Oil blowback at Oil fill tube ISL400

[mandms59]

All,

This just started 2 days ago on our trip.  Yesterday halfway along our route we pulled over by a nice lake in SW WA after coming over White Pass.  When I went back to check out the TOAD I noted the right side had some oil splatter marks.  I opened up the access panel on back of our 07 Diplomat and noted that there was oil streaked on the cover and side walls plus the dip stick and Oil filler tube.  Thinking I had not re-seated the dipstick completely that morning after checking oil & thought it may have come from that location blowing out small amounts of oil in compartment - I re-seated dip stick it cleaned off everything in the compartment dipstick/oil fill tube/Air Filter sensor.... and continued on to the final destination.  I did not see any more splatter on car once we arrived... so figured problem was solved.  

Today we drove straight through to our next stay.  When I got here and went back to unhook car... well there was more spray on car's right side than yesterday.

Opened up the right access panel and could see that there was a couple drips coming from the bottom of the oil fill tube where extension tube slides in and out ( forgot to take photo at that time) ...  I wiped off a few areas so I could see if the was a hole somewhere in the fill tube or connection points (nothing I could readily see). 

At this point not sure if it is intermittent problem (e.g. under higher pressure loads climbing over the med uphill grades that some oil residue is being pushed out of fill tube seal area and then dripping down to mudflap where the wind catches it and then gets flung onto right side of car)

 

Or is this indicative of a larger issue -  something bigger than fill tube seal leak ???

Has anyone run into this problem?

Is there an easy fix - e.g. is the copper/rubber ring around extension tube replaceable?  Part number?

I attached a compiled photo markup sheet for reference.   we are not traveling again until 26th; so other than starting engine and have wife increase throttle while I stand in back  to see if I see anything leaking... next test would be Monday's trip south into ID.

I was going to wrap filler tube at junction point with duct tape to see if I could isolate it that way....

Thanks in advance for recommendations/fixes further T/S ideas.

 

R/ Mark

 

 

Edited July 25, 2021 by mandms59

[Rick A]

Have you noticed a drop on the oil level or a drop in oil pressure? 
How much oil do you think you are blowing out. 
No smoke and noises is a very good start. 

[Guest Ray Davis]

Probably over filled with oil.  Dip sticks are often wrong on these coaches.  Was the oil changed recently?   Any idea how much was put in?

[mandms59]

13 hours ago, Rick A said:

Have you noticed a drop on the oil level or a drop in oil pressure? 
How much oil do you think you are blowing out. 
No smoke and noises is a very good start. 

Oil pressure has been consistent in mid 50's even with the blow back issue the past  1 1/2 days. I have not been a hawk on watching pressure during descents/exh brake usage to see if it rises appreciably; but will do so when we depart tomorrow.

I will have to check the dipstick again tomorrow when I am off the jacks to get accurate reading; After the first day I thought it was sitting at same level as before (about 1-2 quarts low)but it is tough to tell on that stick as Ray mentioned above.

There have been no unusual noises, out of ordinary readings on gauges or Aladdin Monitoring page during those instances.  We are coming up on our oil and fluid filters replacement/maintenance here shortly -as we full time was planning to have done at the Cummins Service Center in Boise ID next week.

Should I be inquiring about cylinder compression test? 

Does anyone have any other T/S items I could tackle on my own? 

Could a clogged/restricted crankcase breather filter/tube contribute to problem?  I am 3rd owner of coach so no complete records from previous owners... and do not believe it has ever been replaced we are at 87K on engine.

 

[Ivylog]

Assuming a 06 engine you probably have a crankcase vent tube filter that need replacing.

[Rick A]

10 minutes ago, mandms59 said:

Oil pressure has been consistent in mid 50's even with the blow back issue the past  1 1/2 days. I have not been a hawk on watching pressure during descents/exh brake usage to see if it rises appreciably; but will do so when we depart tomorrow.

 

I will have to check the dipstick again tomorrow when I am off the jacks to get accurate reading; After the first day I thought it was sitting at same level as before (about 1-2 quarts low)but it is tough to tell on that stick as Ray mentioned above.

 

There have been no unusual noises, out of ordinary readings on gauges or Aladdin Monitoring page during those instances.  We are coming up on our oil and fluid filters replacement/maintenance here shortly -as we full time was planning to have done at the Cummins Service Center in Boise ID next week.

Should I be inquiring about cylinder compression test? 

Does anyone have any other T/S items I could tackle on my own? 

