C7 Slow Start

[firedoc]

Originally Posted by Tizbad

Well stated CountryB. I agree that it may be a sensor or something simple. I did suggest in post #7 that a Cat dealer should look for codes and sensor issues, and while there update the Flashfile.
Regarding software, I do not recall any C7 in this time frame that had cold operating issues as severely as described. Since I was involved in the launch of this engine, I do know that early C7's did not perform as well as the former 3126's. I reprogrammed many motorhomes myself for this problem.

Could you expand on why early C7 s did not perform as well as the replaced 3126 and what you did?

[Mr_D]

Originally Posted by CountryB

I hope they did not charge you for the pump. If so, they owe you a refund.

I haven't had a CAT since 2002 but even so I agree. I really dislike "parts changer till we solve the problem".

[FIRE UP]

Originally Posted by firedoc

Could you expand on why early C7 s did not perform as well as the replaced 3126 and what you did?

Yeah,
I too am wondering about the statement that the early versions of the C-7 did or does not perform as the 3126. The chassis production date of my coach, is 10/03. The Coach part was 11/03. The date first put in service was 1/04. According to any digging around and info I've found, I have fairly close to one of the first C-7s in a Freightliner chassis coach. There are folks I've chatted with on here and other RV forums that have Winnes and Itascas, produced in the same month, with 3126s where as, as state, mine has the C-7.

And, our C-7 will run right alongside, and in many cases, IN FRONT of any 3126 I've ran up against. We've talked on radios and those boys knew and know how to drive their rigs and could not overtake me, based on given loads, roads, grades, tire sizes and pressures and more. Now, the 350HP version (of the C-7) is only slightly more powerful than my 330. I've got one buddy that has the 350 in his 36' Meridian and, on Mountain Springs Grade, in the eastern part of San Diego County, we'd be equal at the bottom. But, at the top, he'd be right at two coach lengths ahead of me. Again, based on load and all else being equal. Not a big difference in my book.
Scott

[firedoc]

Originally Posted by FIRE UP

Yeah,

I too am wondering about the statement that the early versions of the C-7 did or does not perform as the 3126. The chassis production date of my coach, is 10/03. The Coach part was 11/03. The date first put in service was 1/04. According to any digging around and info I've found, I have fairly close to one of the first C-7s in a Freightliner chassis coach. There are folks I've chatted with on here and other RV forums that have Winnes and Itascas, produced in the same month, with 3126s where as, as state, mine has the C-7.



And, our C-7 will run right alongside, and in many cases, IN FRONT of any 3126 I've ran up against. We've talked on radios and those boys knew and know how to drive their rigs and could not overtake me, based on given loads, roads, grades, tire sizes and pressures and more. Now, the 350HP version (of the C-7) is only slightly more powerful than my 330. I've got one buddy that has the 350 in his 36' Meridian and, on Mountain Springs Grade, in the eastern part of San Diego County, we'd be equal at the bottom. But, at the top, he'd be right at two coach lengths ahead of me. Again, based on load and all else being equal. Not a big difference in my book.

Scott

While waiting for an answer to my other question, I will present another:

I have a 300hp C7. People have said that the only difference between my 300 and the 330 and 350 was a software programming. This would be nice as I could have mine flashed But I would think the must be other hardware differences also! Do they have beefier rods, different bearings or cranks? Is there a difference in injectors, etc. I believe all three were mounted to an Allison 3000 so transmissions shouldn’t matter. What’s up?

[CountryB]

Originally Posted by firedoc

While waiting for an answer to my other question, I will present another:

I have a 300hp C7. People have said that the only difference between my 300 and the 330 and 350 was a software programming. This would be nice as I could have mine flashed But I would think the must be other hardware differences also! Do they have beefier rods, different bearings or cranks? Is there a difference in injectors, etc. I believe all three were mounted to an Allison 3000 so transmissions shouldn’t matter. What’s up?

Same engine internals - just programming.

[Tizbad]

Originally Posted by firedoc

Could you expand on why early C7 s did not perform as well as the replaced 3126 and what you did?

At the initial launch of the C7, there were performance complaints from a dead stop. At the factory, we tested 3126's against C7's and verified that there was a difference between the two engines, and there should not have been. Without getting into specifics, there are some "iron differences", and there were emissions requirements that changed, which meant that the C7 had different software compared to the 3126. Revisions were made to the initial software release and C7 performance met or exceeded the 3126 after this change. Early on, many coaches prior to the engine serial number I provided were "reflashed" (re programmed) to correct that problem.

[Tizbad]

Originally Posted by firedoc

While waiting for an answer to my other question, I will present another:

I have a 300hp C7. People have said that the only difference between my 300 and the 330 and 350 was a software programming. This would be nice as I could have mine flashed But I would think the must be other hardware differences also! Do they have beefier rods, different bearings or cranks? Is there a difference in injectors, etc. I believe all three were mounted to an Allison 3000 so transmissions shouldn’t matter. What’s up?

Software only to make this change. Just remember that more fuel means more BTU's, so you need to watch the temp. gauge a little closer.

This table verifies your question:
http://ww2.justanswer.com/uploads/bu..._Nov06_Rel.pdf

[COdutchstar]

Thanks CountryB, I have a ScanGuage and I will play with it this weekend. I have not had it very long and am still learning how everything works.

[Mike and Pat]

I have a 2004 Meridian with C7 and I have had the same problem for years. I replaced Throttle Control Sensor with no luck. My Huie was replaced due to failure and that did not change anything either. Once Temp is up to 160 it does fine before that no power. I have a scan gage and it is not showing any codes. It has been to at least 6 shops for different things in the last 8 years and no one can find a problem.

