Temp Guage-Help

[jakeass0]

I recently had my blower motor making some awful noise, got a lot louder than normal. I tore into it and found a couple of in cab filters. Dirty as could be. Replaced them but noise still present. I then took out the motor itself and found a little "helicopter" inside making the racket.

I now find that my temp guage is working when I start my truck but about 5 secs after it drops. All other guages are working properly and yes it was working before I started into this project. I don't know why but I always look at my guages. Any help would be grateful. Thank you.

 

[ygmn]

What temp gage?

The engine temp gage?

I presume you have a 2002 since you have ac filters...

 

[jakeass0]

Sorry. Yes it's a 2002 1500 Z71 5.3L engine temp guage. And for the record the only mod I have is actually I have two. Dual Sport SS Gibson Exhaust
and a loud a@$ horn.

 

[ygmn]

What does engine temp gage drop to?

 

[jakeass0]

Yesterday when I would start up truck after it was already running for a while it would register about 180 or so and after 5 sec it would drop to the lowest setting of about 160.

This morning it moves up but only to 160. Even when I drove it for a 1/2 hour still only registered 160. When you turn off the truck it drops just below the 160 mark.

 

[WCFields]

Could the Thermosat be stuck in the open position?

 

[jakeass0]

Could anyone tell me where the engine temp sensor is located?

I went to look into the stat sticking when I turned the key over the temp is reading normal again but only for a few seconds before it drops back to the 160. This is without the engine even runnning. So, the thermostat might not be to blame. But nonetheless, I'll check it out.

 

[WCFields]

Sorry, but Sperry should be right behind with his handy dandy specs & diagrams.

I believe your truck is still in warranty. That aside, it may be worth taking it in to let them initially make an attempt to correct. If they can't, and you do, it will be noted in the service history and available for challenge if something fails later due to heating/cooling problems.

As for voodoo behavior, my old 92 Yukon had a problem with the oil pressure gauge. It would read about 5 lbs at idle and maybe 20 lbs at driving rpms. Immediately after an oil change it would get up to 30 for a few miles and then return to the above readings.

I had it in several times and was given the that's normal reply.

They guys that always changed my oil at a non GM facility finally noticed the low readings and ordered a new oil sending unit. No change. They messed with it over the years but never could get it to read correctly. There were never any problems with the oil pump or obviously related aspects, the gauge or sending unit line were out of whack.

 

[jakeass0]

ok guys. I checked the upper hose on the radiator and no coolant was flowing when I origianlly started the truck yesterday. So I don't believe the stat is stuck open.

Drove home last night and when I got there I shut the truck off and turned the key in the on position and the coolant temp guage had the correct reading again for a few seconds. I then put my OBD II code reader on it and didn't get any problem codes.

If anyone can tell me where this sensor is located I might just try to swap it out and see if it fixes the problem. It is just a thermistor, so hopefully it doesn't me a fortune.

 

[sperry]

I didn't see the year model, so I PRESUME It's in the same place.

Engine Coolant Temperature (ECT) Sensor Replacement

Removal Procedure

Notice

Use care when handling the coolant sensor. Damage to the coolant sensor will affect the operation of the fuel control system. ? HUH ?

1. Drain the cooling system to a level below the engine cooling temperature (ECT) sensor. Refer to Draining and Filling Cooling System in Engine Cooling.
2. Disconnect the ECT sensor electrical connector (1) .

 

[sperry]

3. Remove the ECT sensor.

Installation Procedure

Notice

Replacement components must be the correct part number for the application. Components requiring the use of the thread locking compound, lubricants, corrosion inhibitors, or sealants are identified in the service procedure. Some replacement components may come with these coatings already applied. Do not use these coatings on components unless specified. These coatings can affect the final torque, which may affect the operation of the component. Use the correct torque specification when installing components in order to avoid damage.

Notice

Use care when handling the coolant sensor. Damage to the coolant sensor will affect the operation of the fuel control system.

1. If installing the old sensor, coat the threads with sealant GM P/N 12346004 (Canadian P/N 10953480) or equivalent.

 

[sperry]

Notice

Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.[/B]
2. Install the ECT sensor.
Tighten

Tighten the sensor to 20 N?m (15 lb ft).

[
3. Connect the ECT sensor electrical connector (1).
4. Refill the cooling. Refer to Draining and Filling Cooling System in Engine Cooling.

 

[WCFields]

Thanks Steve, you found it!

 

[jakeass0]

Just got back from vacation the beginning of this week and I was searching for a sensor so I could replace it and see if it fixes my problem.

Much to my surprise after 5 days of sitting in my garage I start it up and go to work and everything is working fine. All guages reading properly and ac works great.

Thank you all for your help and I'll keep the diagram for future reference.