OVERHEATING ISSUES WITH MY MOTOR HOMEIT IS A MONACO POWERED BY A CUMMINS IT IS A SIDE RADIATOR MODELREPAIRS MADE TO IT SO FAR ARE AS FOLLOWS:RADIATOR HAS BEEN FLUSHED AND DIRT BLOWN OUT FROM THE OUTSIDE WITH COMPRESSED AIR RELIVING THE OUTSIDE DIRT.THERMOSTATS IN THE MOTOR HAVE BEEN REPLACEDWATER PUMP PRESSURE CHECK DONE. HYDRAULIC LINES THAT COME FROM THE HYDRAULIC PUMP AND ATTACH TO THE HYDRAULIC RADIATOR FAN DRIVE HAVE HAD THE LIMITER VALVE REMOVED AND THE FAN RUNS AT A FAIRLY HIGH SPEED.THERE IS A 50/50 MIX OF ANTIFREEZE.THE RADIATOR FAN BLADES HAVE A ADJUSTMENT ON THE FAN AND YOU CAN ADJUST THE BLADE PITCH ALLOWING MORE "PULL" BUT THIS OPTION HAS NOT BEEN PREFORMED.THIS HAS BEEN VERY FRUSTRATING AND I WOULD LIKE ANY ONES ADVISETHANKS

Could be the radiator has plugged cores and needs to be replaced or there is air in the system. Has it been blead properly. How hot does it get.

Faulty gauge.Rad too small in those cummins side rads..( known issue)Install bigger rad.Head gasket leak in coolant port..Dont run in overdrive or eco mod for trans...All I could think of...

I SUGGEST THAT YOU CONFIRM WHETHER THE TEMP GAGE IS ACCURATE, PERHAPS BY USING AN INFRARED LASER THERMOMETER.

While I don't have a side mounted radiator... several years back I had overheating problems, primarily on long or steep grades. The problem turned out to be two fold. An exhaust leak at the Turbo and a split seam on the charge air cooler. I'm not sure if it was one or a combination of the two problems but after the repairs were made I no longer had any cooling issues.

Yep! An exhaust leak to the turbo or at the turbo will cause it to overheat.

MONACO PUSHER 40' RADIATOR OVERHEATING | Good Sam Community

31 Replies

Mr_Mark1
Explorer
Jul 05, 2014
RayChez wrote:
Side radiators are like any other mechanical part, they can break. So instead of getting defensive on side radiators why don't some of you come up with an answer as to why this engine is overheating. We all know that the reason why some rear radiators were over heating. Now this person wants to know why his engine is over heating and he describes his coach as to having a side radiator. Who cares if it is a 1998 or a 2014. The problem is still there and all he is asking for idea's as to what it could be. GEEZ!

By the way side radiators are right behind the rear wheels and they do suck up a lot of dirt and grim that is kicked back by the wheels. This radiators are also hydraulic and could have a problem there. They are not perfect, they can give problems just like any other thing that is mechanical.

Well Ray, I see the OP stated what year his is. And, it does make a difference on what year it is. If it was a new 2014, we know it's not old hoses. Things have become more computerized from older units.

The more details a poster can give the better answers they will get.

Safe Travels,
MM.
conmoto
Explorer
Jul 05, 2014
06 330 ISC Cummins still have the slobber tube as I directed mine into a container.
JetAonly
Explorer
Jul 05, 2014
moondoggie2 wrote:
OVERHEATING ISSUES WITH MY MOTOR HOME
IT IS A MONACO POWERED BY A CUMMINS IT IS A SIDE RADIATOR MODEL
REPAIRS MADE TO IT SO FAR ARE AS FOLLOWS:
RADIATOR HAS BEEN FLUSHED AND DIRT BLOWN OUT FROM THE OUTSIDE WITH COMPRESSED AIR RELIVING THE OUTSIDE DIRT.
THERMOSTATS IN THE MOTOR HAVE BEEN REPLACED
WATER PUMP PRESSURE CHECK DONE.
HYDRAULIC LINES THAT COME FROM THE HYDRAULIC PUMP AND ATTACH TO THE HYDRAULIC RADIATOR FAN DRIVE HAVE HAD THE LIMITER VALVE REMOVED AND THE FAN RUNS AT A FAIRLY HIGH SPEED.
THERE IS A 50/50 MIX OF ANTIFREEZE.
THE RADIATOR FAN BLADES HAVE A ADJUSTMENT ON THE FAN AND YOU CAN ADJUST THE BLADE PITCH ALLOWING MORE "PULL" BUT THIS OPTION HAS NOT BEEN PREFORMED.
THIS HAS BEEN VERY FRUSTRATING AND I WOULD LIKE ANY ONES ADVISE
THANKS

You very likely have the same set up I do. Under what conditions does it overheat? Flat terrain at 70F? Pulling hill at 11000ft at 90F? What gear are you in when you overheat? What RPM do you operate the motor at? Are you towing?
CA_Traveler
Explorer III
Jul 05, 2014
Slobber tubes: Cummins told me that starting in 04 the slobber tube was guaranteed to not leak oil as it trapped the oil and returned it to the engine. The design change was obvious including the oil return line. This was a EPA requirement. Just information.
jtfcons
Explorer
Jul 05, 2014
The part about the limiter valve being removed doesn't sound right. This controls flow between the radiator fan and the power steering.

A few years ago I had a problem with overheating and increased steering effort. Spartan tech service had be check the function of the limiter valve but it turned out to be a bad hydraulic pump so I never got to the point of inspecting and cleaning the valve. Something else to consider.
Pogoil
Explorer
Jul 05, 2014
obgraham wrote:
GoldenHVAC: Where is a side mounted radiator going to get all this grime from that will be washed out? The slobber tube is nowhere near it.

All the dirt, hay and grass is thrown up from the rear wheels as the radiator is behind them it gets sucked in.

If you do not believe it wash out your radiator. When I do mine 2 times a year all kinds of stuff comes out. Just did mine and spent 1-1/2 hours to get the water clear running out.

I have seen many posts on the internet about side radiators running hot when climbing.

Pogoil.
CA_Traveler
Explorer III
Jul 05, 2014
BobR wrote:
Another potential cause can be a radiator hose collapsing and restricting the flow of coolant.
Another good thought with a 17 year old rig.

Do you know the history of any cooling maintenance?

BTW Some of the cooling system changes you described like increasing the hydraulic fan speed sound like someone is trying to mask the problem because they don't know what else to do.

Monaco tested their rigs in the Los Vegas area. They towed a dolly and could simulate any grade in the heat for any distance on flat roads. They had multiple instrumentation to measure the engine. My 2 Monacos never exceeded 204F on grade in 115F air with cab AC running. Just some information.
BobR
Explorer
Jul 05, 2014
Another potential cause can be a radiator hose collapsing and restricting the flow of coolant.
CA_Traveler
Explorer III
Jul 05, 2014
Have you taken the MH to a good repair shop that understands diesels and RV's?

Friends tell me that Massey's in Phoenix is excellent. I have no personal experience with them.

Click
wilanddij
Explorer
Jul 05, 2014
My neighbor just had overheating issues with his 2004 Dynasty, Cummins, side radiator. Bad thermostat, bad fan control board, radiators needed a professional steam cleaning.