Community Forums

Gary8346 · 05-04-2014, 06:29 PM

It appears that what I have is a dual electric variable speed "flex-a-lite fan. It definitely blows hard when I turn it on. Could it be part of the problem?

Mike Canter · 05-04-2014, 06:30 PM

Gary, before you do anything go to either Walmart auto section or and auto parts store and buy 3-4 cans of spray Gunk Original Engine a Cleaner. Simple Green is not strong enough. Spray that Gunk into all the radiator vanes as much as you can do from both sides. Then after 5-10 minutes hose it out. Careful you don't use too high of pressure so you bend the vanes. This is a common problem on rear radiator motorhomes. The crankcase vent called the slobber tube sprays a fine mist of oil over the radiator do the dirt sticks to it and then it overheats.

ChuckNJ · 05-04-2014, 06:32 PM

My fan is stock and it makes a hell of a lot of noise I can't believe an electric fan would be sufficient.I am an auto and truck mechanic by trade and have used electric fans in some van applications and they never seem to help

Gary8346 · 05-04-2014, 06:32 PM

I found a brochure at
Monaco Coach - brochures
It has a lot of useful information.

crah · 05-04-2014, 07:58 PM

Quote:

Originally Posted by Gary8346

I found a brochure at
Monaco Coach - brochures
It has a lot of useful information.

Gary

There are many experts of the Diplomat on this forum. Don't throw money at it. The ISL 400 is a great engine. You mentioned it has electric fans. That is not a stock item, and someone removed the old fan originally. Ther is no way an electric fan is going to keep up with that engine. Unlike typical car or truck mods that covert the engine driven fan to an electric, there is no adequate substitute electric fan for you engine. You need to get your stock fan back back and hopefully all the hardware is still in place and the fan blade only removed. You can get a new upgraded fan from source engineering.

Gary8346 · 05-04-2014, 08:02 PM

From the front of the radiator (rear of the coach) it looks pretty clean. There is no way I could get any engine cleaner on the back (engine) side as it is completely obscured by shrouding, fans, etc. it would probably have to be removed to clean the whole thing.

Mike Canter · 05-04-2014, 08:14 PM

You can spray it between the fam blades onto the radiator from below and above. I have done it. Just protect your eyes with safety glasses when below. The idea of installing one of the updated fans is a good idea. My guess is the original fan was removed in an attempt to improve gas mileage.

crah · 05-04-2014, 08:16 PM

Quote:

Originally Posted by Gary8346

From the front of the radiator (rear of the coach) it looks pretty clean. There is no way I could get any engine cleaner on the back (engine) side as it is completely obscured by shrouding, fans, etc. it would probably have to be removed to clean the whole thing.

Gary

You can get it from the engine side through the bedroom hatch. That is the only way to do it. It's not easy but doable. There are many writeups on this forum on how to do it. The radiator will always look clean from the back side.

ChuckNJ · 05-04-2014, 08:25 PM

I have the same diplomat you buy a garden weed sprayer that you hand pump mix your simple green and get it from the bedroom hatch and lying underneath you can do it!

onechaddude · 05-04-2014, 08:40 PM

Quote:

Originally Posted by ChuckNJ

I have the same diplomat you buy a garden weed sprayer that you hand pump mix your simple green and get it from the bedroom hatch and lying underneath you can do it!

I do the same but I use simple green hd which is safe for aluminum. I also mix in some dawn dish washing soap. Dawn is great at removing grease.

Chad

nodine · 05-05-2014, 05:02 AM

Quote:

Originally Posted by Gary8346

It appears that what I have is a dual electric variable speed "flex-a-lite fan. It definitely blows hard when I turn it on. Could it be part of the problem?

We have the same coach with the ISL 400 and the stock fan. We have put 58000 miles on the coach and never had any overheating problems. We have cleaned the radiator a few times. There is something wrong with your coach and as others have said the radiator is not to small. If you only have the electric fan and not the original fan that is definitely a problem. As mentioned check out the Source Engineering fan and while you are in there clean the radiator.

Bob

Gorlininc · 05-05-2014, 06:10 AM

I drive the Rocky Mountains all the time. As my engine warms up I keep downshifting and go slower.
In my 330 cummins here is my guide
2nd gear. 25 MPH
3rd gear. 35 MPH
4th gear. 45 -50 MPH.
5th gets. Up to 64 MPH.
The idea is to make your engine work as little as possible up the steep hills. I've found even on a long shallow grade my engine will warm up so I just put it into 5th gear and hand temp goes down.

My rule is if my temp reaches 200 degrees I downshift. If it doesn't start to cool down, I down shift again.
The idea also is to creat cooling the engine by high RPMs. I keep it about 2000 RPM.
There are many inclines the rig can go easily go faster but the engine isn't getting enough cooling.

This all works for me very well
I hope this helps. Safe travels.

Rburian · 05-05-2014, 09:55 AM

I had a similar issue with my previous 2000'Dip. Could not believe the crude that came out during removal with low pressure steam and orange simple green used by a truck shop. All was back to normal after cleaning.

Bob B
2005 HR Scepter

Jeff753 · 05-05-2014, 01:57 PM

Quote:

Originally Posted by Mike Canter

Gary the ISC 400hp is generated at 2200 rpm according to the specs I found. Are you now saying it is an ISL motor? If so then peak hp is at 2100 rpm. So on steep grades you need to keep it in the 2000-2100 rpm area

I can find my max torque of 1050 at 1300rpm but I can't find my rated horsepower rpm? I got hot on i75 last year in northern Ky.
I've since started downshifting more and cleaned the rad. Will find out if that fixed it shortly.
Not to hijack the thread but what is the 350 hp on the 2001 ISC Generated at?

Jeff