Could a clogged/restricted crankcase breather filter/tube contribute to problem?  I am 3rd owner of coach so no complete records from previous owners... and do not believe it has ever been replaced we are at 87K on engine.

 

I have a 2005 Diplomat and my oil pressure runs at 35 psi. My clock sits at 51000 miles. The engine manual says 30 psi is the regular pressure at normal revs, and 20 psi at idle. It seams your pressure is under the regulated Max of 75 psi. 
Pressure in the crank case would dramatically increase if you had a cylinder issue. I doubt that’s the problem as smoke would almost be effect. I almost think Ray has a good point. 
Any leak would result in your issue. 

[Robert U]

It sounds like you have a clogged crankcase breather. Possibly a mud dobbers nest. I would check the breather tube first. It is normally next to oil filter.

Bob U

[mandms59]

UPDATE -

I added about 2.0 qts of oil which based on dipstick markings.   I am now getting 65 PSI at idle & rises to above 75 psi if I bring revs up to 1200... so I am estimating that the blowout was more than what oil I saw on the car.  And that the system is not able to regulate below 75 as Rick A mentioned below and confirmed in Cummins manual...

On 7/25/2021 at 10:41 AM, Rick A said:

I have a 2005 Diplomat and my oil pressure runs at 35 psi. My clock sits at 51000 miles. The engine manual says 30 psi is the regular pressure at normal revs, and 20 psi at idle. It seams your pressure is under the regulated Max of 75 psi. 
Pressure in the crank case would dramatically increase if you had a cylinder issue. I doubt that’s the problem as smoke would almost be effect. I almost think Ray has a good point. 
Any leak would result in your issue. 

This leads me to believe that it is much more severe problem ($$$) than clogged breather tube  - which I was not able to find looking thru engine hatch above or underneath;  maybe not looking for correct item....  Easily found Oil filter and can trace return line from Turbo charger to crankcase... but did not find anything else from crankcase on either side...

We are about two hrs away from Spokane Cummins dealer...  Guessing that is my best option to bring it to for further checkout/diagnosis - compression check??

Has anyone dealt with them or recommend another shop in area... we are currently about 35 miles south of Lewiston ID at state park campground. 

Recommendations/suggestions/guidance greatly Appreciated

R/ Mark

 

 

[Rick A]

My thoughts are you overfilled it with oil. The oil pressure is a telltale and it’s spewing oil as and where it can. It might even cause smoke as she sucks on the down stroke. 
The oil pressured you are quoting would make me nervous in my Diplomat. 
 

[mandms59]

40 minutes ago, Rick A said:

My thoughts are you overfilled it with oil. The oil pressure is a telltale and it’s spewing oil as and where it can. It might even cause smoke as she sucks on the down stroke. 
The oil pressured you are quoting would make me nervous in my Diplomat. 
 

I forgot to add that on our short travel yesterday ... PSI stayed in normal ranges  until about 5 miles out from our stop -- while idling at a flagger checkpoint the Idle PSI went down to 20 PSI;  that got me nervous as I have never seen it that low.  When we got to campground I checked oil dipstick and thought it was 1-2 quarts low on stick so I added 2 quarts to bring it up to within range last night.  Then this morning started it up and got 65 PSI....  If I did overfill it - take it the simplest way would be to try and drain out some oil from drain plug without making a big mess in campground.

[Ivan K]

Just consider that your oil pressure is dependent on its temperature so starting with cool oil can easily do 65 psi idling. 25 psi idling hot is good for me. I also doubt that crankcase pressure has any effect on oil pressure past the oil pump. Feel what kind of blowby you get from the puke hose, there should be some but if nothing, someone already mentioned your crankcase filter if you have one, I don't.

[Rick A]

Something strange going on. You filled it to the dip stick mark.
It retained PSI.
Then you stop and PSI drops. 
You then add oil because level has dropped.
You are loosing significant oil somewhere. 
I think if you can find the leak it’ll keep it’s pressure and maintain the oil level. 
I don’t think from what you say, that overfilling is the cause.

You know the effects, loss of oil and loss in PSI. They correlate. 
You know the oil is on the car.
Just need to determine the where the leak is. There must be clear signs of this loss. 
 

[Ivylog]

You could be 2 gallons low and the pressure might be 2 psi lower than normal because the oil temp is slightly higher.

Slightl over full will not hurt anything.

[Rick A]

The oil level is an engineered condition. 

 The oil will be whipped into a thick aerated foam by the high rotations made by the crankshaft. This changes the lubricating qualities of the oil. Vehicle manufactures usually advise against low oil levels (obviously) but they also recommend against over filling. 

