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fuel milage and smoking

Yahoo Message Number: 82188
Over the past few months there have been questions about excessive smoke coming out the tail pipe.

Also questions about fuel economy and my curiosity about if the new ultra low sulfur diesel fuel could

be the issue. Well in my case both issues were solved with a new charge air cooler. my fuel milage went

back up and the smoking which only shown at high altitudes while the turbo revved up, has now

become a quick brief poof. I drove from Eugene via I 5 to the Bay Area in California and averaged 9,2

mpg and 8,8 from the Bay Area over Donner Pass to Reno and on word to Ely, Nevada on Hwy 50 with its

10 mountain passes. The only smoke I saw was a poof here and there when over 7,000 ft. My milage

has gone up any where from .7 to 1 mpg. My coach shift patterns have changed to. Where before I

instantly shifted from 6th to fifth going up a grade now it stays in 6th .
Shifting to 4th only happens

when on 6 + % grades and my speed has increased any where from 5 to 7 mph at 6 and 7% grades. Any

thing steeper and 43 mph is it, sometimes 36 in 3 rd. So if you guys are frustrated and have a JB

charge air cooler, get it checked! I bet its leaking. TWI 2004 42' Intrigue 11731 with ISL400. 44,000lbs with coach and car

Original Message:
-----------------

From: Rod jrodneyrobbins@... Date: Fri, 07 Sep 2012 03:48:23 -0000 To: Country-Coach-Owners@yahoogroups.com Subject: [Country-Coach-Owners] Re: Shocks

Hi Dave

The deciding factor for me was the quality of the shock. Once i got my hands on one i admired the way

they were built. I also got recomendations on the forums.I had porposing and bottoming out with the

factory setup.I first did the front then replaced the rears. Roadkings were my choice.
Rod
inspire
51473

Quote from: Dave Hansen \[br\
]
I'm looking at getting new shocks for our coach.
I asking this group, if U replaced your shocks on your coach > what was the deciding factor for U to go with the shock that you > put on the coach.
Price..

word of mouth

your endless search on the web
> I do not want to get into a big discussion on who has the best shock > just why did you go with what you did.
Thanks

Dave

07 Country Coach Allure 430 #31495 > 12 Jeep GC Toad
Mountains of So Cal
mail2web.com - Microsoft® Exchange solutions from a leading provider - http://link.mail2web.com/Business/Exchange

Re: fuel milage and smoking

Reply #1 –
Yahoo Message Number: 82190
One thing that you may also consider is to install a boost pressure gage. On my 8.3 mechanical Cummins I see a maximum of 22 psig with about 10 on a flat road at 60 mph. As long as your pressure is up, small leaks will not hurt performance.
RUSSELL WARREN '95 INTRIGUE 10070

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Re: fuel milage and smoking

Reply #2 –
Yahoo Message Number: 82191
I would be interested if your mileage was computed by your Silverleaf or by the actual miles divided by the amount of fuel used on a calculator?

Thanks,

Jock Vargo
2025 Inspire
51428

Re: fuel milage and smoking

Reply #3 –
Yahoo Message Number: 82200
You mentioned you had your CAC replaced.

How does one go about checking the CAC or having it checked?
We are on our way back to the east coast after spending three months in the Rockies and the amount of black smoke I was putting out while above 5000 feet was REAL bad. It has always been excessive on our west coast trips.
I have always produced some smoke no matter where we were, even at sea level where we live, but this time was the worst. I purchased an new white Subaru before this trip and it would get covered with black soot from my exhaust. Also all over the back of the coach and heavy black soot stains on the fiberglass at the exhaust area.
I took it into our local Cummins shop back in March and asked them to look into the smoke. Everything checked out and they did do the 150k valve and Jake Brake adjustment which was past due.
I still have plenty of power to pull any grade although I would not want to be on a motorcycle behind me with all that black smoke. And my mileage is consistent with what I have always seen.
I see trucks blowing black smoke all the time and figured this is just normal for these diesel engines under load. But from past posts on this subject it sounds like black smoke is not all that normal.
Any thoughts would be appreciated. Seems this issue with soot on the back of the coach only started getting bad in the last few years.

Richard Aquino

2001 Intrigue ISL370.

Re: fuel milage and smoking

Reply #4 –
Yahoo Message Number: 82202
I have the same motor as you only its chipped for 400 HP and I never had a smoke problem. My intercooler was changed 2 years ago when it flunked the test where they submerge the unit in a water bath. This was done only because I was having the radiator replaced. The leakage was quite minor, however it would have been foolish not to have replaced it as long as it was already removed. Prior to this it was not smoking nor did I have any significant power loss. I must disagree with your statement on seeing trucks blowing smoke all the time. Sure on old logging trucks that shoudn't be on the road or ocaasionally I see puffs when going through the gears but in general they are quite clean. A telltale sign is the side of the trailer the tractor is pulling. You defintely have a problem

Ed McManus......'02 Intrigue.......11361

Re: fuel milage and smoking

Reply #5 –
Yahoo Message Number: 82203
Richard, Hi, I had my CAC replaced last year due to excessive "black smoke" and noticable loss of power.

