I purchased my truck in June '07 with 79K. Took a trip and blew a hose in the desert and got hot engine lite and OEM temp gauge laying on the right side.

I changed the thermostat from OEM 195* to 203* from Dieselsite. Installed real live temp gauge and left OEM as well. Truck never has gotten hotter than 165, Oil temp 175-180, Checked it with an Infra red thermometer and it confirmed low temp.

Bob at Dieselmanor sent me a new 203* thermstat and now I can, with effort and hills get the temp up to 180, confirmed with infra red. I also discovered that my temp gauge is reading 15* low. (swapped it with the oil temp guage)

What do I need to do to get the old red rooster up to operating temp? If I lived where some of you guys do I can only imagine what my eng. temp would be. The coldest that it has gotten around here is 30* above.
Days have been in the high 60's.

If I recall TJ says his temp is in the 200's and it's cold there.

Comments??
Rog

 

hmm... I took my rig to work today and it was around 210-200 the entire trip.

My guess would be is to see what your running for oil temps. Ideally, those are the only numbers that matter. The PCM reads the oil temp if i remember correctly. Or you have to crude in the cooling system thats not allowing the thermostat to close properly?

 

My cooling system is clean as can be. I just replaced the stat again and had to drain the system in to a large plastic bucket. The coolasnt didn't have so much as a grain of anything. I also have a bypass coolant filter on/in the system.

I have never ever seen this truck over 180* other than when I blew the hose.

I would think that it's gauges except the inra-red keeps confirming the temp.

Rog

 

your fan is stuck engaged is it?

 

As c00n stated.
You could have drag in the clutch.

On the water pump lower hose connection.
Is the pipe connection bolted to the pump?
Or is it one piece cast alum?

Your coolant filter. How is it plumbed?

WAG is your coolant filter. Is causing the over cool.

Bill

 

The lower hose connector is bolted to the bottom of the pump, similar to the top inlet.

The inlet for the filter is "T'd" into the heater hose that comes off of the block just below the pass. head, (Pressure side). The return from the filter "T's" into the heater hose that connects to the top of the water pump.
(the return side)

I purchased the coolant filtration system from Dieselmann who has on his site diagrams of the proper plumbing for the system.

As far as the fan clutch goes it does not spin freely but is easily turned but feels like there is a drag on it.

I do not know how free the fan should spin but I think that you guys may be on to something.

Rog

 

Thanks Rog, I've been waiting for your response on the second 203 stat install. As I PM'd you we seem to be getting the same response on our beasts and I have a stock 97 with 195 stat, no extra cooler filter.. also used a thermo laser device and had about same readings as you do. I'm wondering if something with the water pump is not quite right, internal thing, when ya overheated ?

Know that's not much help though.

Jim

 

Did the coolant filter have a restrictor in it?
If it is an open filter (no restrictor) It will flow to much coolant.

Dieselmann's system comes with shut off valves. Turn them off and see the temp rises.

Bill

 

Bill, I've never saw a coolant filter .. can it really bypass enough hot coolant to create kawa's situation? Interesting ... does that mean the coolant is bypassing the thermostat through the heater hoses ?

 

Hussler:
The filter draws coolant out of the block and dumps it back in almost on top of the Stat. via the water pump. So I'm sure the filter in and by it's self is not causing me to lose 20+- degrees.

When I over heated it was not a drastic burn, I stopped immediatly and used hot water from the 5th wheel camper to cool it off. If it had caused something inside the pump to break or malfuntion I would think that I would be running hot not cold.

To answer Bill's last question I have had the filter turned off since I changed the stat. and it's still running cool.

I think that they hit on something re the fan clutch.

Rog

 

I doubt it, it's known fact the fan does very little to cool much above 30+ MPH. If the stat was doing its job then you could have a jet engine sucking air through the radiator and the truck would/should maintain temp.

Jim

 

Are you sure about the fan not needed above 30MPH? If that is true then the only fan needed would be a small elect. job when running through traffic.

I was running the hills on I-80 towards Reno just to get it to 180* Hmmmm
I know that the new stat is doing something as the OEM idiot gauge is leaning towards the right of center which is something that it has never done before.

Rog

 

When my fan was stuck, I could get the temps up to 180 going down the highway after quite some time. It seemed like it took forever to get it up to operating temp. Once I got it to 180 is usually stayed there, but after about 10 min of idle time it would drop to 170 or a little below.

 

Take the fan off to test it. Really the fan should make no difference in warm up time or operating temps. Thats the thermostats job.

 

Rog

What was meant is that when you refill the system the truck has a habbit to air lock the heater core with/without the coolant filter (short ckt). Just more with the filter. You might notice that every couple weeks the degas will look lower. Only by a small amount but enough to think you have a leak. You do not, its slowly pushing the air to the degas.
Air in the system upsets the temp. The cooling system is oversized and the PSD is efficient.
I had some what same issue as you state. It stemmed from altering the trans cooling. The cooling system wanted the heatload from the trans to help the motor. In summer i remove the trans fluid from the rad to reduce the trans temp. In winter i reinstall the fluid into the rad. Its a 15* to 20* swing.
The hand shakers run a little cooler from not having this. (short shifting like a auto would shift).

BTW - I run a horton clutch. My fan free wheels, with a modded t-stat (208/210). I use an aux oil cooler in warm temps.

Do the winter front thing and see how much of a rise in temp you can get.
Did you test the stat? I would test it first. Fully closed temp from full open is the important one.

Bill