I posted awhile back after doing my new water pump. My gauge was doing the dance, so I replaced the temp sender and coolant sensor. This caused the gauge to peg out. I did the pegging fix at the same time, and still the same. Actually made it peg out with the key on and the car off...

2 weeks ago, I replaced my valve cover gasket. I took the connector off and found a break in the wires at the temp sender. I cut the wires off below the break and soldered new ones on and plugged them in. Still no luck.

Tonight I went back and pulled the cluster apart and soldered longer wires to the 2 green ones that needed to be swapped. I figured maybe they were pinched somewhere and getting interference. I was also given a new gauge cluster by one of the members here, so while I was in there I gutted my cluster and the one given to me for the temp gauge. Swapped them both over, still pegs out. Only it doesn't peg until the car is running. Starts out slow at first, then around 180-200 mark it flies over to the right peg.

I also noticed this morning that the oil pressure gauge wasn't reading properly. It would read 20-25 while driving, and at idle it would drop to 0 (at a stop sign, etc). I could also watch it drop when I applied the brakes or let off the gas. This is what prompted me to pull the cluster apart tonight and put longer wires on. The oil pressure gauge reads fine now, sits around 40 while idle and 60 when driving (the way it was when i bought the car

Does anyone have any ideas? All the air IS out of the cooling system, I have bled it 4 times in the past 3 weeks...

Does this sound like a bad temp sender or coolant sensor, even though they are brand new?

Any help is greatly appreciated. I really hope its not a bad sender, I don't exactly want to pull them out to replace them and have to bleed the system a 5th time...

Also forgot to mention that I tried pulling codes and received nothing but the annoying 1-2 flash pattern over and over....

The coolant sensor is completely unrelated.

Here is the schematic
http://www.2bluesc.com/pict...ematics/schalt16.GIF


I would tap a meter on the sending unit and drive it, then at the gauge pod and drive it. If you get consistant and proper readings at both, then it has to be a faulty gauge. If you get good readings at the sender but not the guage pod, then you have wiring issues.

[This message has been edited by 86GT3.4DOHC (edited 08-07-2008).]

Some item that may be worth checking.
Is the new sensor the correct part ?
The Temp. gauge / Hot coolant light uses the sensor shell as a ground path. Use of teflon tape on the threads may isolate the ground.

The gauge can be tested for operation with some resistors. The temp gauge will read 100 degrees with a resistance load of 1365 ohms and 260 degrees with a resistance load of 55 ohms. With some resistors close to those values, the resistor is substitute for the sensor, being placed between the sensor wire for the temp gauge and engine ground.( common values for resistors would be 1,300 ohms, and 51 or 56 ohms)
If the gauge does not read properly, then there might be a problem with the wiring.

You may have a bad ground somewhere beween the gauge and the engine block. More resistance = higher temp reading. A dedicated wire from gauge to the block is a possible brute force solution. You can check by running a temp wire from the ground post on the gauge to a ground point on the engine block. If it works, you can then run a wire out of sight.