 

[Chieflou]

Mark,

  I keep going back to your initial complaint:  oil coming out the dipstick tube.  That specific issue has no relevance to oil pressure.  Oil coming out tube will only be caused by higher than normal crankcase pressure (blow by) which goes to what others have already mentioned -- restricted crankcase breather filter or tube. Fix that and your dirty toad problem should be resolved. 

  Then regarding oil pressure.  As has been mentioned, overfilling could be a factor there.  Specifically, as Ray D. posted, your dipstick markings could be inaccurate, a common issue I've noted others mentioning on the forums.  Inaccurate markings could lead you to overfill which will cause numerous problems.  And the engine will almost certainly "get rid" of that excess oil all on its own.  Before spending money on diagnosis, you could confirm or eliminate this possibility by draining your oil then carefully measuring and refilling with the amount of oil stated in your owners manual.  After filling, check your dipstick. If accurate, press on with further professional diagnosis.  If stick is off, use a fine-cut file to create a new (accurate) full mark on the side of stick opposite the factory marks.

Hope this helps, best regards,

  Lou S.

[Guest Ray Davis]

We have some excellent advise so far.   I agree with Chieflou except for referring to the manual since it may be wrong and may be the source of the problem. 

Bill D our founder RIP and other old timers that had already fought this war told us repeatedly that the literature is often wrong, that it quoted oil capacity for a new        and empty engine.

Since we cannot drain the engine completely,  some oil will remain,  so if we use the amount for an empty engine we will always overfill.

The engine will blow the excess oil out of the breather tube which may be where the oil is really coming from .if it's to full.

Oil change paces are known to do the same thing.  They use the same inaccurate literature,  even Cummins.  They just Google engine oil capacity.

Assuming the OP has an ISC 8.3,  hopefully someone with the same engine will chime in with the correct info.

[Chieflou]

So Ray, not disagreeing with you, but enlightened -- the manual accuracy question.  So how do we (any of us) discern with confidence the proper oil volume?  I understand the issue of Cummins not being able to speak to technical details of items/systems "hung" on Cummins engines by the coachbuilders.  But the oil pan (only variable to affect oil volume spec on any given engine) was definitely a Cummins installed component.  That said, can Cummins not provide definitive (read trustworthy) oil volume specs for a given engine they manufactured?

Then on the drain/measure/refill advise I offered before.  I neglected to state that you should replace oil filter with new as part of that process. Because there will be a significant volume of oil in the filter to throw measurement off.  

Finally, and again, not a disagreement (not that much expertise) but wouldn't the manf recommended oil fill specs be based on an already prelubed engine?  If not, it makes no sense.  That would mean every one of us should be trying to ascertain the volume of oil in our prelubed/drained engine then deduct that volume from the manf recommended fill spec.  Looking for more enlightenment.

[Guest Ray Davis]

Lou,  I should have looked closer.  I see you are a Vet and new on Monacoers.   Thanks for your service and welcome to the group.

I certainly wasn't disagreeing with you,  only pointing out the dilemma in determining the correct amt.

Cummins says 6.3 gals       http://www.rvtechlibrary.com/engine/ISC350_specs.pdf    Again, that's more than likely a new dry engine.

Heres a thread where they say 5 gals       https://www.irv2.com/forums/f104/isc-350-oil-capacity-230891.html

another thread   https://www.irv2.com/forums/f123/oil-capacity-197561.html    here a poster says his takes 21 qts and the oil change place always put 24 qts 3 of them ends up on his car.

There is a good chance that is what happened to the OP.   

[Chieflou]

Ray,

Thanks much for your thanks.  I feel thanks are needed much more for those currently serving (my son included).  Very tough time to be in the military right now ... as active duty suicide rates demonstrate.  Prayers please for all those in uniform now.  That includes members of our police forces who are these days serving in a capacity every bit as life threatening as our military combat troops.  And being horribly treated by some as the serve.

Sorry for the digression, back to oil. 

I was not at all offended by your comments, my post was meant to thank you for enlightening me to the dilemma.  And it seems the dilemma is, to this day, unresolved, yes?  I like the idea in one of your posted links about contacting Cummins with the oil pan P/N for a capacity readout, cause the pan is really what determines that number.  Have not had any issues regarding oil with my Camelot so far, but it I ever do, the knowledge gained from this thread will help guide me to a resolution.  

Thanks to all for the wisdom and information.

Best regards,

   Lou S. 