1. After CAC fix black smoke at sea level up to about 3,500 -4,000ft little or no smoke. At 5,000 feet above we get black smoke on acceration or when slowing down and then reaccelerate. Going down the road I don't see smoke at elevation.

2. I call the Cummins Corporate "HOT LINE" for explanation. They stated the ISL with a CAPS "Cummins Accumulator Pump System" high pressure fuel pump will produce black smoke at altitude, even though the engine has a barometric sensor.

3. However the Cummins Engineer explained that with the CAPS system the coach doesn't loose Boost Pressure; however, he explained that with the later upgrade to the "Common Rail" fuel system, you'll have less black smoke but will loose a little "Boost Pressure" at altitude.

4. He then went on to say from 2007 and newer all their engines produce hardly any black smoke even at altitude.

5. Your Cummins shop know how to test the CAC it requres romoving the piping from the Turbo installing a Pressure Gauge then pressurizing the CAC and measuring how much pressure its loosing watching the guage over a stating amount of seconds.

6. If its a bad leak you can hear the leak and almost determine where the leak is located.

7. Also check your Exhaust Maniford for black soot marks, both the ISC and ISL are bad for cracked Exhaust Manifolds, also tighten all Air piping from Air Cleaner all the way through the system.

8. Are you using a good Diesel Fuel Additive?

Thanks, Mike 03 Allure 1st Ave. #30898 ISL 370 Chipped to 400HP

Re: fuel milage and smoking

Reply #6 –
Yahoo Message Number: 82205
Ed and Mike, thanks for the reply.
I asked the question about the CAC because the OP mentioned the replacement solved his problem. Sounds like my local shop should have no problem testing it. Wish they had tested it when in the shop early this year.
Just about every time we leave for a trip I have to climb I26 or I40 to Asheville or I77 to Fancy Gap. This is my test to see if I am running ok with plenty of power and no overheating. I don't think my fuel mileage or power is off but that is hard to tell. I don't keep track of actual fuel mileage, too many variables, and I usually climb the big hills in third or fourth gear. About a 100k miles ago I did have the radiator replaced and they pulled that system apart. Could be something has come loose but I do not hear anything unusual.
After some posts back in May about excess smoke I did tighten all the connections I could get to from inside and outside the coach.
I did have the cracked manifold replaced about four years ago and it looks ok today.
I have started, just on this trip, using a good diesel additive but only a gallon thus far and I have seen no change in the exhaust. I will continue to use an additive until I am convinced that it is or is not doing any good. This beast runs great, knock on wood, but I do want to solve the exhaust issue.
I have considered having the engine upgraded to 400HP but I am just soooo satisfied with the power I have that I hesitate to make any changes.
I am open to any other suggestions but the CAC or something back there does sound suspect at this time. I have seen a couple of other CC's in the higher elevations smoking but not to the extent of mine.

Richard Aquino

2001 Intrigue ISL370

Re: fuel milage and smoking

Reply #7 –
Yahoo Message Number: 82206
I don't have a built in Silver leaf, but have the module so I can use my lap top to monitor the engine and

transmission temps, pressures etc. I calculate the milage the old fashion way with pen and paper. I

rechecked my last three fill ups after installing the new CAC, subtracting .5 gal per hour of gen use.

The results were from Eugene to Portland, Astoria and back to Eugene. 8.4 mpg. From Eugene to Santa

Rosa Ca. via I-5 at 58 mph. 9.1. instead of 9.2. And I screwed up subtracting the gen hours so the

Milage from Santa Rosa to Reno to Ely was 7.9 over the 10 Mtn passes in Nevada on hwy 50 and

Donner pass in Ca. rather than 8.2 running 63 to 65 where I could. My error.. The last time I traveled this way in 03 when the coach was new I average 7.6 according to my records. I now have 81,000 plus

miles on the coach. I saw no sign of smoke with my eyes today but there was a very light film of soot

behind the tale pipe, which is better than the visible soot I had before at higher Altitudes. I am now in

Delta Utah, tomorrow, Moab and monday Durango.
My CAC was so bad that You could hear the leak which was on the exit tank during the pressure test.
TWI 2004 intrigue 11731
Original Message:
-----------------

From: mrgrandbanksed mrgrandbanksed@... Date: Sat, 08 Sep 2012 17:57:58 -0000 To: Country-Coach-Owners@yahoogroups.com Subject: [Country-Coach-Owners] Re: fuel milage and smoking

