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Spooky · 02-08-2008, 12:45 PM

Our 02 Journey 36DL with 35K has developed an overheating problem at highway/interstate speeds when on an incline. We pull a trailer and all weights have been verified as being within specs. I believe the fan pushes the air through the radiator which implies that hot engine compartment air is being used to cool the radiator fluid - that seems wrong from an engineering viewpoint. It seems that if the fan pulled the outside (likely cooler air) through the radiator, it would work more efficiently to cool the coolant and lower engine operating temperatures. Any ideas?

Spooky · 02-08-2008, 12:45 PM

Our 02 Journey 36DL with 35K has developed an overheating problem at highway/interstate speeds when on an incline. We pull a trailer and all weights have been verified as being within specs. I believe the fan pushes the air through the radiator which implies that hot engine compartment air is being used to cool the radiator fluid - that seems wrong from an engineering viewpoint. It seems that if the fan pulled the outside (likely cooler air) through the radiator, it would work more efficiently to cool the coolant and lower engine operating temperatures. Any ideas?

Ecker · 02-08-2008, 01:24 PM

Several questions. Have you cleaned radiator and charge air cooler annually ?? Are you maintaining 2000 RPM when climbing an incline ??

Spooky · 02-08-2008, 02:23 PM

Hi Leo:

THANKS for your response. YEP, I've done most all the maintenance and service items everyone else has commented on. Downshifting to 4th and maintaining 2,000rpm has helped immensely to keep the temp in the "Normal" range. The way the coach is geared, 65mph in 6th is 1600rpm, which makes the unit run "hot" when pulling long highway inclines, not hills. 5th gear results in 1950rpm and that makes a difference in engine temp as well as fuel mileage reduction. Maybe, it is just an accepted tradeoff as I have had 7 RV's and this is my first diesel pusher. THANKS again.

Ecker · 02-08-2008, 02:54 PM

You need to raise RPM to 2000 range on inclines in order to keep fan speed up and get proper cooling.
The air to cool engine is sucked from under coach and over engine then out CAC and radiator. A lower RPM on fan reduces the cooling at exactly the wrong time. The CAC and radiator needs to be cleaned with a good detergent and high pressure water at least annually. If not done all ready, need to ensure blowby piping is routed beyond the air flow so it does not go through the CAC and radiator.

Spooky · 02-10-2008, 02:53 PM

THANKS - crawled under unit and observed dirt caked on interior face of radiator. Have scheduled rad pull out and dip cleaning. This may be expensive, but should correct problem. THANKS again.

rex · 02-10-2008, 07:34 PM

Spooky,
There is no need to pull the radiator in order to clean it. You can do the job yourself if you want to. Get a garden sprayer and mix some Simple Green with water and spray the radiator from the engine compartment, and then outside also. Let it sit for about 15-minutes then hose it down with a garden hose. (Using a high pressure sprayer can damage the radiator fins)
Now after you think you have flushed it well, start the engine and run it at about 1000 RPMs for a couple of minutes to blow out the radiator. Now do it all again, and again until it is clean.
Yep, it's a dirty job, but somebody has to do it.