overheat issue

[ScottLowry]

Hello everyone I am new to the board. I have a problem with my 1992 Truck. Here are the specs on the truck



1992 Dodge 350 Diesel 4:10 gears 5-speed Detroit locker in the rear. Flatbed with electric over hydraulic dump. straight pipe, and pump tweak. miles?



I bought the truck a year ago. When I bought it the heat gauge would go up between 1/2 and 3/4 then come back down. It would search like this all the time. I thought it had a bad thermostat. A couple of months ago it started pushing water past the thermostat gasket. I had a new thermostat and water pump installed. (at the time I also had a new clutch, rear main, front main and case gasket installed). The truck continued to do the same thing on the heat gauge. Well last week it started pushing water again from the thermostat housing. I changed the thermostat again thing I had just got a bad one from the parts store. It's not pushing water anymore but the gauge is still going up and down. It will go to 3/4 then come back down to 1/4. I am going to install a different heat gauge to make sure the factory one is not lying. Has anyone here dealt with this problem before. I use the truck for towing and hauling a lot. I haul 4 ranks of firewood and pull another 4 with a 3k pound trailer. Total load is over 20k pounds (counting truck) The gauge acts the same loaded or unloaded. To me it sounds like a head gasket. But I don't want to do that work if I don't have to. I live close to St. Louis if anyone wants to take a look at it. I will gladly pay of course. Thanks Scott

 

[Madurski]

Did you buy a cummins or dealer thermostat? I bought one from Advanced and it used to do that. For some reason the thermostats sold by parts stores don't work as well as the cummins or dodge part. I think I purchased mine from the Cummins dealer and it stopped doing that.

 

[ScottLowry]

One came from a good parts store and one came from Autozone. All three acted pretty much the same.

 

[rlyons]

Get you a cummins thermostat. Most aftermarket will have a wide swing. It is normal though if you are loaded as the fan clutch will kick in at about 1/2 to 3/4 on the gauge and cool the motor down until the thermostat closes and warms it back up.

 

[ScottLowry]

Ok thanks. Do I need to go to a Cummings dealer or will the Dodge dealer be fine. Heat gauge will be in tomorrow. I also bought a new fan clutch that I need to put in. Maybe these things will work.



Thanks again Scott

 

[rlyons]

I would reccomend Cummins as the price will be better and the part will be a Cummins part, some dealer parts are not Cummins parts.

 

[Madurski]

I am pretty sure that I got mine at the Cummins shop (I can walk there from work). I seem to have the best luck getting the correct engine pieces when I go directly to them. Half the time the dealer ends up sending me there anyway for engine bits.

 

[TKingsbury]

I used a Cummins t-stat in mine, and it swings too. I don't remember the part #, but it will swing until I've driven quite a ways. It will even out after maybe 1/2 hour to 45 min. I've learned to ignore it. Once it's fully warm, it's rock steady.

Travis. .

 

[CAROLINA CUMMINS]

I have a new Cummins thermostat and it seems to do the same thing. First couple of cycles it will go all the way to the next to last mark, then fall to below the second one. After it's fully warmed up, it settles to just after the second mark.



Steven

 

[ScottLowry]

I installed a Cummins stat and a heat gauge. It holds rock steady at 180. I guess I learned a cheap lesson about using aftermarket parts. Thanks