I have the same motor as you only its chipped for 400 HP and I never had a smoke problem. My

intercooler was changed 2 years ago when it flunked the test where they submerge the unit in a water

bath. This was done only because I was having the radiator replaced. The leakage was quite minor,

however it would have been foolish not to have replaced it as long as it was already removed. Prior to

this it was not smoking nor did I have any significant power loss. I must disagree with your statement

on seeing trucks blowing smoke all the time. Sure on old logging trucks that shoudn't be on the road or

ocaasionally I see puffs when going through the gears but in general they are quite clean. A telltale sign

is the side of the trailer the tractor is pulling. You defintely have a problem

Ed McManus......'02 Intrigue.......11361

Quote from: rlaquino2728
>

You mentioned you had your CAC replaced.

How does one go about checking the CAC or having it checked? > > We are on our way back to the east coast after spending three months in
the Rockies and the amount

of black smoke I was putting out while above 5000 feet was REAL bad. It has always been excessive on
our west coast trips.

Quote
>

I have always produced some smoke no matter where we were, even at sea
level where we live, but

this time was the worst. I purchased an new white Subaru before this trip and it would get covered with

black soot from my exhaust. Also all over the back of the coach and heavy black soot stains on the

fiberglass at the exhaust area.

Quote
>

I took it into our local Cummins shop back in March and asked them to
look into the smoke.

Everything checked out and they did do the 150k valve and Jake Brake adjustment which was past due.

Quote
>

I still have plenty of power to pull any grade although I would not want
to be on a motorcycle behind

me with all that black smoke. And my mileage is consistent with what I have always seen.

Quote
>

I see trucks blowing black smoke all the time and figured this is just
normal for these diesel engines

under load. But from past posts on this subject it sounds like black smoke is not all that normal.

Quote
>

Any thoughts would be appreciated. Seems this issue with soot on the back
of the coach only started

getting bad in the last few years.

Quote
>

Richard Aquino

2001 Intrigue ISL370.
> -

Re: fuel milage and smoking

Reply #8 –
Yahoo Message Number: 82207
The first thing to do is look at your boost gauge under a hard pull. If it reaches the max for your engine it is good if not then soap it up and look for leaks.

Mikee

Re: fuel milage and smoking

Reply #9 –
Yahoo Message Number: 82212
Mikee,

I have the Silverleaf but it is programmed for the 350ISC. No option to set it for 370ISL. Years ago one of their Techs indicated turbo boost would be one of the displays that would not be correct thus I get incorrect data when I look at that display. Silverleaf has offered to load a newer program but I never pulled it out and sent it in.
If the boost is not where it should be what do you soap? Is it all the piping connections looking for a leak? Would such a leak show up at engine idle?
I don't know if I would do it myself but I like to know what the Techs should be doing to find this type of problem. One suggestion is have them pressure test the CAC but that is only one part of the system.

Thanks

Richard
 

Re: fuel milage and smoking

Reply #10 –
Yahoo Message Number: 82214
When Cummins in El Paso and Amarillp checked my previous ISC 330 and my Current ISL they included

all the piping and boots between the turbo and the intake manifold and the issue was the CAC in al

three cases and a bad pressure fitting on the crossover pipe on the ISC.
OMC just checked the CAC as

it was already on the ground while repairing the cooling radiator under warranty. After the package was

repaired and reinstalled OMC checked the system as did Cummins. They also checked the radiator and

hoses at 15 lbs . T hen drove the coach and rechecked the systems. Dave checked my Hydraulic

reservoir to make sure the filters were covered properly, as some of the dip sticks were marked

improperly. Mine had been remarked correctly. You almost have to be your own tech to understand

what's going on and if are being treated properly or not. TWI 2004 Intrigue. 11731. ( I still think the Cummins shop in Coburg Oregon is the best for RV owners. Like their new facilities. )

Original Message:
-----------------

From: rlaquino2728 rlaquino2728@... Date: Sun, 09 Sep 2012 01:57:13 -0000 To: Country-Coach-Owners@yahoogroups.com Subject: [Country-Coach-Owners] Re: fuel milage and smoking

Mikee,

I have the Silverleaf but it is programmed for the 350ISC. No option to set it for 370ISL. Years ago one

of their Techs indicated turbo boost would be one of the displays that would not be correct thus I get

incorrect data when I look at that display. Silverleaf has offered to load a newer program but I never
pulled it out and sent it in.

If the boost is not where it should be what do you soap? Is it all the piping connections looking for a

leak? Would such a leak show up at engine idle?
I don't know if I would do it myself but I like to know what the Techs should be doing to find this type of problem. One suggestion is have them pressure test the CAC but that is only one part of the system.

Thanks

Richard