BMT Forum Bot Posted July 19, 2009 Share Posted July 19, 2009 I have a 2007 CL733 with a 565 cummins eng. I changed the thermostat but still have a problem with coolant boiling over in the radiator.View the full blog entry Quote Link to comment Share on other sites More sharing options...
Bollweevil Posted July 19, 2009 Share Posted July 19, 2009 Engine controls have changed greatly over the past decade. When trouble shooting any problem, we are still required to go back to the basic problem solving question. Whats on, when, and where? Also a general knowledge of the system, or subsystem is essential. The basic cooling system is simple. It consists of radiator, with cooling fins, water pump, to move the coolant, a system of hoses and passages to deliver the coolant to where it is needed. Then it get's complicated. What happens when the radiator capacity to radiate, or transfer engine heat to atmosphere is exceeded. Then we need a fan. The next problem is how to drive the fan. A belt still works good on a truck, if it is adjusted properly. Do we need a fan all the time? Nope that's too simple. The fan robs horsepower, so now we need a fan clutch, either viscous, engine oil pressure operated like the old Rockford, or air operated like a Horton. Management of either system, other than viscous creates another challenge. We can operate it with a solenoid, but that brings us back to when and where. We could use a rocker switch or toggle switch mounted on the dash, but n reality that is too simple. It requires an operator to pay attention. A water temp sensor mounted in a coolant passage in the head or water rail works, but is often further complicated by the addition of system shutdowns incorporated into it. I don't know if it is already being done, but it could be controlled by the on board computer in late model trucks. A diesel engine. like a race engine will perform better and more efficiently as it gets close to 200 degrees F. With new emission requirements, engines are operating a lot closer to the edge. You didn't say what you do with your truck, or when it acts up. Make sure the radiator is is not impacted with bugs or mud, and that the fan clutch is working properly. You can check for circulation problems by shooting top and lower tanks with a heat gun when it is overheated. Or just touch each tank, if one is a lot hotter, you might have a bad pump. Quote Link to comment Share on other sites More sharing options...
ccllmm2008 Posted August 19, 2009 Share Posted August 19, 2009 I have a 2007 CL733 with a 565 cummins eng. I changed the thermostat but still have a problem with coolant boiling over in the radiator.View the full blog entryThanks for the reply Boweevl. Since the last time on here, two different Cummins dealers have replaced the head and yet another EGR cooler on the engine. I am now in Tenn and have the same problem once more after we have spent close to $7k now. What is going on with this damn engine? Quote Link to comment Share on other sites More sharing options...
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