2007 Cushman truckster overheating issues Cancel The title field is required!

1. James Smith

   

   112 posts
   
   5/8/2015 3:05 PM

   We have a 2007 cushman truckster diesel that has just started overheating on us. We have already flushed the radiator and added new antifreeze with no luck, We have pulled the thermostat out with no luck, changed the engine oil and cleaned the motor off with no luck.
   
   Now I am at the fan motor. Does anyone know of a way to test the speed of the fan (amps) so we can tell if that may be the problem (they want $500 for the damn fan). So far we have been going through the process of elimination with no luck so I am hoping that one of you guys may be able to help me out.
   
   Thanks

   
   
   
   
2. Richard Lavine

   

   3 posts
   
   5/8/2015 4:05 PM

   When you say "flushed the radiator", are you referring to inside or outside? If you take the radiator out, look through the fins. You must be able to see clear through the fins to daylight on the other side. It is VERY easy to see how a radiator can accumulate mud, grass, and other debris. Good luck.

   
   
   
   
3. Dinger Greg

   
   5/8/2015 8:05 PM

   One of the best tools I own is a laser temp sensor. I would shoot both top and bottom hoses, at the rad, to verify efficiency. Also, I'd shoot both sides of the Tstat to verify its function, also, I'd check both sides of the pump to verify flow, although I've never seen one come apart without evidence. You can boil a Tstat to verify its function, out of the machine, if you suspect it.
   
   A head gasket that leaks combustion gas into the coolant will cause overheating in a minute. This would be evidenced by debris and bubbling in the coolant. A five gas analyzer would verify this, as would a combustion leak detector available from any auto parts store.
   
   Any chance the temp sensor is bad?

   
   
   
   
4. Henry Heinz

   

   0 posts
   
   5/9/2015 7:05 AM

   Use a cooling system pressure test gauge, it will tell if you have a leak, and there other test to verify a leaking head gasket or intake. Pick up a good one off a tool truck or NAPA, the little booklet will guide you through some of the testing procedures. Most think it's just for leaks, but it does so much more. Also without the thermostat in you should have consistent flow through the radiator from your water pump, if you see a lot of bubbles or backup/spillage through the fill area you most likely have a blown head gasket, cracked head, or block. If the fan is kicking on and turning with some force its most likely good. If it's not coming on it could be a switch or relay that is bad. You can use a power probe and check the voltage and then apply voltage to the fan to see if its working. With the thermostat in and over heating, just feel the top and bottom hose, if one is warm/hot and the other cold there is now flow through your system.
   
   Regards,

   
   
   
   
5. Bob Pruneau

   

   5 posts
   
   5/9/2015 10:05 AM

   Can you put power to just the fan to see if it's working .temperator activates fan at around 190 degre. If it works and doesn't engage fan look at the sensor at engine or relays . If it's not smoking white smoke / rad /oil fluids are not milky then the head gasket is most likely ok . Water pump working ?

   
   
   
   
6. James Smith

   

   112 posts
   
   5/14/2015 11:05 AM

   An update, I could not get a cooling system tester with a small enough adapter to fit our cushman radiator. So we pulled the thermostat and I watched the water boil out of the radiator then get sucked back down only to keep repeating this process. there were lots of air bubbles also. So we pulled the water pump to inspect it and found about a half inch of metal missing from around the port hole but this would of only allowed the water to recirculate and not leak out. Our next step is to pull the head as we are/were pretty sure that is the problem.
   
   The real issue we faced is finding the parts. Jacobsen had the ability to get me one but they wanted almost $700 for the water pump (I ordered it straight from China for $95), the head gasket kit I was able to locate at a Perkins parts site online for a little over $300 I did not even want to ask Jac for that price).
   
   I only have to wait 2-4 weeks for the part from china though.

   
   
   
   
7. Henry Heinz

   

   0 posts
   
   5/14/2015 12:05 PM

   If you do find its a cracked head, some NAPA machine shops can weld it back up and test it depend on where it is cracked at. JFYI, in case you want to check with a machine shop depending on your findings, as it could be just a blown gasket, but I'd have the head magna-fluxed at a machine shop and they can check to see if its warped or not and if so they can most likely resurface it for you.
   
   Regards,

   
   
   
   
8. James Smith

   

   112 posts
   
   5/20/2015 2:05 PM

   Henry thanks for the input. If I pull the head it will be Magnafluxed! No sense going that far and not do it right.