Community Forums

Jrmy_brdlv · 06-01-2019, 12:59 PM

I have searched this forum, the internet, asked many mechanics and I am still bagging my head against the wall. I have a 1999 Fleetwood Southwind 32V with theFord 6.8L V-10 Triton. I have been having problems with it overheating for a few months now. I have tried everything I know to do and nothing has changed.

So here is the story.....In March, we were going on a family get away in the mountains. We were climbing a pretty steep grade and I noticed the engine temp was climbing just as fast. Hoping to make it to a pull off area we continued until I did not feel comfortable continuing. The temperature gauge was on the red and I had to stop in the middle of the road. I shut it off until it cooled down enough to continue. After that, I had to make serveral stops to make it to the top of the mountain to keep it from overheating again. Since that night it has continued to overheat, but it doesn’t have to be climbing any steep grades to do it. It seems like if I go over 60 mph it wants to overheat now. I can let it sit running for hours and the temperature stays steady as can be. I can turn the heater on and go around 50 mph on the interstate and it stays pretty good as well. The second I go over 60 or there is a strain in the engine it overheats. Most of the time if you floor it for a few seconds you can watch the gage go down a bit but that does not always work. Once it starts going up, it is hard to get it to stop.

Now here is what I have done to fix it.....I started with the obvious and changed the thermostat. No change....Then I thought that maybe there was some air trapped in the cooling system causing cavitation. So I bought a cooling system refilling kit that sucks all the air from the system and replaces it with coolant to purge the system. No change.....I also tried using the T-fitting connected to the heater core hose to purge air. No change.....changed water pump, radiator, and clutch fan......No change....have changed/checked hoses as well. I am using a scan gage the check the temperature while driving to make sure the factory gage isn’t giving false information.

Is there anything that I am missing? Any advice? Has anyone else ever got this far with an overheating problem only to see that nothing has worked? Reaching out in desperation now. PLEASE HELP!!!

Russ Silber · 06-01-2019, 01:06 PM

Quote:

Originally Posted by Jrmy_brdlv

I have searched this forum, the internet, asked many mechanics and I am still bagging my head against the wall. I have a 1999 Fleetwood Southwind 32V with theFord 6.8L V-10 Triton. I have been having problems with it overheating for a few months now. I have tried everything I know to do and nothing has changed.

So here is the story.....In March, we were going on a family get away in the mountains. We were climbing a pretty steep grade and I noticed the engine temp was climbing just as fast. Hoping to make it to a pull off area we continued until I did not feel comfortable continuing. The temperature gauge was on the red and I had to stop in the middle of the road. I shut it off until it cooled down enough to continue. After that, I had to make serveral stops to make it to the top of the mountain to keep it from overheating again. Since that night it has continued to overheat, but it doesn’t have to be climbing any steep grades to do it. It seems like if I go over 60 mph it wants to overheat now. I can let it sit running for hours and the temperature stays steady as can be. I can turn the heater on and go around 50 mph on the interstate and it stays pretty good as well. The second I go over 60 or there is a strain in the engine it overheats. Most of the time if you floor it for a few seconds you can watch the gage go down a bit but that does not always work. Once it starts going up, it is hard to get it to stop.

Now here is what I have done to fix it.....I started with the obvious and changed the thermostat. No change....Then I thought that maybe there was some air trapped in the cooling system causing cavitation. So I bought a cooling system refilling kit that sucks all the air from the system and replaces it with coolant to purge the system. No change.....I also tried using the T-fitting connected to the heater core hose to purge air. No change.....changed water pump, radiator, and clutch fan......No change....have changed/checked hoses as well. I am using a scan gage the check the temperature while driving to make sure the factory gage isn’t giving false information.

Is there anything that I am missing? Any advice? Has anyone else ever got this far with an overheating problem only to see that nothing has worked? Reaching out in desperation now. PLEASE HELP!!!

Sounds like a bad sensor not turning fan on. Change out sensor. Might buy electric fan for cooling radiator and switch it so you can turn it on from inside. Not a big deal until good mechanic can figure it out.[emoji22] [emoji29]

Russ Silber · 06-01-2019, 01:08 PM

Quote:

Originally Posted by Russ Silber

Sounds like a bad sensor not turning fan on. Change out sensor. Might buy electric fan for cooling radiator and switch it so you can turn it on from inside. Not a big deal until good mechanic can figure it out.[emoji22] [emoji29]

Are you using ford thermostat? Some after markets dont work well. Try taking tstat out and run that way.

450Donn · 06-01-2019, 01:40 PM

Rus may have hit it first time. Get rid of the power robbing fan and add a pair of electric fans. BTW how long have you owned this MH? Is this a new to you MH? Also a professional flush of the cooling system may help. Be sure to down or more right upshift to a higher gear to allow the motor to rev and not lug.

