I just bought a 250 diesel and the stock temp gauge seems to read very low. Its about an 1/8 inch above the coolest running temp reading. All my gassers normally run about 1/2 way to red (right in the middle of the gauge). its not too cold here, about 0- 10C, and the gauge is always in the same spot. Is this normal running temp or do I need a new thermostat?

 

Mine runs right in the middle all the time no matter if it's freezing cold outside or blazing hot (Texas hot). This is once it comes up to operating temp.

 

What year is it? The older displays do not show in the middle, they show in the normal operating range about a 1/4" over the lowest point in the operating range. These gauges in these trucks are pretty much fancy looking dummy lights. Your sounds correct if it is an 99-01.

 

Probably a bad temp sending unit if it never shows it warming up. Does the engine seem to be a "normal" temp after it's been running a while? If it seems cool, it's a stuck open thermostat. When I bought my truck, it was doing the same thing. The dealership replaced both the sending unit and the thermostat. Now it runs in the middle of the range after warmup.

Joe

 

Yeah, thanks. I thought mine was a little odd, I'll look into a thermostat.

 

Its a 2000. The engine seems to be warm enough, but the gauge reads a low running temp, like john311t wrote. I'll check the sending unit too.

 

So its ready in the operating range, but only like a 1/4 inch above the low part of its range? Mines always done that and every ones i have seen that has the old display reads the same.

 

Does it move at all? Mine didn't...

 

No it doesn't move at all, and yes it is in the lower 1/4" of the normal range. I guess that's normal, I just thought it was a little strange. Well, happy to hear I don't need to do anything, it worried me a bit.

 

ya mine once it gets warmed up runs about 1/4 inch up and never moves even while towing in the mtns it dosent move, have never thought about it egt gauge is good to have

 

mine starts at the bottom when cold moves up to that spot and stops. I did have it move before when my radiator was full of mud. It was at the normal spot for awhile then i had to do a high speed sprint down the freeway at 90 and i looked down and it was up towards the top of the normal operating range. After i cleaned out the radiator, it has never went there again.

 

I mean does it move from cold to the point it is sitting after warm up? Mine did not. It never moved at all no matter how long the truck ran, so I knew I had a problem. If you're saying it starts out at the bottom, then moves to where you're describing, then it's probably fine.

 

It starts at the bottom, from starting the engine cold the gauge reads cold. Then it moves up to the operating temp (1/4" in to normal), then stays there. So it sounds like it's fine.

 

Okay then you're good. I took it as it didn't move at all even after warmup like mine...

 

The factory gauge isn't much more than an idiot light in my opinion. I have installed an autometer gauge that is much better at showing temp changes.

If you only have the factory gauge, I recommend driving the truck for 10 - 15 mins before getting greedy with the throttle. That usually gets my truck up into the 160 or so range depending on the ambient conditions.