Radiator Fan

[Jerry Sanders]

Good evening,

Our coach has been on the road for almost 2 months without any heating problems.  Today we received 2 warnings, one for high temp on the trans (240) and two for the engine (217).  The temps start to rise whenever we start to climb and immediately drop on the down slope and hold at 190-200 engine and 203-212 trans on the flat.  I suspect the fan has stopped working.  What temp is required to start the fan working and is there a way to test the fan?  The fans turns freely by hand but I can't ever hear it running.  Any advice?  The coach is a 2000 Marquis, C-12.  We are returning home to California from the east coast and climbing the Sierra range is not possible with this problem.

Jerry

[Steve Huber Co-Admin]

Jerry,
Not sure  of the fan therrmostat setting but pretty sure that it should be running if the engine temp is in the 190+ range. You can slide underneath the radiator to see if it is running when engine is in the 190+ range. What did it run at before this problem? If fan is running check your antifreeze level. May have sprung a leak.
Steve

[Jerry Sanders]

Steve,  Thanks for the quick response.  The temp never went over 200 for the engine.  I suspect the fan due to the rise in trans temp.  The trans also never ran much above 200.  I'll climb under the coach after a short run tomorrow and check for fan activity.

[Gerald Farris]

Jerry,
The transmission temperature is closely tied to the engine coolant temperature on your coach because the transmission cooler is in the radiator hose. Have you checked the coolant level? If the fan is not working, the coach will overheat on a level road as well as on grades.

Gerald

[Edward Buker]

Jerry,

You could also have a thermostat that is not opening properly although the failure rate is quite low for these thermostats. You may want to use an IR gun and check the block water jacket, thermostat housing, and the radiator face temperature when your temp is overheating. If the water jacket and radiator are similar temps then the thermostat and water pump is probably working well and the air flow and fan may be the problem. If the fan is running and the radiator is cooler then the water jacket or the thermostat or water pump may be restricting flow. You might check across the radiator face for temperature variation  to see if a section of the radiator may be plugged. My assumption is the antifreeze level is adequately full. I know you will not have normal readings to compare to but you may be able to get some insight as to what may be happening.

Later Ed

[Jerry Sanders]

Well the problem has been solved......not very technical.  The fan is operational but it couldn't move enough air through several pounds of dirt, leaves and pine needles that were lodged between the air to air cooler and the radiator.  Removing all of the junk solved the heating issue.  All is operating at normal temps.  Thanks to all who made suggestions to help. The solution was very low tech!

Jerry

[Joel Ashley]

As an adjunct to this subject for those of us in Region 1, I understand that the often hard-to-find Extreme Simple Green for Motorsports is now available at Fred Meyer, although I haven't yet looked for it there.  I intend to the next time I'm in my local Freddie's.  

Previous threads on cleaning radiators have elicited the recommendation from the well-informed that regular Simple Green was not aluminum friendly, especially if not thoroughly rinsed off.  But Extreme Simple Green was just fine, and in fact one of the best options for radiator cleaning.

Joel

[LEAH DRAPER]

JOEL or Anyone
What is the difference between the "regular" and the "extreme" versions of Simple Green.  Do you know?

Leah

[Joel Ashley]

Hi Leah-

The regular Simple Green that most people are aware of has been known to react with aluminum, and I guess brass as well, but usually because it's not thoroughly rinsed off after cleaning.  As I understand it (forgive me if my memory is off a tad here), after accidents involving deteriorated aircraft parts, Boeing personnel were involved in the development of a version of the cleaner that was safe on aluminum even when some of it was inadvertently not rinsed very well.

Since Simple Green was used in industrial quantities for cleaning aircraft and parts, and was considered one of the best for the job, this was an important improvement, especially given the profusion of lightweight aluminum in airplanes.  Often listed as Simple Green Extreme for Aeronautics, or some such name, some auto parts stores and others sell what I deem to be essentially the same stuff called Extreme Simple Green for Motorsports.  

The airplane enthusiasts from Seattle in our club may add more insight here or correct any of my understanding, but since Extreme Simple Green dissolves and cleans gunk well and won't corrode the aluminum of radiators or sensitive engine parts if some doesn't get rinsed out of remote corners, it is preferred.

Joel

[Lee Welbanks]

Simple Green Extreme good to go with aluminum, brass, chrome or just about any metal. I grabbed the following off a add:

Extreme Simple Green is a cleaning and degreasing product that is extremely powerful, but doesn't harm the high-end surfaces found on motorcycles, aircraft, ATVs, sports cars, race cars, RVs, watercraft, bicycles, and more! Extreme Simple Green meets compliance standards for Boeing spec D6-17487P, ensuring safe usage on aircraft surfaces.