Podivin · 06-01-2019, 01:55 PM

Quote:

Originally Posted by 450Donn

Rus may have hit it first time. Get rid of the power robbing fan and add a pair of electric fans. BTW how long have you owned this MH? Is this a new to you MH? Also a professional flush of the cooling system may help. Be sure to down or more right upshift to a higher gear to allow the motor to rev and not lug.

I believe you actually meant down shift to a lower gear - to allow the motor to rev.

twinboat · 06-01-2019, 02:12 PM

Don't run with out the thermostat.

Did you install the bypass type thermostat it calls for ? You need to, if you didn't. It directs the water thru the right passages.

At 50 MPH, you don't have a fan problem so electric ones won't help.

Look between the radatiors for debris buildup.
Open the radatior cap and look for blockage in the core tubes. Corrosion in the tubes slow the flow thru it.

Feel the lower hose for the spring that keeps it from collapsing. Could have rusted away.

Last thing is a combustion in coolant test kit. Bad head gasket can cause that and overheating.

Jrmy_brdlv · 06-01-2019, 04:05 PM

Quote:

Originally Posted by Russ Silber

Sounds like a bad sensor not turning fan on. Change out sensor. Might buy electric fan for cooling radiator and switch it so you can turn it on from inside. Not a big deal until good mechanic can figure it out.[emoji22] [emoji29]

The motor has a clutch fan, not electric. So if the sensor was bad it has no way to turn fan on. Correct or am I wrong??

Jrmy_brdlv · 06-01-2019, 04:09 PM

Quote:

Originally Posted by Russ Silber

Are you using ford thermostat? Some after markets dont work well. Try taking tstat out and run that way.

I am using the OEM thermostat with the bypass on it. Why do you think that the thermostat would work great while sitting still for hours but not work well over 60 MPH?

Jrmy_brdlv · 06-01-2019, 04:14 PM

Quote:

Originally Posted by 450Donn

BTW how long have you owned this MH? Is this a new to you MH?

I have owned it for over a year. I have tried to go into the hills with higher and lower rpms and neither have helped much. It definitely does make sense to keep them higher so the fan and coolant are flowing better. Wish that fixed it, but hasn't worked yet.

Murf2 · 06-01-2019, 04:17 PM

Quote:

Originally Posted by Jrmy_brdlv

I am using the OEM thermostat with the bypass on it. Why do you think that the thermostat would work great while sitting still for hours but not work well over 60 MPH?

Well, because the harder you work the engine the more heat it throws off.

I would suggest checking the radiator condition inside & out, as mentioned above. Probably best to just remove it & take to a radiator shop.

The other thing I would look at is possible exhaust restrictions. That can do some odd stuff.

Good luck!
Murf

Jrmy_brdlv · 06-01-2019, 04:18 PM

Quote:

Originally Posted by twinboat

Look between the radatiors for debris buildup.
Open the radatior cap and look for blockage in the core tubes. Corrosion in the tubes slow the flow thru it.

Feel the lower hose for the spring that keeps it from collapsing. Could have rusted away.

Last thing is a combustion in coolant test kit. Bad head gasket can cause that and overheating.

When I replaced the radiator I checked for debris. It was clean. I can only check the overflow reservoir, which I replaced as well.(forgot to add that part) I do have the lower radiator hoses on order and should be here this week. The upper was just replaced.

Wouldn't a bad head gasket cause it to overheat even when sitting idle? I am also not losing any coolant.

Jrmy_brdlv · 06-01-2019, 04:21 PM

I did forget to mention that I also replaced the coolant overflow reservoir. That is the only way to put coolant into the radiator (in case some people don't know that). So that also means that the cap to the tank was replaced.

Jrmy_brdlv · 06-01-2019, 04:30 PM

Quote:

Originally Posted by Murf2

Well, because the harder you work the engine the more heat it throws off.

I would suggest checking the radiator condition inside & out, as mentioned above. Probably best to just remove it & take to a radiator shop.

The other thing I would look at is possible exhaust restrictions. That can do some odd stuff.

Just replaced the radiator, so it is brand new. I have not checked for or even thought about exhaust restrictions. Now that you mention that, I did get a P0401 code the other week that said "EGR Flow Insufficient Detected". I will definitely check on that.

Thanks a lot!! That could be the problem!

tderonne · 06-01-2019, 09:06 PM

I was going to say it sounds like a fan clutch problem. But, you replaced it. Even though, do you hear the fan engage as the temp gets to the 205-210 range? There's no mistaking it. There are no electrical controls for it, it's a good old fashioned viscous clutch, it gets hot, locks up, and the fan spins.

(And to the comment about it over heating at speed so it can't be a fan issue, that's usually true, but not always. Before I added an airdam to my motorhome, the fan would come on driving on the freeway at 70 MPH.)

You also mention the scangauge, but you haven't mentioned any numbers. How hot is it getting?