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General Information => Troubleshooting => Topic started by: mtnbob on February 27, 2009, 10:48:56 am

Title: Temp Gauge showing overheat but engine not hot
Post by: mtnbob on February 27, 2009, 10:48:56 am

If temp gauge is maxing out now and then at start up and while driving, but car is not even hot, where would you start looking for the short?  This used to happen when it was raining hard, but now it is doing it more.  :shock:

Title: Temp Gauge showing overheat but engine not hot
Post by: vanbcguy on February 27, 2009, 05:39:05 pm

I'd personally start by disconnecting the sensor and watching to see if the gauge still goes nuts.  That at least rules it out so you can check further...

I guess the usual places where problems show up - bulkhead connector for the wiring harness is usually a good one... But definitely rule out the sensor first.  Mostly because it's the easiest thing to fix!

Title: Temp Gauge showing overheat but engine not hot
Post by: Rich_91 on February 27, 2009, 06:38:01 pm

definitly check the sensor first. When I first got my jetta, the temp gauge would go right up to the top as soon as i turned the key to on. The flashing light would be there too.

Unplug the sensor. if the light goes out, and gauge goes to the bottom, then a new sensor you need. (in my case anyways)  :)

Make sure you get the right sensor tho, my local stealer had a hard time getting me the right one. (Maybe the parts guy was just a putz tho?)  :lol:

Title: Temp Gauge showing overheat but engine not hot
Post by: mtnbob on February 27, 2009, 06:50:58 pm

I think it must be my connection to the sensor. I wiggled the connection and it seems to be working fine. Does this mean the sensor is going bad or just a bad connection?

Title: Temp Gauge showing overheat but engine not hot
Post by: jtanguay on February 27, 2009, 09:54:23 pm

Quote from: "mtnbob"

I think it must be my connection to the sensor. I wiggled the connection and it seems to be working fine. Does this mean the sensor is going bad or just a bad connection?

you might just need to clean the contacts.  i find WD-40 works pretty good.  brake parts cleaner should work also.  some die-electric grease will help prevent this in the future  :wink: