[hoot]

Had to replace my thermostats this weekend.

Very easy job.... After the first time and you know what's involved... it's a half hour job.

Reason... truck would not warm up and would sometimes drop to stone cold on the highway with outside temps at 38-40 F.

Now it's normal again. Getting the cooling system purged is a pain.

 

[White Duramax]

Hoot, did ya make a do-it-yourself article on it?

 

[hoot]

Hoot, did ya make a do-it-yourself article on it?

I would have loved to but this weekend was so busy I was lucky to even get the parts.

Here's the procedure....

Drain cooling system partially.... about one gallon.
Remove bleeder screw in tstat housing to aid in draining.

Remove engine cover (plastic)

Remove small bracket in housing and unclip two wire harnesses from it.

There are four bolts holding the housing in place and two on the end of the large steel pipe under the big computer harness connectors (where Juice plugs in).

Remove these six bolts.

Lift housing

Replace thermostats.

Re-assemble.

NOTE: The two thermostats are different. The one with the two vents in it goes in the rear port with the two vents oriented rearward.

There is no housing gasket. The t-stats come with their own oring type gaskets.

 

[JEBar]

Hoot ....


How many miles were on your truck when you found you needed to change your thermostats?


Jim

 

[hoot]

Hoot ....


How many miles were on your truck when you found you needed to change your thermostats?


Jim

I began to have strange things going on with my heat/defrost staring some time in the summer. I remember going down to OBX at 2AM. Windows started fogging. I turned on the defrost to get them cleared and olnly got cold air. As cooler days approached I noticed the heat wasn't up to snuff. I figured it's time to change the cab filters. Then suddenly coming home from work last week cold air started coming out of the heater. I then noticed the engine temp dropped to 160. Then it fluctuated.

When I got home I was spitting coolant out the overflow. Apparently the fluctuating temps do a number on the pressure balance..... oh forgot to mention... the whole cooling system was open during the stint at the body shop... for the tree damage. I figure I had air in the system too.

So problems started about 58,000 miles. I have 62,000 now.

 

[gwmayes]

There were a bunch of us early '03 folks that found out we got a bad batch of 'stats. Replaced mine with less than 2,000 mi. Just wouldn't heat up above 160 or so.