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Cat C-12 overheating

Yahoo Message Number: 17131
I have read a lot here about overheating issues with Cat C-13 engines. We have a 2004 Intrigure Ovation that we purchased new in Dec 2004. Last week we overheated climbing into Flagstaff on I-17 from the north. The ouside temperature was only 85 degrees. Two times the alarms went off and we were instructed by dash messages to stop driving. The Silverleaf read engine coolant warm. As soon as we stopped the engine temperature began to drop and we were able to continue. We are currently at Beaudry and nobody can figure out what's wrong. Has anybody else had this problem with a C-12?

Linda and Ben Nathan
Intrigue 11724

Re: Cat C-12 overheating

Reply #1 –
Yahoo Message Number: 17135
Linda and Ben,

How fast were you going when you over heated and in what gear? When our C-13 over heated we were going 45 mph in 4th gear and our RPMs were low, around 1400. I remembered what the Cat guy once said at a seminar, get your RPMs up so we pulled to the shoulder, let the engine idle for 5 minutes, the temp came down to 215 and we continued up the mountain in 3rd gear at 30 mph with the trucks. Also had the air off. Don't know what your problem is but going into a lower gear will help. On this particular day the outside temp was 110 at the mountain base and 99 up top. We were towing a 5000 pound Envoy. Sometimes you just need to take the hill a little slow. We were traveling with a 40 ft Mountainaire and he went up at 50 mph, but he was 12000 #s lighter then us and he had a smaller car.

Bill G. 2005 Magna #6425

Re: Cat C-12 overheating

Reply #2 –
Yahoo Message Number: 17137
Re: [Country-Coach-Owners] Cat C-12 overheating At 7:09 PM -0400 6/24/05, nathanmu@... wrote:

Re: Cat C-12 overheating

Reply #3 –
Yahoo Message Number: 17143
Bill,

We had our coach in cruise and it was making all of the decisions. When we purchased our moorhome there was a lady in here in the park with a coach jus like ours and she told us she had overheated one time when she was manually controlling the transmission so she always kept it is cruise and had no more problems. Thank you. Linda

Re: Cat C-12 overheating

Reply #4 –
Yahoo Message Number: 17144
Dick,

I am sorry that my post was unclear. We have a C-12 engine. Apparently there are no recalls for the C-12, but it sounds like a similar problem to us. We have been working with Chris Snyder for the past week. Thank you.

Linda

Intrigue 11724

Re: Cat C-12 overheating

Reply #5 –
Yahoo Message Number: 17152
I have an '04 42' Ovation with the C-12 as well. I have not had an overheating issue but I have not driven much and have not really taxed it. However, if you have not already had it done, CC has a recall on the rear engine door to change out the solid door with a grill to allow more air to exit.

Since I am about to run out of warranty I would like to hear comments from others with the C-12 in an '04 or '05 42' Ovation that feel that they have really taxed it without any problems. I would like to have warm feeling that I will not be faced with similar problems as the C-13. I contacted CC and they are not owning up to any problems with the C-12.

Jim Grossen, #11719

Re: Cat C-12 overheating

Reply #6 –
Yahoo Message Number: 17154
Linda,

We have owned 5 motorcoaches including 3 Country Coaches and have never went up a big mountain in cruise or with the mode on. We use the cruise on smaller hills but these coaches need to be driven up major mountains by a driver not the computer. The cruise will let the RPMs drop before shifting and you don't want to do that on a steep grade. We have had our C-13 refitted with all the latest overheating equipment but I would not take it over the Rockies in cruise. Let me add one more thing, I hope you know that when going down a mountain your coach will go out of 4th gear into 5th or 6th if you let the rpms get to high. Here the computer will think that you need a higher gear if rpms go to high, even with the Jake on.

Bill G. 2005 Magna #6425

Re: Cat C-12 overheating

Reply #7 –
Yahoo Message Number: 17155
Bill, I disagree about the use of cruise control. Like you, I have owned many motorhomes and have always used cruise when climbing a grade. I agree that you may not want to use the mode feature though, even in mode you can use the down arrow to control the gear and engine revolutions. This has worked for me with light coaches like Safaris, heavy coaches like Wanderlodges and in between like my current CC. I guess there is more than one way to skin a cat....or climb a grade.

George in Alabama
'04 Allure 31038
George in Birmingham
2003 Magna 6298

Re: Cat C-12 overheating

Reply #8 –
Yahoo Message Number: 17157
We have had overheating problems as well.
CC told us to disconnect the wire to the fan so it will stay on when we are in hills.
It does help but what else can we do? 2004 Intrigue.
11825

Re: Cat C-12 overheating

Reply #9 –
Yahoo Message Number: 17158
I agree 100% with Bill G. Driving the coach up and down hills is far better then trying to let the cruise control do everything. I find this to be equally true in a car.
When you "drive" the coach you can anticipate changes in grade up and down and either speed up or slow down accordingly. An extra five mph just before a steep grade gives the coach a real advantage when it reaches the steeper part.
AND, IMHO the driver has much more control over the vehicle. That said, I do use cruise extensively on long flat runs and believe that helps my mileage during those part of the trips.
But of course I am only an amateur big rig driver. What do our professional truck drivers do?

