Oil Changes - How often?

[nomadicherd]

Hello All!

I have a 99 Diesel 38 foot Class A and I've never owned a diesel before. How often should you get your oil changed?

Thanks!!!

[geordi]

Well the obvious and snotty answer is "it's in the owner's manual".... BUT the reality is that if you ask 5 people on just about any forum, what is their thought on oil... You are likely to get 7 opposing answers.

For most diesels the oil changes will be at least 5k miles, and can be as many as 15 or 20k miles, maybe more. These are usually heavy truck engines that aren't doing the kind of work that they normally would do, so oil changes can be more for time rather than mileage. That said... If I had to just guess, I'd say 5k miles and no more than 2 years, and use a quality synthetic like Mobil 1 Delvac or Shell Rotella T6. That's what all my current diesels get, and they run great.

But you are going to want to look in the manual or ask the manufacturer of your engine what their answer is.

Who made the engine?

[Ray,IN]

Cummins says @ 15,000 mi. for my engine or annually, whichever comes first. Mine gets changed + oil filter every November.

[OldHatt45]

Generally speaking, if you store your RV for the Winter, then I have always changed my oil right before storing. Reason is that you don't want to leave any corrosive fluid in the engine over the winter (storage). So my process is to change oil and filter when winterizing. Hope this helps.


Drew

2003 Travel Supreme 40DS02

[TonyMac]

My CAT C7 book says annually or according to a formula that works out to about 12,000 miles. I do my oil and filter annually in the spring; I am still employed and only put on about 5,000 miles/year. I choose to leave old oil in the pan over the winter in favor of running the motor with new oil in the spring. I've seen no professional dictate about WHEN to change, only how often.

[Ray,IN]

Originally Posted by TonyMac

My CAT C7 book says annually or according to a formula that works out to about 12,000 miles. I do my oil and filter annually in the spring; I am still employed and only put on about 5,000 miles/year. I choose to leave old oil in the pan over the winter in favor of running the motor with new oil in the spring. I've seen no professional dictate about WHEN to change, only how often.

My Cummins ISC engine manual says to change oil prior to long-term storage due to acids that accumulate during use. That's why I change oil N filters each November.

[LPerry]

Originally Posted by geordi

Well the obvious and snotty answer is "it's in the owner's manual".... BUT the reality is that if you ask 5 people on just about any forum, what is their thought on oil... You are likely to get 7 opposing answers.

For most diesels the oil changes will be at least 5k miles, and can be as many as 15 or 20k miles, maybe more. These are usually heavy truck engines that aren't doing the kind of work that they normally would do, so oil changes can be more for time rather than mileage. That said... If I had to just guess, I'd say 5k miles and no more than 2 years, and use a quality synthetic like Mobil 1 Delvac or Shell Rotella T6. That's what all my current diesels get, and they run great.

But you are going to want to look in the manual or ask the manufacturer of your engine what their answer is.

Who made the engine?

This aligns pretty well with my opinion too, except in my motorhome I use rotella t4. It's a significant cost savings and I figure the driveline will be just about broke in when this thing goes to the junkyard someday. No sense in putting expensive synthetic in something that'll Outlast the vehicle by a factor of 3.

Also a consideration is that synthetic can cause leaks in older types of seal materials. 90s ish is when a lot of that stuff switched over to better material.

[geordi]

Originally Posted by LPerry

This aligns pretty well with my opinion too, except in my motorhome I use rotella t4. It's a significant cost savings and I figure the driveline will be just about broke in when this thing goes to the junkyard someday. No sense in putting expensive synthetic in something that'll Outlast the vehicle by a factor of 3.

Also a consideration is that synthetic can cause leaks in older types of seal materials. 90s ish is when a lot of that stuff switched over to better material.

The "synthetics cause leaks" story is an old wives tale now, that was b/c the seals were made from natural rubbers back-in-the-day and the conventional oil (or the sulfur in it) caused the rubber to swell up which was fine... Until better and cleaner oil came along that didn't have that in it. The same thing happened with the conversion to ULSD because of the removal of the sulfur from the fuel, and the result was fuel pump leaks. I had it happen to me on a VW diesel in that era.

That was 17 years ago now, and the chances of some of these engines experiencing leaks b/c of changing to synthetics is minimal at best.

