Temperature Gauge

[Blue90]

Thank you both for your comments.

I will get into the car this weekend and report back.

[Blue90]

This morning I replaced the Coolant Temperature Sensor. The hardest part was getting my fingers in there to disconnect the electrical connection. After that it was easy using a deep socket and an extension bar on the ratchet. I used MXLOC low strength thread locker on the threads (similar to Purple Permatex, it's even colored purple); it appears to be holding well.

I started the car and after a minute put it in ECM diagnostics; ED 04.

Air temp about 85F.

The temperature started out in the 20'sC/70's-80'sF,steadily rose to 82C/180F (thermostat opened), stayed there for a minute, then went down to 81C/178F; rose back to 82C, lingered there, then slowly went up to 86C/187F, fans went on LOW mode. Temp went down to 82C, fans went off. Temp then slowly rose (LOW fans went on at 86C) and stayed there (I'm using Ryan's reprogrammed PROM).

I went for a drive in the neighborhood. Temp stayed at about 86C (fans on LOW); when I put the AC on, temp went up to 91C/196F (fans on HIGH).

I got on the highway for about 20 minutes. Temps did not change much; 86C w/o AC; 91C with AC.

Although this is MUCH better than it was before (high temp at 91C/196F compared to 110C/230F), and I feel much better driving the car now, it seems as if it's still running hot (considering the reprogrammed PROM and the 180F thermostat).

Should I power flush the cooling system, change the thermostat, or just leave well enough alone?

[padgett]

Sounds like a clogged radiator, either the tubes on the inside or the fins on the outside. I'd remove it, take to a radiator shop, and have it tested.

[Blue90]

:)SUCCESS!

Brought my car to the shop today to get the radiator checked out; and I drove out with a new one.

They saved the old radiator to show me: bottom center of the radiator was bent up about two inches, bottom rows all squashed; there was also much build-up of debris on the radiator opposite the pusher fan, blocking most of the fins.

Had them install a new Stant 180F thermostat while it was there.

Before leaving their lot I started car and let it idle. Outside temperature was 75F and car was warm from their testing. In ECM diagnostics, ED04, temperature started out in the low70'sC, fairly quickly went up to 82C/180F, thermostat opened, temperature went down to 77C/171F.

I then drove around the neighborhood for about 20 minutes, sometimes parked and let car idle.

Temperature never got above 81C/178F.

It was 5 pm when I got the car from the shop. I didn't feel like dealing with rush-hour traffic on the highway so that test will come tomorrow. However I'm sure car will perform fine.

I would like to thank everyone who gave me advice during this process. It was definitely a collaborative effort; it would have taken me a long time to figure this out by myself. That's why this Forum is so great.