Why Does My Toyota Odyssey Motorhome Overheat On Grades?

by Jewel

My '90- 22' Toyo-Odyssey heats up on steep grades when the weather is hot in California and Arizona. I do not drive with the A/C on, or water tank full. Do not overload MH.

I have replaced the Fan Clutch (3) times within last 3 years. The first time was due to overheating, second time defective fan clutch, last time fan clutch seized up in Canada. After repair drove all over Canada and Alaska pulling steep grades with no problem. Started up steep grade (Grapevine) started overheating, it was a hot afternoon. The radiator was gone through prior to trip. Could you help me.

ANSWER: Greetings Jewel thanks for submitting your question on our Ask An RV Question Page.

Since you state that you have had the radiator worked on and replaced the fan clutch we can eliminate those two items as a cause of your current overheating problem.

The overheating problem could be something as simple as a bad radiator cap or bad thermostat or even a pin hole leak in one of your radiator hoses.

On the more complicated and expensive side you could have a bad or leaking water pump, blown head gasket, cracked head. Besides the overheating a sure sign of head gasket problems is seeing white smoke (steam) coming out of your exhaust pipe especially when you are overheating.

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I am afraid that the only way of finding out for sure is by taking your Motorhome in and having a mechanic check all of the items I mentioned above.

Hope this helps.

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RVing Al

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Toyota MH over heating
by: Anonymous

I have owned a Toyota Winibago Toyo MH for three years (3.0 v6, automatic). Have always had over heating issue in summer. I travel mostly in Utah, Arizona and California. I am in the process of replacing the radiator with a 3 core copper radiator and installing a 3300 cfm electric fan. The electric fan should give me a few extra hp by taking the load off the engine and lowering the temp. I also am hoping for cooler air from the ac. Will report back on results in a couple months.

by: Anonymous

If you don't have a transmission fluid cooler you may want to consider one

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