Overheating ISL400

[jleamont]

Did anyone check the lower radiator hose (engine return hose) to make sure it's not collapsing under load, from the suction?

Also check with Cummins-- could the water pump be spinning backwards, Some manufactures offer water pumps with reverse impellers, or did the new engine come with the water pump or was you old one transferred to the new engine? If you are reusing the pump make sure the impeller is tight on the shaft.

[manholt]

I had the same engine, same problem on a 07' Winnebago Tour 40KD...per Cummins, the coolant reservoir was to small. Changed it out and never had a problem

again...I do Hwy. 285 out of Ft. Stockton, TX. to Roswell, NM, every summer on my way to Ruidoso, NM. 107+ degree weather. I have been on Hwy.14 in CA, both

ways in Summer....like an oven.

[dean0283]

Well, finally received and installed a new fan motor. Took it out and ran up the hills, temp ran between 199 and 206. I could actually hear the fan go to high while driving. Hopefully the problem is fixed.

Disassembled the motor and the bushings and gear shafts were galled and out of round.

BTW, only took 4 months to receive a new fan motor.

Dean

[dickandlois]

Dean,

Thanks for the feed back!

Do you have the hydraulic cooling/fan motor? And did the shop flush out the system and replace all the filters?

Rich.

[dean0283]

Hi Rich & Lois,

Yes, replaced all fluid and filters before we ran the new fan motor. The fan motor is hydraulic.

I have replaced, I think, everything in the engine cooling system, including the radiator, various pumps and controllers, sensors, thermostat, hoses, clamps, etc.

Heck, I even had a new engine installed, not due to overheating. Engine had a factory defect and a recall.

Dean

[dickandlois]

Dean,

Thanks for your information!

I had to go back to your first post where you mentioned having a new engine with just 12,000 miles on it when the heating issue came up.

Now you get to replace it again, under warranty. Hopefully the third engine is a charm. Just not a common to replace an engine twice!

Did they give you any thoughts as to why your experiencing, what appears to be a continuing cooling problem?

Maybe you could get a stipend and be an engine field test engineer, supply you with there OEM software and test equipment so you could file monthly engine readouts in a real world application.

Good to hear they have been willing to work with you on this issue.

Rich.

[dean0283]

Hi to all,

Well, I've taken a long trip, down the central valley of Ca. Up hwy 58 (from Bakersfield to Barstow) I40 to Flagstaff. The air temp was pushing and above 100°. You all know how steep I40 is and my engine temps never exceeded 206°. My readouts ran between 199 and 206.

I pull a Chev. Tahoe that weighs about 5600 lbs. It seems my problem is fixed. Now all have to do is relearn how to drive without one eye on the temp readout and the other on the road.

Amazing how well I see with both eyeballs on the highway.

Thanks for the tips and for hanging with me throughout this ordeal.

Dean

Thanks

[manholt]

If we ever hear from Dean again...here's my 2 cents worth!

Had the same problem on a 07' Winnebago Tour 40KD with a 400 Cummins and rear radiator. Turned out to be the coolant reservoir that was too small. Cummins gave me 2 choices, I could change it out for the correct size or add coolant as needed for the heat of summer, I choose to look at my level in the mornings and add as needed. Also, when temps. in far West Texas and East New Mexico was over 100, I would run in 5th gear at 55 mph. Hwy. 285 from Ft. Stockton, TX to I-40 in NM is all up hill...

Buy the extra fuel, it's a lot cheaper!!!

Carl C.

10' AMC Tradition 45' with 425 Cummins

13' Jeep Wrangler

[dean0283]

Thanks Carl for the suggestion.

I think (hope) my problem has been corrected. Been driving though out AZ and NM, air temp between 90 and 100, so far engine temps are not exceeding 206 and then rapidly returning to 199.

Dean