98 K2500 Suburban thermostats, sending unit or temp gauge?

[jrsavoie]

I had the thermostats changed in the 98 a couple of years ago. It has only run at 160 degrees on the gauge since.
I do not know what the gauge was reading before the stat change as I don't drive the vehicle very often.

The guy did not use Delco stats as I requested. He used Napa 190 degree stats.
The Suburban had plenty of heat for the heater in the winters.
Is there any possibility that it is not the stats?

The original owner had the same problem as there was a dealer service call slip describing the problem in the glove box.
It didn't have any diagnostics or a repair slip withit though. It would have been under warranty at that time.

Any good way of checking the actual temp beofre I change the stats?

I do have a thermometer style temp gauge here. Is there a good place to install it temporarily?

I also have an infrared thermometer. But I'm not sure how much I trust it.

 

[Chevylover]

In my opinion, you should install 2 new RobertShaw Style 180°F T-stats (got mine from kennedy diesel) and then start from there. I Think they are the best you can get. 160°F is to cold for a diesel and in most summers with towing the 195°F is too hot. After changeing the t-stats, check the gauge. NORMALLY it should rest at 180°F normal driving and 185°F while towing with A/C on.
If it get still to hot you should try the "FAN CLUTCH MOD" (search here in the forum). Than the fan clutch could engage earlier. These both things are cheap or for free, so I would start there. Almost other things are a little more expensive. At least, you also could clean your radiator - it free also.

Cu,
Sven

 

[ak diesel driver]

if you get to the point of pulling the stats boil them with a candy thermometer and verify what temp they open at.

 

[96 OILBURNER]

Just shoot the thermostat housing with the infared gun. Most i have seen are pretty accurate.

 

[jrsavoie]

Thanks, I'll shoot it after I get the rear axle back together. That's another thread.

 

[jrsavoie]

The thermostat housing is at 180 degrees after a 15 mile drive with the temperature being 85 degrees.

I'll put in the 195 degree ACDelco's part number 12559336 that I have on the shelf.

The Suburban should surely have been up to temperature by the time I got home.