Overheating 2004 Tiffin allegro bus 36 OP cat. 3126 e 330 hp

[Bernie_G]

Hello everyone.
I am new to this forum (actually any and all forums) I have just joined this forum this morning. I would appreciate any help I can get as I am at my witts end. I have a 2004, 36 OP allegro bus with a 330 hp, 3126 E cat. pusher with a side air inlet and hydraulic fan motor. The problem is that it is constantly overheating. I have spoken with Bob Tiffin 3 times while trying to get this problem resolved. I have been to Frieghtliner in Whiiter CA, La Mesa RV in San Bernardino, a local Tiffin repair facility "M&M Coach" that Mr. Tiffin sent me to in Ontario CA, and Johnson Power the Cat. dealer/representitive in San Bernardino CA.
It has had a new radiator installed, new surge tank and cap, new thermostates 2 of them as it takes 2 thermostats, all new belts and hoses, new fan blade etc.. It spent 4 days on the dyno at the cat facility (Johnsons Power) where they ran every test they could trying to find the problem while checking for proper operation of all of the engine cooling and operating systems including the ECU. They said they put 4 different programs into the engines control module/computer (evidently it had the wrong program in it?) before they were able to attain the best operating program for this coach.
Also, the gentleman that Mr. Tiffin sent me to at M&M Coach was the owner of M&M Coach must be recognized for his outstanding service that he gave me. He wanted to help me find the problem with this coach so he went for a ride with me so he could observe my driving habits/skills while towing my Jeep up and over Cajon pass in Ca. He also drove my coach up and down Cajon pass. The coach heated up at virtually the same place each and every time, it did not matter who was driving it. I have all the reciepts to show that I have paid for all of the repair work that I have had to do on this coach, with the exception of what M&M Coach did for Tiffin Motorhomes through their representative at M&M Coach in Ontario CA.. They did install an overheating kit they had, which included a fan shroud and parts that closed in this area of the coach to help the fan pull air through the radiator, as well as installing metal louvers in the engine compartment doors and cutting holes and installing expaned metal in the openings they cut in the back of the coach.

Bottom Line; Frieghtliner blames the coach builder, Cat. blames this guy and Tiffin says they have done as much as they can and basically every body just wants to point fingers. Just to be clear I am not trying to do anything more than get this coachs overheating prolems fixed as my wife really liked this coach. I purchased this coach in 2007 from a gentleman that was the second owner with between 12,000 to 15,000 miles on it so I guess you can say buyer beware. I am the third owner of this coach.
Can some one please help me with this, as I would really like to use the coach this year to go back into Colorado for my sisters 50th wedding anniversary. Again it is a 2004 36 OP allegro bus with a drivers side air inlet with side mounted radiators, hydraulic fan motor, 330 hp 3126 E Cat. motor. Thank you for your help and advice. Bernie G.

[gatorcq]

1 temperature sending unit on the CAT. Signal comes from ECU to gauge.

Cannot be backward turning fan, it would be OH all the time

[PaulJ2]

It seems pretty basic to me here. Monitor the water temp going into the radiator. Then monitor the water temp coming out of the radiator returnimg to the block. Is there the proper temperature drop? Not ok means an air flow problem (should hear the fan roaring on high speed)? If this all ok then engine is retaining too much heat inside the block.
Next I would pull the water pump, maybe vanes set for one operating the wrong direction? Dumber things have happened. Thats where I would go.
Would be interesting to know the previus owners histories.

[wolfe10]

Thanks for the update.

Glad it was something relatively simple and inexpensive.

