Diesel Sprinter Forester 2401WS Overheating

[JOhn_R_C]

I've got a new (4000 miles) Sprinter Forester and I'm having overheating/hot running issues under pretty extreme conditions (though everyone else seems to be running OK). I'm pulling a 3100# toad on a 200# dolly, well within the 5000# allowed.

First overheat was in Canada's Glacier NP in a construction zone. Stopped and cooled down for 1/2 hour, checked coolant and oil, all seems OK. Had to go over the hill in limp mode as I overheated again with nowhere to stop. Unit cooled right down on the downhill.

Coming through Spokane, WA in traffic and coolant temp got up to maybe 240F (limit is 250). Manually shifting to keep revs up to help the fan cool. Got to Coulee City in 100F temps and encountered an overheat and limp condition getting to the top of the hill to the campground and immediate cooloff on the downhill side, even with the heater on full and again manually shifting. As I said, oil and coolant both seem fine.

Are these 3 liter Diesels undercooled for their assigned task, or is there something likely wrong causing excessive coolant temps, or am I expecting too much from this rig. I downsized from a couple of Cummins RAM Diesels and fifth wheels and never had any cooling issues other than now in 14 years of RVing.

Thanks for your input.

John C

[JOhn_R_C]

Further to this post, I did about a hundred mile run without the toad. Temperature seemed to hover around 190 as a minimum and 212 was seen regularly with a max of maybe 230 briefly. Looks like my wife will be driving the toad until I can get to a MB dealer and get the fan clutch and control checked out .

[JOhn_R_C]

Appointment with MB of Seattle, WA Monday morning to address. Sounds like it will get hot enough to demonstrate the issue. Will advise of the outcome.

[JLeising]

Similar thread in Mercedes Sprinter sub-forum:
http://www.forestriverforums.com/for...wn-165966.html
FYI

[JOhn_R_C]

Thanks for that. Read the thread and made it to MB Seattle and they will look at it today. Will post results when fixed. Don't think I have issues discussed in that thread.

[JOhn_R_C]

Thanks to MB of Seattle, WA for getting me in on short notice and finding the problem. The fan was defective, probably from new. The service ticket is reproduced below:

"Client states vehicle is overheating. Coolant level looks good. When driving on freeway doesn’t seem to be an issue. Slower speeds and under load vehicle overheats.
FP Coolant fan
Found check engine light off at time of service. Idled vehicle in stall for half an hour to monitor coolant temperature. Found unusually high coolant temperatures (approaching 210 F at idle). Pressure tested cooling system and checked for leaks, found system leak free. Connected battery maintainer and SDS, ran quick test, found no relevant fault codes. Attempted actuation of coolant fan via XENTRY, found fan stays at 300-350 RPM regardless of duty cycle selected. Checked power and signal lines to fan, found OK. R&R cooling fan, again attempted actuation via XENTRY, found fan ranges from 1000 – 1800 RPM with duty cycle increase, fan operating properly at this time.
Damage 0 2030173 Auth#4873746
Labor ops 20-5630-03 54-0650-01
Parts FP Number 000-200-99-23 Fan"

John C