My coach is a 2003, so IN THEORY that could still be an issue... But I doubt it will be. On a sump of this size (4 gallon if I remember correctly) I can see the cost benefit of using T4... Although the TOTAL mileage I have put on this coach since I bought it has only been about 3500 miles... In 6 years. That would be a TRAGIC waste of oil to be changing it yearly just because of the age. I have *never* changed any oil based on age and never had a problem because of that... But I also pretty much only use synthetics b/c I have personally experienced their impressive protective qualities.

I had an old Lincoln years ago that for a while had an AIR-COOLED V8 engine in it. (No, it wasn't supposed to be!) It had a pinhole leak in the cooling system that I couldn't ever find - and it overheated to completely dry about 6 times. But the engine kept on going b/c it was running Mobil 1 Synthetic. It did eventually pick up a cylinder rattle (probably a bearing dying) but I was a lot younger then and didn't know what I know now about engines and engine work. That the engine put up with that level of abuse for as long as it did was amazing.

[CoachC]

Originally Posted by Ray,IN

Cummins says @ 15,000 mi. for my engine or annually, whichever comes first. Mine gets changed + oil filter every November.

X2 what Ray says. I have yet to hit 15K miles in a year but change annually along with my annual inspection/maintenance. Have this done at the Spartan Factory Service Center. Used to be in November but have moved to October last 2 years. This fits my family schedule better.

Best of luck on your new diesel adventure. I think you'll like it.

Cheers

[eddieelk]

I have read on the Forum that it costs from $600.00 to $800.00 for the annual diesel fluid changes. That's why I am on my 4th gas engine MH. I changed my oil today at a cost of $22.00 and one pair of rubber gloves. I paid $10,000 for my current Pace Arrow, and in 4 years have replaced windshield, tires, belts, brakes, shocks, batteries, water heater tank, and other miscellaneous parts, costing less than $4,000.00. Be sure and have sufficient tools to start your collection, because we all learn that the only tool that you don't have, is the one that you need. Eddie Elk.

[geordi]

Originally Posted by eddieelk

I have read on the Forum that it costs from $600.00 to $800.00 for the annual diesel fluid changes. That's why I am on my 4th gas engine MH. I changed my oil today at a cost of $22.00 and one pair of rubber gloves. I paid $10,000 for my current Pace Arrow, and in 4 years have replaced windshield, tires, belts, brakes, shocks, batteries, water heater tank, and other miscellaneous parts, costing less than $4,000.00. Be sure and have sufficient tools to start your collection, because we all learn that the only tool that you don't have, is the one that you need. Eddie Elk.

Oh, yes... Diesels are SO much more expensive to maintain than a gasser.... If you believe the nonsense from the person who wants to sell you a much higher profit margin gasser.

The reality is a bit different. They have the same basic fluid needs, but the BIG difference is that since a diesel coach is based on the same engine as a diesel truck... You can have a truck servicer work on it if you don't want to do it yourself. The BIGGEST mistake is to take any coach to an "rv service shop" b/c that is how your wallet gets emptied!

Camping world charges something like $95 for a "Generator oil change" and what do you know... It's one plug under the body (or an oil extractor if you want to get fancy) and 1 spin-on $10 filter.... And up to 3 quarts of oil.

That's robbery and they know it - "but it's an RV" like that somehow justifies the huge upcharges.

I can (and will be) taking my coach to a Petro station or possibly a Loves, and have the truck service bay there do the oil change. Petro quoted me about $250 for an oil change and chassis lube, AND replacing all the filters on the engine! Now THAT is a smoking good deal. I have to see what the synthetic upcharge would be, b/c I know the retail on the filters is like $20 each and I presume there are 5 of them - 2 fuel and 2 oil, plus the air filter. Synth oil is $30/gallon retail... So they have to be making some profit somewhere in there.

The only reason I'm thinking of having them do it, is just their familiarity with big vehicles and knowing what they are looking for. Otherwise I could certainly do it myself.

[LifeSalt]

Heck, I change my own oil. No different than a car or truck. Just huge filters and my rig takes 6gals of oil. Save a ton of money by DIY....... Your manuals will show you what filter is what.....

[Mr_D]

My ISX manual states yearly or every 15,000 miles. It hasn't been a year since the last (of 3) in frame rebuilds. Just for giggles I did an oil sample at about 5,000 miles and all looked good except the magnesium was high. But I'm not worried as it's basically breaking in a new engine. Will do an oil/filter change after I get back from Quartzsite/Tulsa next year.

[HJLowell]

Be sure to always change the Coolant and Hydraulic fluid filters also.

Manytimes overlooked.