David

David & Karen

2000 Intrigue 11062
40 ft Single slide. PT
2002 Odyssey TOAD

Re: Cat C-12 overheating

Reply #10 –
Yahoo Message Number: 17159
When we were at the CC reunion several of the Intrigue models were equipped with the new CAT engines in place of the Cummins ISL. If I remember correctly option charge was about $40K, a heavy price to pay but at least it came with the extra power.

 At the same time there was an increase of about $4K on units fitted with the Cummins ISL, supposedly because of some EPA penalty for emissions.

 At the same show a Guaranty employee told me that they (Guaranty) were specifying Cummins on purchase of coaches for their showroom stock. Maybe they just wanted to keep the MSRP lower or maybe they were waiting for the bugs to be sorted out on the new CAT engines. Either way, buyers of the Cummins 400 ISL appear to have avoided the recent problems on the CAT.

 David

Re: Cat C-12 overheating

Reply #11 –
Yahoo Message Number: 17168
Bill,

You drive your coach the way you want to, but there is absolutely no reason not to let the computer drive up the hills. It won't anticipate hills, so you can manually increase speed before the first uphill, but this only makes a difference for a very short time. The economy mode does just fine also, but since it shifts down later, it won't keep the coach at peak HP, which is peak hill-climbing ability. If I want to keep speed up, I shift out of economy mode on hills. Once you are at a certain speed and in a particular gear, it makes no difference whether a computer or a person is controlling the engine.

Per

95 Affinity

gablerwh@... wrote:

Re: Cat C-12 overheating

Reply #12 –
Yahoo Message Number: 17172
Jim ...

I also have an 04 42' Ovation with a C-12. So far overheating has not been a problem with me either. I recently ran I-79 North from the Carolinas, up the 7 mile grade into Va. Most of the trucks were pushing about 30 or so, I never dropped below 50 and was fully loaded and towing a 5200# Tahoe. The silverleaf was registering 1542 ft/lbs of torque. I must admit, I was pretty amazed, but that C-12 seems to have power to spare.
I did not know that the Ovation ever came with a solid door on the rear. Mine has some pretty large louvers If you are worried about your warrantee expiring ... might be a good time to check on an extended plan. With a $400,000.00+ coach, what's another 4 or 5 grand, for some peace of mind.

Jay & Stephanie

04 Intrigue Ovation #11821

Quote from: Jim Grossen
I have an '04 42' Ovation with the C-12 as well. I have not had

an

Quote
overheating issue but I have not driven much and have not really > taxed it. However, if you have not already had it done, CC has a > recall on the rear engine door to change out the solid door with a > grill to allow more air to exit.

Since I am about to run out of warranty I would like to hear > comments from others with the C-12 in an '04 or '05 42' Ovation

that

Quote
feel that they have really taxed it without any problems. I would > like to have warm feeling that I will not be faced with similar > problems as the C-13. I contacted CC and they are not owning up

to

Quote
any problems with the C-12.

Jim Grossen, #11719

Quote from: nathanmu@a...
> I have read a lot here about overheating issues with Cat C-13 > engines. We

> have a 2004 Intrigure Ovation that we purchased new in Dec > 2004. Last week

> we overheated climbing into Flagstaff on I-17 from the north.

The

Quote
ouside

> temperature was only 85 degrees. Two times the alarms went off > and we were

> instructed by dash messages to stop driving. The Silverleaf

read

Quote
engine coolant

> warm. As soon as we stopped the engine temperature began to

drop

Re: Cat C-12 overheating

Reply #13 –
Yahoo Message Number: 17181
David,

Some MH companies are taking the Cummins 400 ISL engine, reducing the torque and using a 3000 trans. Thats one way to reduce the cost, avoid the overheating and still advertise a 400 ISL engine.

Bill G. 2005 Magna #6425

Re: Cat C-12 overheating

Reply #14 –
Yahoo Message Number: 17185
Bill, I don't understand your post. The ISL400 engine is always configured with the Allison MH3000. That transmission has a max torque

of 1,200 lb ft and a max GVW of somewhere around 50K lbs.

On the subject of reducing torque perhaps you are thinking of the ISL350 which has a mx torque of 1050 lb ft.

George in Alabama
'04 Allure 31038
George in Birmingham
2003 Magna 6298

Re: Cat C-12 overheating

Reply #15 –
Yahoo Message Number: 17212
George,

I was told by one of the manufacturers that the 400 Cummins has a torque of 1250 and they put a chip in the engine to take it down a little to make it work with the 3000 trans. That could be wrong but I believe the last time I look at the 400 spec it said a max torque 1250 and when I asked a coach rep how they use that engine with the 3000 trans thats what he said and they do it to save money. If you recall on the 01 Magna CC put a 385hp Cat C10 but they used a 4000 trens.

Bill G.

Re: Cat C-12 overheating

Reply #16 –
Yahoo Message Number: 17229
Bill, you're right that the Cat 385 C10 uses the MH4000 transmission.
That is because of it's torque rating at, I think, 1,350 lb ft. In any event it is above the 1200 limit of the MH3000.
My look at the Cummins site shows no over-the-road ISL with more than 1,200 lb ft of torque. I think that your source was in error.
In any event, I don't think you will find an ISL application anywhere in the industry that uses the MH4000. More importantly, I love my ISL400 and Allison MH3000 and would recommend it to anyone with a coach they will run below 40,000 lbs.

George in Birmingham
'04 Allure 31038
George in Birmingham
2003 Magna 6298