The truck has been running great lately. Now all of a sudden i can't even pull a small chipper behind me and it gets to 220-240. I have to pull over shut it off and let it cool. I don't know whats going on. Thermosat is new. Coolant was just replaced. also it is flashing code 18. Pump timing anyone know how to adjust the timeing??? Thanks for the help ahead of time

Pump cam reference pulse error. I would think that's the injection pump. It seems to run best to the right (advanced) than to the left (retarded).


The overheat problem could be as simple as a new radiator cap. Is your cooling system leaking anywhere? Pressure keeps the tempature low (185-195 deg.).Edited by: quantum mechanic

i will try the radiator cap. When it gets hot and i shut it off i can a a gargleing from the radiator fill area. Do you know how to adjust the timing. on the 6.5s

First thing I would look at is the thermostate. Take it out and put it in a pan of water and bring the water to a boil. The stat should be fully open just as you see bubbles in the water. New does not mean good.


If your cap was bad you should be seeing a lose of fluid in the reserve tank. I always mark the side of the tank after any change to the system for referance.

ok i will try the thermostat. The low fluid light comes on once and awhile and i smell anti freeze? I am not going to get to do this unitil tommorow but i will try both

You can tell if the themastat is working by watching the tempature guage on the dash. The truck should warm up quick ( within minutes) and come to a running tempature with in the firt few minutes of driving. the overheat may not be related.


If you hear pressure leaking from the radiator cap area the cap or a rotted hose/loose fitting is letting it out. Without normal running pressure you just boil off your water/coolant and the truck runs hotter.


Where do you smell the antifreeze? Its probably where it's leaking. When the heater core goes you smell it in the cab.


The coolant sensor gets air trapped in it ( the sensor in the hip to the left on the alumnum heater hose/theramstat crossover) and will be seen until you get it worked out, usually right after you get it to hold pressure.


Look at the rubber gasket on your radiator cap. If it's dry rotted, buy a new one. You can get one for under $7 at auto parts.





I use a 15 mm self ratching gearwrench and I have just enough room to turn the three bolts that hold it up against the engine. It cost me about $10 for the one wrench..Edited by: quantum mechanic

well I replaced the cap and bypassed the heater core. Thats where it was leaking. I has been doing great but it still likes to get up to 210 and hover there for a while. The thermostat is good so i am not sure what is going on. I pressure tested the system and it held>????? Would a leaking head gasket cause it to overheat. There is a smell of oil when you get near the exhaust pipe. And it blows alot....i mean alot of white smoke at start up. All This has happened int eh lawst two weeks

Keep an eye on your coolant level to see if it's going down And the other on the oil to make sure you don't start seeing water in it. When the head gasket goes the fluids will go into each other and sometimes into the cylinders.


What RPM do you idle at? When tempature sensors are acting up the RPM and running tempatures rise.


.and as HowieE said it could be the new thermastat you put in sticking.


Edited by: quantum mechanic

I would pull the raditor take it to a shop and have it cleaned and checked and clean out all the acumlated stuff between the raditor and AC condensor. If you have never don it you will be suprised how much stuff you can get in there. Some fellows clean between the AC and raditor every year just to be sure.

AceStump...


I had a problem with my 6.5, it was overheating often as well. found out my head gasket was cracked and pressurizing the cooling system. a simple test.. shut off engine, let it cool down, open the rad cap to realease any pressure. squeeze the rad hose to comfirm this, close the rad cap again. Start the engine and check the rad hose for pressure, if pressure builds up within seconds would perhaps indicate a problem with head gasket.


hope this helps