Mountain Driving (Overheating)

[JIMNINA]

I have a 03 Yellow Stone with a CAT 3126E. We are traveling from Florida to Washington State with 4 other coaches, which are Tiffins. Going from Amarillo to Albuquerque the RV overheated 4 times. Before leaving Florida I flushed the radiator and replaced the coolant, Simple Green Extreme'd the radiator, changed thermostats when replaced coolant. Not sure what else could cause the overheating. Also, while in Florida had injectors replaced due to some bad fuel I picked up in Georgia. The coach normally runs 188-197 but we never drove anything higher than 2300' elevation. Once I got to Albuquerque I bought an 2068 CFM electric fan and installed it in hopes it will help. Any help or thoughts would be appreciated.
jim

[Restorium]

This site had some really good suggestions;

https://www.4btengines.com/causes-of-diesel-engine-overheating/

[JIMNINA]

Thanks Restorium for the information. There were quite a few things to check but I unfortunately have already checked, or replaced the items mentioned.
The electric fan seemed to work but we didn't have many steep grade uphill areas. Tomorrow is another day as we are going through Flagstaff and we are in Holbrook with an elevation rise of about 1900 feet. I am going to check with CAT and see if I can run 185 degree thermostats (Regulators in CAT lingo:))

[mhhorowi]

We used to have this same problem in the west. Ultimately we had to take the step of removing the radiator and having it deep cleaned. Once we did that, we no longer had the overheating issue. We tried everything else prior to doing this step.

[Dennis4809]

While in Holbrook, hope you toured the Petrified Forest while in Holbrook and stopped to see the Wigwam Motel. As for overheating, when pulling a long grade, forget the cruise control and shift for yourself. Drop down a gear and keep the RPM above 2,000. Computer will get it drop to 1,450 or 1,500 before downshifting. Engine is working hard and fan is slow.

If you’re heading west to CA, top of with fuel at Walmart in Ft Mojave, AZ. Couple buck cheaper than CA prices. Just came from FL to WA, arriving a couple weeks ago. Manage to go from Ft Mojave, AZ to Medford, OR on a single tank of fuel. Didn’t buy any of CA’s overpriced fuel.

Good luck,

[RayChez1]

I used to have the same problem with my 3126-E Cat engine. But what I done is to spray wash the CAC from the inside out. On mine you lift the engine cover which is where the bed is and spray wash with Simple Green the CAC and radiator, I also spray the engine let it set for about five minutes, then with an electric pressure washer, spray wash the whole thing real good. At the same time I start the engine while I am doing the spray washing and the fan will suck all that dirty and stuff that gets on the CAC and radiator and pushes it out the back. You should do this at least once every year if you travel on some dirty roads or roads with lots of debris on them. I never have had it over heat anymore. I go up high mountains like to Yosemite National park with no problems. I also have traveled through most of the mountains in the west with no problems, but before it used to over heat just going from Las Vegas to California going over mountain pass. No more!
The radiator might be clean, but if the CAC which is sandwiched right next to it on the inside is plugged up, it is your problem and should be addressed as soon as possible. Over heating is a serious problem.

[gwirth]

You need to consciously use the transmission. Keep the Rpm’ s up over 2,000. At low rpm, there is not enough air flow. When climbing steep grades, I keep my rpm’s near redline. I may go up the hill slower, but I don’t overheat. When you clean your radiator, spray it throughly with something like Simple Green and use a pressure washers to rinse it. My coach is kept under cover on concrete. When I rinse the radiator, there is a river of mud under the coach. Hope this helps.

[David Swenson]

I have a 03 Yellow Stone with a CAT 3126E. We are traveling from Florida to Washington State with 4 other coaches, which are Tiffins. Going from Amarillo to Albuquerque the RV overheated 4 times. Before leaving Florida I flushed the radiator and replaced the coolant, Simple Green Extreme'd the radiator, changed thermostats when replaced coolant. Not sure what else could cause the overheating. Also, while in Florida had injectors replaced due to some bad fuel I picked up in Georgia. The coach normally runs 188-197 but we never drove anything higher than 2300' elevation. Once I got to Albuquerque I bought an 2068 CFM electric fan and installed it in hopes it will help. Any help or thoughts would be appreciated.
jim Jim might want to try a new radiator cap first then next I would be suspicious of the new thermostat. I have gotten a bad one before even though it was new. Hope this is helpful.

