New X12- Oil Leak Mystery

[mmstump]

Our Cummins X12 (2021 coach on its maiden voyage) developed an oil leak in the first 1400 miles. It seems to only leak after driving and was enough to cover our car in oil, but not impact the level or pressure in a meaningful way.

The pan is fine. It appears to be leaking from the crankhouse breather but the pressure is fine.

The oil appears to have been over filled. They drained some off, cleaned it up, took it for a test drive and saw the leK again from the breather. The working theory at the moment is that 1) either the excess oil has “contaminated” the crankshaft or there is a damaged baffle in the engine.
They are going to take it apart today.

Curious if anyone here has experience with this type of situation and what you found?

[Jim_HiTek]

Dunno about brand new models but for many years, there was a problem with the RV manufacturer getting the amount of oil correct for their extended dip stick. And it seemed they tended to overfill rather than under fill.

Often, excess oil would be blown out of the 'slobber tube' and owners would extend that tube to beyond the end of the RV. Manufacturers that caught the issue would often remark their dip sticks to show a lower level. This was true for my old '94 Bounder with a Cummins, and my '02 Winnie with a Cat.

These days, there is no slobber tube, but I'd bet the RV mans. are still overfilling. What needs to happen I suppose is someone needs to research how much oil the Cummins actually needs, then the oil that's actually in there dumped and measured for how many qts are there vs the dip stick marking. Then like in the old days, the dip stick needs to have the old settings ground off and new marks scratched into it to show the new, correct, level of oil.

In my '02, Winnebago showed 22 qts (marked on the chassis), the dip stick was obviously remarked at 20 qts so that's all I put in, and I get no blow by onto the front of my towed. The one time I did add 22 qts, because I didn't believe the remarked dip stick, it covered the front of my towed. Learned a lesson there.

OR, it's something else! Good luck!

[mmstump]

Very helpful. Quite a messy experience with such a simple cause and messy effect. Thanks for sharing.

[vito.a]

That would be very disappointing in a new coach. I hope they get it fixed right away.

[tom chelbana]

Do check dip stick tube. Make sure tube is tight and the cable is screwed on to the tube is
tight. Our Essex with 500 ISM had a number of times problem with oil leaking and the dip stick tube was the issue.

[mmstump]

Originally Posted by tom chelbana

Do check dip stick tube. Make sure tube is tight and the cable is screwed on to the tube is
tight. Our Essex with 500 ISM had a number of times problem with oil leaking and the dip stick tube was the issue.

Will do. Thanks for that! They took the valve cover off, cleaned it up took it for a test drive measuring crack shaft pressure and all seemed good. Unfortunately after cooling a bit it began leaking again. They were able to locate the one available new cover in the country and are shipping it in to replace on Tuesday and will repeat the process. That said, the techs are not very hopeful that is the issue and believe they will need to tear the engine apart. So hopeful that is not the case.

We discussed the idea of also draining all the oil and refilling based on actual size vs dipstick. He also wondered if the dipstick had been wrong...so he is going to do that. I will add this to the consideration list for him. He seems to be a very good trouble shooter and very open to ideas.

Thanks to both of you for taking the time to respond it has been very helpful.

[mlabouf]

mmstump, Following up on a 20 month old thread. I have a 2020 MADP 4018 with the Cummins X12 purchased used in January 22. I've had a problem with oil accumulating on the rock guard and on my car trailer towed behind the coach.

When I took it for service at a local shop (nearest certified spartan shop is a 2 hr dive) the issue was diagnosed as a leak from the brake hydraulic reservoir (even though level was still in spec) and repaired.

A couple of days after our most recent trip, I noticed oil had driped n the ground at the rear right side of the coach and that the rock guard was again saturated.

Diagnosing myself, it is evident that the oil is coming out of the top of the dipstick tube. Oil level is about 1/2 inch over the top of the full line, so I'm expecting it was simply overfilled by the presale service done at the selling dealer.

After reading your post, I'm hoping its not something more. What was the final conclusion on the oil leak on your coach?

[glen_423]

I have a 2020 MA with a X12. I did a factory pickup and mine was also overfilled from the factory. I checked it at the factory and did notice it was a little overfilled but the coach was not in a very flat location when it did so I felt it was just fine. After I picked it up I only drove it about 100 miles to our first location (I did not have any leaks). Once parked and leave on the jack I rechecked the level and it now read way over filled. So I drained about 1 1/2 gallons out of it and rechecked it. It was just a little over filed so I left it alone and everything was good. I suspect I was still about another 1/2 gallon over filled

When I did the first oil change I put in the correct amount of 10 1/2 gallons and it was perfectly at the top of the fill line (I do the final check with the coach leveled on the jacks). I have noticed from multiple checks on the road that the oil level is VERY sensitive to how level the coach is. It can read from over filled to about 1/2 down the full line with a little coach lean. I have never had a engine this sensitive

I put on about 5K-10K between my yearly oil changes and it appears this X12 is using 0 oil.
So when I do my oil checks I don’t get to worried about the oil if it is not perfectly on the full line

[mlabouf]

Originally Posted by glen_423

... I have noticed from multiple checks on the road that the oil level is VERY sensitive to how level the coach is. It can read from over filled to about 1/2 down the full line with a little coach lean. I have never had a engine this sensitive

Thanks glen_423. Coach was on a level surface when I measured the oil level.

[mlabouf]

Originally Posted by mlabouf

... the issue was diagnosed as a leak from the power steering hydraulic reservoir ...

Power steering reservoir, not brake

[mmstump]

Originally Posted by mlabouf

mmstump, Following up on a 20 month old thread. I have a 2020 MADP 4018 with the Cummins X12 purchased used in January 22. I've had a problem with oil accumulating on the rock guard and on my car trailer towed behind the coach.

When I took it for service at a local shop (nearest certified spartan shop is a 2 hr dive) the issue was diagnosed as a leak from the brake hydraulic reservoir (even though level was still in spec) and repaired.

A couple of days after our most recent trip, I noticed oil had driped n the ground at the rear right side of the coach and that the rock guard was again saturated.

Diagnosing myself, it is evident that the oil is coming out of the top of the dipstick tube. Oil level is about 1/2 inch over the top of the full line, so I'm expecting it was simply overfilled by the presale service done at the selling dealer.

After reading your post, I'm hoping its not something more. What was the final conclusion on the oil leak on your coach?

I am sorry you are dealing with an oil leak. It can be maddening. I Also hadn’t realized I didn’t comeback to do a final update. In our case the tech drained and refilled the oil to the proper levels but that did not resolve the issue. Cummins engineers had them change the valve cover to rule out a defect in the breather (which is integrated into the cover). Much to our techs surprise that did the trick. There was a defect and the issue was resolved. We have had no more oil leaks since. Now unrelated, we had a coolant leak from a faulty weld on the surge tank which resulted in a similar type of mess. The replacement tank had the same type of defect so a shop in Tallahassee worked with Spartan to allow them to re-weld the tanks vs trying yet a 3rd and potentially faulty tank. That has also been holding up well.

Best of luck sorting out the leak. I would recommend having Spartan connect you/your tech to Cummins to troubleshoot. They partnered well with the techs on the ground and with the engineers and specialists at Cummins. Our tech, who was incredibly competent and experienced, was expecting to have to take the engine apart to figure out what was going on as he did not believe the valve cover could really be the issue. Had Cummins not worked it out on their end we could have had a much more difficult situation to deal with on ours.

[mlabouf]

Originally Posted by mmstump

...I would recommend having Spartan connect you/your tech to Cummins to troubleshoot...

Thanks for the reply mmstump. Will do.