[FIRE UP]

Originally Posted by firedoc

While waiting for an answer to my other question, I will present another:

I have a 300hp C7. People have said that the only difference between my 300 and the 330 and 350 was a software programming. This would be nice as I could have mine flashed But I would think the must be other hardware differences also! Do they have beefier rods, different bearings or cranks? Is there a difference in injectors, etc. I believe all three were mounted to an Allison 3000 so transmissions shouldn’t matter. What’s up?

firedoc,
I was also lead to believe that it was only programming that made the differences in the three versions of the C-7. Well, while in Sparks NV, getting my valves adjusted at Cashman CAT, I was watching and talking to the tech, doing the valve adjustment. This tech had/has tons of experience with CATS. The subject of kicking my 330HP up to the 350HP version was brought up.

Up to this point, I'd always thought of flashing mine to the 350HP version. But, the CAT tech, told me that the software to do it is proprietary to CAT and it's NOT CHEAP. Consequently, he told me that, yep, "We could do it right now but, good thing you're sitting down, the cost of that flash is right at $500 or more"!!!!!!!!!!!

He then stated; "Are you sure you want to pay upwards of $500-$550 for a 20HP gain"? I thought about it for oh, maybe a NANO SECOND, and replied "Naw, I think I'll keep her the way she is, thanks anyway". He said, "Yep, that's the same exact reply I've seen many, many times". As I said earlier, the prime benny for the 350 vs the 330 is, higher end engine speed is where the added 20HP helps. Climbing grades, with two identical rigs, identical weights, one with the 330 and one with the 350, the one with the 350 might, I say MIGHT finish at the top of the grade, maybe a coach length or two, ahead of the 330, all things being equal.

$500+ is just not worth it for me to be 2 coach lengths ahead of myself. Don't get me wrong here. If I had the 350HP version, I'd be happy. But, to pay that kind of money to get it, and the barely visible/felt results, nope, ain't happening.
Scott

[GBDTN]

Not much to comment,after three years and several mechanics across the country and including Freightliner Gafney, but my 350 will limp out at below 145 degrees and 140 above 5000’. Only answer I get is its a cat and pump and engine need to be warmed up at high idle before taking off. I try to idle off to a spot away from everyone to do this. In the camp spot and reg idle for upping jacks and slides it wont warm up to that at 50 to 60* out air. Yes i cleaned the radiator

[GBDTN]

Sorry my keyboard crapped out, we have checked it on the computer twice and can find nothing wrong and flash is up to date. Oil. Once a year and filters. Running a scan gauge. 28# boost and i am afraid to take off now till it warms up unless it is a down hill or level no power demand type of takeoff.
Fireup, staying down at Parker, any suggestions on alignment shop in the area? Gafney replaced a bearing and airbag and its pulling some on good roads. Usually the roads or wind is so bad it doesn’t matter, but on some good roads is annoying.
PS. I wash the radiator after every trip. If not the oil the dirt. Dust is awful out west and once its clean its easy to keep clean.

[FIRE UP]

Originally Posted by GBDTN

Sorry my keyboard crapped out, we have checked it on the computer twice and can find nothing wrong and flash is up to date. Oil. Once a year and filters. Running a scan gauge. 28# boost and i am afraid to take off now till it warms up unless it is a down hill or level no power demand type of takeoff.
Fireup, staying down at Parker, any suggestions on alignment shop in the area? Gafney replaced a bearing and airbag and its pulling some on good roads. Usually the roads or wind is so bad it doesn’t matter, but on some good roads is annoying.
PS. I wash the radiator after every trip. If not the oil the dirt. Dust is awful out west and once its clean its easy to keep clean.

Hey GBDTN,
Really sorry for your issue. That would drive me right up the wall if mine wouldn't take off 'till it had some heat in the engine. OBVIOUSLY something's not right since, until reading this particular thread, I've not heard of this issue with any version of a CAT engine. And I've got at least a good dozen of friends with CATs in their coaches.

I'm not quite sure what I'd do in this situation, sell it or, put out a nation wide APB for ANY CAT TECH that could yank that engine out of it's dilema. May drive it (after it get's warmed up) to the CAT factory and park it in front of the front door and leave it there 'till one of the engine designers figures it out. Just kidding.

Now, as far as a recommendation for alignment here in Lake Havasu City, Well, I've not had them do it yet but, I've got friends here who have used them and praise their work. I'm speaking of Three Ts RV here. They supposedly have some form of Computer alignment that handles RVs. I spoke to them about mine but, never made an appointment. They did do my slide block work. If you're not sure or need directions, it's simple. Take 95 from Parker, all the way into Lake Havasu City and, at Kiowa and 95, hang a left on Kiowa. Go about 1/4 mile to Empire. Hang a right on Empire.

At about 100 yards, the entrance to their facility is on the left. Many on here have dealt with Three Ts for various repairs. They've been directly involved with Winnebago for years. Paul was the owner and main guy for a long time. now, one of his daughters is the head honcho. She's "Tina". Obviously, one of the "Ts". Good luck.
Scott

[gatorcq]

By the way, back to my earlier post.
Based on his description, the ECU (electronic control unit) may be seeing the Cold Mode Fault. This is really not a fault, but can be caused by an erratic air inlet sensor.
It is based on a calculation of Coolant and Air inlet temperature.