SteveWs6

iTrader: (1)

I replaced my temp sensor and temp sensor pigtail due to the fact that my car would sometimes not get a reading on the temperature and when it didn't, it would run like crap. Once I replaced them it's been fine for a few days but the issue came back.

What happens is i'll drive it, for example, to a gas station, it'll be perfectly fine. Start it up, and start pulling out of the place and then the temp gauge goes below 0, it buckles, temp gauge goes back to normal, and I baby it to get up to speed at the temp goes back below 0 and isn't getting a reading again. It has done this several times.

Could it be the Thermostat possibly getting stuck open or closed and maybe causing the temp sensor to read air for a second and throw it off?

I have full coolant, and i've checked a lot of other things (fuses, pinched wires, connections) as well as done many searches before posting this thread. Please let me know if you have any ideas.

lt1pwr1

iTrader: (1)

I would start looking beyond the sensor and pigtail then. You probably have a wiring issue between the pigtail and the ECM. You could also have a bad ground somewhere but I"m not sure which ground goes to the temp sensor.

There are some in the front of the engine bay that you can check to start with...also some on the driver's side head in the back.

wssix99

iTrader: (5)

If the thermostat was bad, you should still get some kind of reading.

Have you measured at the overflow bottle and looked inside the radiator?


Here's and article that might help: www.wellsve.com/sft503/counterp_v2_i2_1998.pdf‎

SteveWs6

iTrader: (1)

I figued about the Thermostat but I just changed it anyways today, it was the original one on there with about 85000 miles so I guess it couldn't hurt. And I did measure at the overflow bottle and looked inside the radiator.

I will check the grounds as the other poster said. I have visually inspected my engine bay but I did not look behind the driver side head. Please let me know if there are any other grounds and stuff I should look for. If the issue continues I will look further into the wiring between pigtail and ECM

SteveWs6

iTrader: (1)

I changed the thermostat just to see what happens and on this very hot summer day, the problem came back. First startup, perfectly fine. 2nd or 3rd start up, temp guage turns on and off and the car starts cutting out. Later in the day I started my car and visually inspected the engine compartment for pinched wires, loose grounds, etc... I moved wires around and jiggled them a little to see if the temp sensor would stop reading... moved around the whole engine bay and nothing happened. I am confused ...

wssix99

iTrader: (5)

Does your temp gauge still go to 0 when things go off the rails?

SteveWs6

iTrader: (1)

It does go to to zero when I am having issues, then it'll pop back up to 190 or so for a second, go back down and most of the time either stay down or stay at 190. When it is at the 190 it pretty much runs fine.

I soldered the connection where I put the new pigtail in and seeing that this sensor is based on resistance I am hoping that this could be what was causing my problem to continue, though i'm not entirely convinced.

And how am I supposed to check these grounds on the back of the heads?? Impossible to see back there. Under the car?

wssix99

iTrader: (5)

If it were a ground problem, I'd think you'd see multiple issues. You problem seems to be linked with the one going in/out. It does sound like a loose wire somewhere.

SteveWs6

iTrader: (1)

Any pointers on where to check? I didn't really think it were a ground but it's all I can think of right now. I will continue to inspect the wiring and stuff the best I can. Any suggestions and tips on where to look will be appreciated!

wssix99

iTrader: (5)

I'd start by taking off the loom an tracing the wires back to the PCM so look for any melts/cuts.

You might even have a problem at the PCM, which can cause odd problems like this. If you do, you should have a new PCM seal kit handy to put that back together: https://ls1tech.com/forums/general-m...onnectors.html