Dave S

[JIMNINA]

Thanks for everyone's comments. Wanted to give everyone an update. While in Holbrook the engine A/C compressor locked up. Since it was Memorial Day weekend no services available. So on Monday we were towed to Flagstaff to Freightliner. They didn't have the compressor there but had one in Phoenix since we had nothing better to do we drove down to get it. Once we left Flagstaff we still were having some issues with the coach running hot. We hit 220 going over the Hoover dam. We did make it to Vegas and I went under and checked the belts and the water pump belt was loose. I went and bought two so we would have a spare. Went to leave and didn't even get 6 miles on flat grounds and the temp was 208. We went to the Cashman CAT dealer to get it checked out. Turned out the idler for the serpentine belt was bad. So they changed both the idler, water pump adjuster and cleaned the radiator. We then left and drove to Three Rivers next to the Sequoia National Park. Temp never went over 209 and when we drove to Yosemite over the new 120 it only hit 210 once. All seems well with the exception of a belt squeak that has developed:( I'll crawl under and check it out.

[Restorium]

The belt squeak;

If you didn't replace the belt it's probably time to replace. They squeak when they are worn.

[JIMNINA]

Forgot to mention both belts were replaced. The serpentine belt at Freightliner with the new A/C compressor. The other I replaced right before the coach went to the CAT dealer:).

[RayChez1]

I noticed that you never mentioned if the CAC was washed when they done the radiaor? The CAC is usually the problem getting plugged up with debris, not so much the radiator.

[JIMNINA]

Hey RayChez,
Thanks for the responses as I've seen that we have almost the same coach. I almost PM'd you about this instead of posting it to the forum.
I cleaned out the CAC about 6 months ago, but thought it was the radiator:) Since I was thinking backwards I never did the radiator so it hasn't been cleaned for many years. It seems everything is okay cooling wise. We went up to Yosemite and back with no overheating issues.

[RayChez1]

That is good that you did not have any heating problems going to Yosemite. I got reservations at TT Yosemite for Aug 29, 2019. I will spend about three weeks up there. We had lots of fun last year up there, so we are going to do it again this year. Our daughter will come and meet us there. She has her own travel trailer.

Was wondering which route you took up to Yosemite. I usually take 120 from Monteca, Ca.

[JIMNINA]

RayChez,
We took 108 to 120 and then the new Preece Grade (Not sure of the spelling) It has the same grade but over a much longer distance. We stayed in Groveland at Yosemite Pines RV Park. We are traveling with 4 other coaches and doing the Clark and Lewis Trail, since we are doing the trail backwards:)

[RayChez1]

I don't think I have driven highway 108 before. How was the drive and is it a good road for 40' coaches?

You come out at Oakdale? So that means you still have the twelve mile climb to Groveland? Am I correct or is 108 the two lane road that departs from 120 coming out of Yosemite just before you get to Groveland. I know many years ago I took a two lane road going down the mountain just before I got to Groveland and it come out close to Modesto, and the road was not bad, but I can not remember which road it was anymore. That is why I stay on the 120 into Manteca, but it is a lot more miles for me coming back to Barstow.

[JIMNINA]

It was a pretty decent road and it handled 40' coaches well. The four coaches we are traveling with are all 40' w/toads as well. The biggest toad is a Dodge Ram 4 dr, 4 wd HEMI.

[RayChez1]

How do you like traveling in a caravan? We used to travel with ten coaches from the club and I did not like it at all. Too many stops, either somebody in the caravan has to go to the bathroom or something else. California to New Mexico balloon fiesta was what made me not do it anymore. Also the 49ers rally at Furnace Creek. Some coaches have problems so it delays everybody. I do not want that anymore. Just wondering how you handle that.

[JIMNINA]

The 4 coaches we travel with are friends that we camp with quite often so all is good. If a coach breaks down the others in our group just leaves with best of luck. This happened twice to us and we just caught up with the group when we were able. They did stay for a few hours during the first break down to see if I was able to get on the road. The second break down two other couples broke down as well so the group was apart until the following day. Since all of us have dogs our stops are usually every 2-3 hours so everyone, including the dogs can get relief:) I think it makes it harder if you don't know the folks you are traveling with.