Community Forums

stich · 06-12-2015, 09:03 AM

Just got back from a two week vacation and had a bit of a problem. We've had the MH for over 10 years and it has never gotten past the midway point on the temp gauge before. This trip started out the same but midway it started to run about 220* and a little higher on the hills. Never got to the red but still concerned that this may be the start of a problem. I have a 1998 with an M11 engine with side radiator. All service was done before trip and no problems detected. Where do I start? I realize that it could be a number of things but what is the most common and hopefully least expensive? I don't want to give the service man free range on my checkbook.

dons2346 · 06-12-2015, 09:32 AM

I would start by making sure the fan controller is functioning properly

deandec · 06-12-2015, 10:13 AM

Be sure the coolant level is proper.

Failing to burp the coolant system after replacing or adding coolant can leave an air bubble in the system that will force coolant out of the overflow tube.

stich · 06-12-2015, 05:40 PM

Well I did a search on posts about high temps and found a lot of good suggestions. (Should have done that before I posted) I have an appointment to have it diagnosed but in my mind, I believe that it may be a thermostat or possibly the controller as it came on all of a sudden with no warning or gradual increase in temp. Maybe the high speed fan is not coming on? We'll see next week.Hopefully not too $$$$$$$$

palehorse89 · 06-12-2015, 05:46 PM

I am going to guess the radiator is all plugged off with a lot of years of junk. You will not be able to see how bad it is till it is removed and the charge air cooler is taken off the front of the radiator, then you will see what I mean. It is near imposable to clean a radiator properly in the Coach. 17 years old.........needs cleaned I'll bet. Do a search on here and you will find others that had the same problems and was surprised how plugged off the radiator was when it was pulled. Here is one photo to show you what I am talking about........

stich · 06-12-2015, 07:37 PM

Quote:

Originally Posted by palehorse89

I am going to guess the radiator is all plugged off with a lot of years of junk. You will not be able to see how bad it is till it is removed and the charge air cooler is taken off the front of the radiator, then you will see what I mean. It is near imposable to clean a radiator properly in the Coach. 17 years old.........needs cleaned I'll bet. Do a search on here and you will find others that had the same problems and was surprised how plugged off the radiator was when it was pulled. Here is one photo to show you what I am talking about........

That doesn't look good. You may be right. A lot of years of use so it may look the same. Definitely will have to do the cleaning routine. Thanks for the visual.

deandec · 06-12-2015, 11:02 PM

Palehorse, was that a side mount radiator in the picture?

palehorse89 · 06-13-2015, 05:24 AM

Quote:

Originally Posted by deandec

Palehorse, was that a side mount radiator in the picture?

Yes it was, I have also seen rear radiator's that look just like that one if not worse also........
When I replaced my radiator a couple of years ago, I could not believe the junk, mud, rotten leaves, that was trapped between the radiator and the charge air cooler, mostly laying in the bottom radiator support, funny it did not rot it out. There would of been no way to know how bad it was as I had washed it from both sides really good several times, and one time with the engine running on high idle with the fan pulling inward while washing.........that is why I always post, that to properly clean and maintain your radiator(older Coach's) when doing a coolant change, take the time to pull the charge air cooler off to get to the radiator and clean it out good. If you do a search on here , you will find a lot of radiator stories just like this one with photo's and the end result is that they had to pull it apart to clean it properly. Its a bit of a job, but my engine runs right at 180 deg. with a very slight rise on a hard pull, maybe 190 deg. one time with the trailer on the back. My cooling system works like new.
Here is some good reading http://www.irv2.com/forums/f26/rear-...ng-163541.html

HoleInOne · 06-13-2015, 07:48 PM

Just went through an overheating problem so maybe I can shed some light on this.
First off T stats normally fail in the open position but still this could be the problem. Changing them is not a huge problem. Changed mine...still overheated
Fan controls normally fail in the high setting so I doubt that is the problem. Changed mine.....still overheated.
Third I am betting on the radiator. Mine was junk when they took it out. Was rotten enough on the inside that not enough water was flowing through. Do a simple pressure test on the radiator cap and this should detect the problem. Mine was fine until it reached maximum pressure then it started overheating. Would not hold pressure.
Good luck.