Hey guys,

My uncle is a devoted 1st gen CTD fan and the proud owner of an 89 much like the one in my signature except his has the Getrag 5-speed. He just had a pump rebuild and the valves adjusted on his truck and now it overheat. He put a new thermostat in it and it still does it sporadically. It might run fine for 20-30 miles and then it will just overheat out of nowhere. Any suggestions?

 

just throwing out the first thing that came to my mind...

when the pump was rebuilt maybe that advanced the timing... advanced timing causes more of the heat to be absorbed in the cylinder raising engine temps overall right? don't know that it would make it overheat like that, is it a ton more "rattly" than usual?

 

are u sure it is getting hot, or is it a gauge problem?

 

I am positive it is getting hot because when the guage reads hot you can shut it off and it is steaming. Yes the engine is excessively "rattly" and the mechanic that did the pump rebuild did advance the timing on the pump. So, you guys thing the pump may be advanced too much?

 

Hey all,

My uncle also said that the truck was smoking really bad when it is first started. Do you all think this points to the injector pump being advanced too far? Thanks alot!

 

I would find it hard to believe that the advanced timing would cause the described scenario.
I would suggest a couple things:
1) Easy enough to check, but make sure the rad fan is spinning, not sure if the '89 is a clutch fan or not. Faulty fan switches will cause you grief.
2) I've heard of new thermostats being faulty before. I know others from this site buy their thermostats right from Cummins, aftermarkets just don't cut it.
3) Does he use a front cover? If so...delete.
4) Not likely the cause, but make sure the rad exterior is clean and free from bugs etc.
5) Next time he starts to heat up, make sure he cranks up the heat in the truck to try and dissipate the excess.
6) Any leaks at all will cause loss of fluid and overheat the engine. Make sure to check hoses, clamps, or even better, use a pressure tester on the system.
7) Leaks from or around the pump can indicate a water pump failure.

Hope this helps.

 

I second that, if its full of coolant and fans working, is stare at thermostat