[Dogpa]

I picked up my coach today at the local CAT dealer. When they put in shop they tested for codes found that yes it had been overheating and all hoses, thermostats, fan rotation, speed and direction were correct. When they inspected the side radiator system they found it completely clogged up. You can't see this condition from road side. They put a special solution on it then steamed it and then used a special pressure washer, so as to not damage fins, and blew it out. They test drove for 50 miles on grades and it ran at 200 (normal for a C7 350 HP) and outside air was well over 100. Picked it up today and ran it to storage and it ran at or below 200. They said at least once a year this needs to be addressed on side draft radiators. Power wise they advised the C7 was at peak power and that re-ehausting or chipping it would not be of benefit for more power, just FYI. Now if I could just get the dash air to work good...

[Dogpa]

Interesting, I have a 2005 Mandalay 40B with a CAT C7, 350 HP, side radiator as well. I have 34,000 miles and am second owner of coach, since 20,000 miles. My engine overheats just as yours does and even when not towing. I live in Vegas and it heats up in the same pass as yours, I try to run at 2000 rpm to stay cool. I have just returned from a trip to Austin and had overheating problems the entire way. I have it at the CAT dealer now being inspected and have heard of all the remedies that are listed, clean radiator, hoses, belts, etc with no success. Will post results when Coach is returned from CAT.

[stuplich]

gswcgi wrote:
I have the same engine with a rear radiator in a 2003 Safari. Never have had a over heating issue in 41,000 miles. Here are some thoughts:
If you have a lot of gunk in the radiator this will help.

The OP said it is a "new radiator"!

[Dale_Traveling]

Bernie, when the rig was on the dyno what did they use to determine engine temperature? You didn't mentioned that it was overheating on the dyno. I wondering if you have a faulty dash gauge. You haven't mentioned that the engine dropping into limp or shutting down which I would expect if the ECU detected a coolant high temp.

Also there might be two temperature sending units on the engine. One for the ECU and one for the dash gauges. The dyno techs may have been only checking what is reported to the ECU and not comparing the dash gauge.

It's a bit of a WAG (Wild A@# Guess) but at this point who knows.

[BobGed]

wolfe10 wrote:
While the RADIATOR may be clean/net, it is the CAC that that "filters" the dirt out of the air and reduces air flow through the whole cooling system. So, it is a relevant point.

With all the tests that the OP states were performed, don't you think all of the obvious possible contributors to his problem were addressed?

[Wheel_Estate]

x'2 on Gaffney SC....they seem to to the best in many cases

[wolfe10]

BobGed wrote:
A couple of folks have suggested a radiator cleaning. I think if you go back to the OP's original post you'll see that he has had a new radiator installed.

While the RADIATOR may be clean/new, it is the CAC that that "filters" the dirt out of the air and reduces air flow through the whole cooling system. So, it is a relevant point.

[BobGed]

A couple of folks have suggested a radiator cleaning. I think if you go back to the OP's original post you'll see that he has had a new radiator installed.

[Louandsal]

I had an intermittent overheating problem. Didn't lose any coolant, the gauges and warning buzzer went wild. Freightliner in Springfield, Mo, couldn't find the problem, hoped that downloading updates would cure the problem. Updates didn't help at all. Problem got increasingly more frequent. Freightliner Service Center in Gaffney found the problem, the fan clutch was slowly, very slowly leaking oil. As it leaked more, it overheated more often. Got that replaced and it ran like new, until the turbo went out 2 days later!!!

[gswcgi]

I have the same engine with a rear radiator in a 2003 Safari. Never have had a over heating issue in 41,000 miles. Here are some thoughts:

With the radiator warm, spray some Simple Green into the radiator and let it sit for 15+ minutes then spray it down. If you have a lot of gunk in the radiator this will help. Do not use high pressure water as you can damage the radiator veins. The other thought i have is that in most coaches with a Cat engine and an Allison transmission they are tied together with a common cooling system. Does your transmission also get hot when your engine over heats? If your transmission also gets hot you may have an issue with the transmission and not the engine.

[I_rv]

i would go to cat dealer,a few years ago i had engine breakdown outside L.A. I was towed to cat dealer in"city of industry" can't remember dealer name however my experiance was they were very knowlegeable polite making a bad experiance not that bad. good luck