I've been looking at different sources trying to determine the correct time to change oil on my Cat C-12 and so far have been unable to find anything that refers to the time between changes...it all relates to miles and fuel consumption. This seem to be in conflict with the "opinions" that state a yearly change is necessary.For example, in an application less than 80,000 lbs, more than 7 mpg, and less than 20% idling time, the oil change interval is 25,000 miles. As MPG go down so does the interval. Oil analysis at 10,000 mile intervals with some discourse on what to look for in the results.Cat Maintenance ScheduleSo, unless there are some other Cat documents referring to a time between changes, what are most folks doing.I sorta figure Cummins has a similar spec.Clarity would be appreciated.

Here's what I would do. Go toBlackstone Labsand get the free sample kit.

CAT recommendation for Rv is 1 year. Clean oil is a critical component to the engine. The cost is minimal compared to a filed HEIU, Injector or other component failure.

X2. Cat says one year or 10K miles, whichever comes first.I went two years,but only 8K miles and got an engine light because my oil was so dirty it was causing the IAPVC to stick and so I wasn't getting correct pressure to the HEUI (?sp).($190 parts and labor) The service manager at the CAT dealer in Fife suggested that I go to a 5K interval. He also suggested that I do an oil and filter change only at somewhere around 3k and then start the 5K after that. I am getting more blowby than I'd like and that started about the same time as the engine light on our last trip to Vegas and S.D. area.He also suggested that I have the valves adjusted,even though they only have 60K miles since the first one at 47K.

Post your question to the Diesel RV Club in my signature

Thanks for the reply's...is there any documentation from Cat specifically for RV's. Seem odd that there is such a difference.I do like supporting documentation whenever possible to separate opinion from product engineering.

Cat Oil Change Interval | Good Sam Community

ncrowley
Explorer II
Jun 25, 2013
I was told to change the oil once a year so that is what I am doing. I use Speedco. They are great! The prices are much less than anywhere else I checked and they let me watch and ask lots of questions. I also had them change the oil and filter on the generator.
wny_pat1
Explorer
Jun 24, 2013
Actually, looking at table 21, page 193, 15,000 miles is the severe duty OCI for your engine - provided you do not get less than 6 mpg, do not weight more that 80,000 lbs, have a minimum oil sump capacity of 36 quarts, and do not idle more than 40% of the time. Thats pretty simple, don't complicate it!
cjlatour
Explorer
Jun 24, 2013
CAT recommendation is @ specified mileage or a least annually (no matter the mileage).
bluwtr49
Explorer II
Jun 24, 2013
Yep, might just give Cat a call and check with them. Having the oil changed yearly certainly is not a budget buster but I also dislike throwing $$$ down a drain if it's not necessary.

I guess the yearly thing just doesn't make sense if a oil analysis shows no abnormalities. Anything like moisture, dirt, soot, and etc would certainly be indicated. Good topic for Cat.
wilco
Explorer
Jun 24, 2013
FWIW. Had Cat 3126 for 12 years. Got similarly confused about change intervals early in the game and decided that with my usage (<5000 mi/yr) I would change the oil annually and that is what I did. Seemed like a decent compromise amongst all the different advice and nothing bad happened.
wny_pat1
Explorer
Jun 24, 2013
jferre9570 wrote:
Call Caterpillar directly, with your engine serial number, and they will tell you "straight from the horse's mouth" as it were.
1-800-447-4986 or e-mail Call_Cat@cat.com (from Cat website)

X-2!!! and the folks at the Cat RV Club should be more than willing to help you out to! And make sure you calibrate your dip stick the first time you change the oil!!!
jferre9570
Explorer
Jun 24, 2013
Call Caterpillar directly, with your engine serial number, and they will tell you "straight from the horse's mouth" as it were.
1-800-447-4986 or e-mail Call_Cat@cat.com (from Cat website)
bluwtr49
Explorer II
Jun 23, 2013
Thanks for the reply's...is there any documentation from Cat specifically for RV's. Seem odd that there is such a difference.

I do like supporting documentation whenever possible to separate opinion from product engineering.
wallynm
Explorer
Jun 23, 2013
Post your question to the Diesel RV Club in my signature
Bigdog
Explorer
Jun 23, 2013
X2. Cat says one year or 10K miles, whichever comes first.I went two years,but only 8K miles and got an engine light because my oil was so dirty it was causing the IAPVC to stick and so I wasn't getting correct pressure to the HEUI (?sp).($190 parts and labor) The service manager at the CAT dealer in Fife suggested that I go to a 5K interval. He also suggested that I do an oil and filter change only at somewhere around 3k and then start the 5K after that. I am getting more blowby than I'd like and that started about the same time as the engine light on our last trip to Vegas and S.D. area.
He also suggested that I have the valves adjusted,even though they only have 60K miles since the first one at 47K.