Community Forums

Jeff753 · 07-12-2014, 10:38 AM

I have a 2001 cummins 8.3 ISC Monaco dynasty. For a year on the flat roads of Florida I used little to no oil. Last year I noticed if I ride the exhaust brake down a long grade I use oil. Went from Florida to Michigan and used 84 oz of oil. I'm going to take it to cummins but I'm interested in what they should look for.

Also (possibly related) before I started to use oil I had a 9" crack in the CAC and only 7 pounds of boost. With the new CAC I get 21-23 ponds of boost. Could the oil be turbo related since the turbo is now developing more boost. Maybe it's not the exhaust brake but higher turbo usage on the climbs?
Fixing the CAC and oil usage increase happened at the same time.

NHRA225 · 07-12-2014, 10:49 AM

Does your Engine have any Blow by like puking oil out of the vent tube ?
How many miles on the Engine ?

H. Miller · 07-12-2014, 10:51 AM

The turbo is not developing more boost, only that the boost is now being captured and a true measurement is being given now that CAC leak is fixed. There is an engine oil line going to the turbo but if it leaked that much oil, the rear of the MH would be black with puddles of oil under the engine. Ditto for most any leak. It's got to be burning it somehow. Does tailpipe "soot" look normal?

Dr4Film · 07-12-2014, 10:53 AM

I would check your oil breather tube that hangs down from the engine. See if it is really wet with oil. And do you have oil all over whatever you may be towing?

Your 21-23 boost values are normal for that engine. You also may be getting some Blow-By but the only way to tell is through a couple of Blow-By tests.

On a trip from Alaska back to the lower 48 in 2010 I was losing oil and it was being blown out the oil breather tube only when pulling grades.

The Cummins shop in Oregon did nothing for me except take my money for the Blow-By tests.

A few months later I was in the El Paso TX Cummins shop and after explaing my situation with the oil breather tube he suggested that I change out the old oil breather to an upgraded version. I followed his advice, they ordered it and had it installed the very next day.

Problem solved. I no longer blow oil out of my breather tube.

If you are interested, I can look up on the old sale receipt to see exactly what the part number is and cost.

Dr4Film ----- Richard

Jeff753 · 07-12-2014, 10:01 PM

I've never seen any wet oil or drips below the coach. I'll check the tail pipe soot.

Jeff

Jeff753 · 07-12-2014, 10:04 PM

Quote:

Originally Posted by Dr4Film

I would check your oil breather tube that hangs down from the engine. See if it is really wet with oil. And do you have oil all over whatever you may be towing?

Your 21-23 boost values are normal for that engine. You also may be getting some Blow-By but the only way to tell is through a couple of Blow-By tests.

On a trip from Alaska back to the lower 48 in 2010 I was losing oil and it was being blown out the oil breather tube only when pulling grades.

The Cummins shop in Oregon did nothing for me except take my money for the Blow-By tests.

A few months later I was in the El Paso TX Cummins shop and after explaing my situation with the oil breather tube he suggested that I change out the old oil breather to an upgraded version. I followed his advice, they ordered it and had it installed the very next day.

Problem solved. I no longer blow oil out of my breather tube.

If you are interested, I can look up on the old sale receipt to see exactly what the part number is and cost.

Dr4Film ----- Richard

I read cummins moved the breather tube outlet from the top to the side of vice versa around 2001. I've also read of a filter/return or something they add to the slobber tube to return the oil. Is that what you had done?

Jeff

Dr4Film · 07-13-2014, 07:12 AM

Quote:

Originally Posted by Jeff753

I read cummins moved the breather tube outlet from the top to the side of vice versa around 2001. I've also read of a filter/return or something they add to the slobber tube to return the oil. Is that what you had done?

Jeff

Not sure how different the ISC 350 engines are back then but my 2002 coach was delivered in 9/2001.

The Cummins shop in El Paso TX removed the OEM Stock Oil Breather fixture and installed a modified upgrade unit right back in the same location that allows the oil to return to the oil sump pan quickly versus the old one which would just blow the excess out the slobber tube.

They also installed a new longer slobber tube for me which took it well below the rear mud flap. I have since trimmed it back a little as they were overly generous when they did that.

I will dig out the paperwork sometime today that I got when they did all of that, scan it and re-post. The cost was right around $400 if I remember correctly. It was back in 2011 so don't quote me.

Dr4Film ----- Richard

Dr4Film · 07-13-2014, 08:33 AM

Jeff,

OK, here's the deal.

According to my invoice the Upgraded Blow-By Oil Breather Kit is part number 3968382 and was $140. Of course there are other parts needed to get the thing installed correctly like gaskets, hoses and they had to change out one adapter where a short hose from the breather kit was attached to the turbo tubes.

I have attached the Cummins QuickServe sheet showing the Upgrade Kit. They had to order it and did the installation the next day.

Since that day I have never had anymore oil coming from the slobber tube.

Dr4Film ----- Richard

Jeff753 · 07-15-2014, 06:36 PM

Organizing my files last night I had a closer look at my last two oil changes on my 350 ISC 8.3 cummins
On my last oil change in cummins Ocala I was charged for 24 qts of oil. Am I correct that it should take 22 qts or a little less since it's not a dry engine?

Jeff

Dr4Film · 07-15-2014, 07:02 PM

A Cummins ISC 350 HP diesel engine when completely dry should use 6.3 gallons of oil.

An oil change with a new filter should only need maybe 20 quarts of oil or so maybe a little more.

At Speedco where I have most recently been going I always tell them to put in 18-19 quarts. Then run the engine to circulate the oil through everything and then check and bring it up to the full line.

That way it never will get overfilled which will make a real mess of your rear end and the toad.

Dr4Film ----- Richard

Coma · 07-16-2014, 06:31 AM

I put 24qts in mine. Over the course of a few thousand miles it will use about 2 qts. The year I drove it 11k miles I had to add two qts. Some diesels use a little more oil than others. If you are not dripping or blowing out enough to see on engine or toad then check the Cummins spec.

There is also a happy spot on the dip stick the engine will find and oil will go away till it's there.

The Dr. is spot on also. There was a recall about that kit, although I believe it has long expired.

Papa_Jim · 07-16-2014, 04:43 PM

Quote:

Originally Posted by Coma

I put 24qts in mine. Over the course of a few thousand miles it will use about 2 qts. The year I drove it 11k miles I had to add two qts. Some diesels use a little more oil than others. If you are not dripping or blowing out enough to see on engine or toad then check the Cummins spec.

There is also a happy spot on the dip stick the engine will find and oil will go away till it's there.

The Dr. is spot on also. There was a recall about that kit, although I believe it has long expired.

Agreed. Our engine has a happy spot on the dip stick. It's just above the Add mark. Keep the oil level there, and the engine will burn no oil. We have slightly over 5000 miles since our last oil change, and the engine has burned absolutely no oil.

However, if I decide that the oil level must be kept at the Full mark on the dipstick, the engine will burn oil like crazy.

Jim