this will probably sound silly, but what is the purpose of changing to the 203* t-stat.

 

I'm pretty sure it just changes the running tempurature to a level that your engine likes better... 203* don't know much more than that

 

My gauge runs in the middle now instead of barely in the N-O-R range of NORMAL.
I now hit R-M range and stay there. This must be the 200 degree spot.
Veggie oil likes it. I am just wondering how summer will go.

 

Read this... excellent write up
http://www.dieselsite.com/index.asp?...ROD&ProdID=186

-Robb

 

I put a 203° thermostat in three years ago. I notice no changes in the hot temperature operation.

That includes pulling with a 16k GCW up the grapvine in August.

 

Really, what does your factory gauge run. I am hoping to get a normal water temp. gauge in shortly but for now what range of the normal do you run at what ambient temp.?

 

Remember that the factory gauges are idiot lights.

 

yeah but they aren't variable are they?
Meaning if he is running a certain temp and his factory gauge reads somewhere I should see the same temp at the same spot in the factory correct?
Or is it like the oil pres. anything over 5 psi and the guage kicks up?

 

It only took me 30 minutes to put a good gauge in the truck and I work slow without the mechanical skills you guys have. If you have an old failing thermostat in your truck, replacing it with a 203 will make it run better than new. One factor the PCM uses to adjust fueling is the engine oil temp, which correlates with the engine water temp.

 

I bet they are variable, but I dunno, maybe someone chime in it.

 

I am guessing variable. I can look at my idiot gauge as the truck is warming up and tell you when I hit 160 degrees on the temp gauge hooked to a thermocouple in my water pump.

 

thanks.
By the way. where do you hook up your water temp gauge? I am going to get one and put it in.
Fletch

 

If you look at the water pump housing, just below and to the left of the thermostat housing, you will see a plug. You can unscrew it and use that port. I do not remember the size, but the gauge I bought had various brass adaptors that came with it. I took some nippers and cut through the metal gauge mount that came with it so I could just loosen a screw holding some of the dash cover on and slip it in.

 

The oil pressure is a idiot light. They use a pressure switch with a resistor to make it go into "normal" when the switch closes.

The temperature gauge is an actual gauge. Mind you not a particularly accurate nor repeatable gauge, but a gauge none the less.

 

This link is a diagram to something cool I picked up here...you can do one gauge and two sensors with a switch that changes oil temp to water temp.. I'm just looking for a gauge that doesn't say "Oil" or "Water" on the face. Fashion over function...not really my nature.

http://good-times.webshots.com/photo/2360443840102203982aVsCov?vhost=good-times

- Ish