

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