Need help with overheating m42... More problems: see post 8

[Codym42]

Hey guys, my car has been overheating lately. It all started on a long drive where I had to have the heat on for the needle to stay right below the 3/4 mark. I drove the car around town for a couple weeks after this trip and it seemed it would only rise above the 1/2 mark if I was sitting at a stop light. I took another trip (4 hours) and it stayed between 1/2 and 3/4.

Today, I changed out the thermostat. After bleeding it, the temperature stays right at the 3/4 mark. I have no idea what to do next. The entire cooling system was replaced in 2011 (new waterpump, radiator, thermostat, hoses, fan clutch, etc.).

Any help is appreciated.
Thanks

[Dj Buttchug]

engine is probably not overheating. id look into the gauge or the temp sensor being faulty

[Codym42]

engine is probably not overheating. id look into the gauge or the temp sensor being faulty

Hmm, you may be right. I just checked with an infrared thermometer and the temp was no where near 88 degrees celsius. It was only at around 60. I guess I'll buy a new sensor and give that a try.

[Balleristic31]

Ground nut on the back of the gauge 100%

[jntar]

Probably the ground nut like Balleristic said. Try slapping the dash a little when its above half way and see if it bounces up and down. If it does, that's a sure sign the nut needs tightened or the corrosion cleaned off it.

[Codym42]

I don't think its the gauge cluster. When I start the car from cold, the needle rises at a slow, steady rate from cold to 3/4. The needle does not wobble or bounce. The gauge cluster was refurbished last fall.

I'm still thinking about the brown temp sensor on the engine. It's the only thing that makes sense to me.

[Codym42]

The temp sender fixed it and it only cost me $8!

[Codym42]

Well, after driving it around it seems the problem has not been fixed. The gauge still reads at about the 3/4 mark. I got a pressure tester and UV light and was able to find a leak under the intake and fix it. After putting that back together and bleeding the system, the issue persists. I'm out of ideas. What do you guys think?

[Quadrajet]

Had the same problem with my car. Checked with a IR thermometer, engine at normal temps. Pulled instrument cluster to check on one I was selling. Noticed mine didn't have the nut on the backside. Found a nut and used a little dab of paint to lock it on. All good now.

[Codym42]

Had the same problem with my car. Checked with a IR thermometer, engine at normal temps. Pulled instrument cluster to check on one I was selling. Noticed mine didn't have the nut on the backside. Found a nut and used a little dab of paint to lock it on. All good now.

I think you're right. It almost has to be the gauge not reading correctly. What was your gauge reading before you fixed it? If it's the grounding nut wouldn't the gauge either read really low or be maxed out? That's what happened with my fuel gauge. It was stuck on full and had a loose nut.

Right now the temp gauge rises slow and steady and stops at around 3/4 and fluctuates depending on whether or not I have the heat on. It's almost like the gauge is working but just reading wrong. I'm seriously considering adding an aftermarket water temp gauge.

[roguetoaster]

I think you're right. It almost has to be the gauge not reading correctly. What was your gauge reading before you fixed it? If it's the grounding nut wouldn't the gauge either read really low or be maxed out? That's what happened with my fuel gauge. It was stuck on full and had a loose nut.

Right now the temp gauge rises slow and steady and stops at around 3/4 and fluctuates depending on whether or not I have the heat on. It's almost like the gauge is working but just reading wrong. I'm seriously considering adding an aftermarket water temp gauge.

Check your engine ground. If the coolant gauge reads accurately after heating the car then switching off followed by turning the key to accessory then it may well be the main ground.

[Codym42]

Check your engine ground. If the coolant gauge reads accurately after heating the car then switching off followed by turning the key to accessory then it may well be the main ground.

Hmm, I'll have to check that. Thanks