[Guest Ray Davis]

Oh boy,  have you touched a subject close to us.  We consider ourselves very patriotic and what's happening to both the police and military is way past troubling           it's freighting.   We have 2 of our family that are policemen.  Every day we pray they come home.  We also have a grandson who always wanted to be police and or military,  how scary is that now days.

The oil level dilemma can't be as gloom as I may have made it seem or we would all be in trouble.  Apparently most dip stick are close to being accurate that it's not a problem.    I use my dip stick when I change the oil,   but I don't try to keep it right on the full mark,   mine seems to settle down some so I've gotten used to letting it show a little low.

I would really like to know if Mark the OP has reached a conclusion.

[mandms59]

All,

We have been in an area with little to no cell reception for our hotspot the last few days.

Thank you for the comments/education and suggestions.  

 

21 hours ago, Chieflou said:

Mark,

  I keep going back to your initial complaint:  oil coming out the dipstick tube.  That specific issue has no relevance to oil pressure.  Oil coming out tube will only be caused by higher than normal crankcase pressure (blow by) which goes to what others have already mentioned -- restricted crankcase breather filter or tube. Fix that and your dirty toad problem should be resolved. 

  Then regarding oil pressure.  As has been mentioned, overfilling could be a factor there.  Specifically, as Ray D. posted, your dipstick markings could be inaccurate, a common issue I've noted others mentioning on the forums.  Inaccurate markings could lead you to overfill which will cause numerous problems. 

  Lou S.

Lou - thanks for input, as we are F/T on the road unfortunately there is not an easy option for draining & refilling oil - hence I end up bringing into a shop to complete the scheduled service fluid change work.

As many have stated (Rick A /Ray /Ivan)... I now wonder if my dipstick markings are off far enough that I am exacerbating one simple issue crankcase breather filter/tube with oil quantity/pressure situation by overfilling to get within marks.

Current plan is to bring it to Cummins as it is in window for Chassis and Generator service that I was planning on in the next month.  I will have them replace crankcase filter/check overflow tube - as I do not have a record of this being done from previous two owners( very limited record keeping).  

This will at least give me a grounded starting point to go forward with known oil level and that crankcase breather filter/tube is in working order.

As I still have limited connection... will read through everyone's posts above again and  make sure not missing something else above. 

Will provide an update once  services are completed above.

R/

Mark

 

Edited July 29, 2021 by mandms59

[Chieflou]

Mark,

  That sounds like an awesome plan.  You won't really be paying for "diagnostic manhours" which can quickly get out of hand, but merely for scheduled service which will accomplish two goals: fresh lube/filter and confirmation of dipstick tube accuracy.  Well, confirmation with the caveat of the dilemma regarding manf fill specs being for dry or pre-lubed engine.  I think that concern is pretty well resolved by numerous comments we've seen here about folks routinely running their levels a bit on the low side.  Your engine won't know if level is a bit low ... it definitely will know if it's overfilled. And if overfull, it will take matters into its own hands, so to speak, to resolve the problem.

The good news I think and hope for you is that you have a common, easily resolved issue.  That you can eliminate that dreadful "major engine repair needed" diagnosis premonition lurking in the back of your mind.

Please keep us all informed with how things go.

Best regards,

   Lou S.

[Guest Ray Davis]

The only thing I can add is ask them to please keep track of how much oil they put in.

When I was at Speedco they just added oil until the dip stick said full.   

[danwegand]

My ISL 2003 Windsor had 198,000 miles the Injector pump went bad, was letting diesel in the oil.  This resulted in the oil being over full and blowing oil out breather tube!  If you can't smell fuel or the fact that your not over full on oil probably not your problem.  Cummins protocol  is to replace nozzles, then fuel lines, and then Pump.

over $10,000 

[mandms59]

All,

Follow-Up/update to the Oil blow back issue.   I ended up being able to get into Cummings in Boise this last Monday.  They completed the routine Generator and Chassis service on the Coach (and gives me a baseline on oil - meaning my oil level should now be at correct level; have noted where that is on dipstick for future reference). 

I asked service manager to replace the crankcase breather element filter as I had no record of it being completed previously by other owners - and check/replace overflow tube for as I could not find it. I mentioned my issue about spitting oil back out oil filler tube, he said that could happen with a restricted crankcase filter/element.

The crankcase breather element was very dirty per tech who worked on MH. I also learned on my ISL400 there is no exterior breather tube - he explained the routing is internal back to crankcase/oil pan to meet EPA changes in mid 2000's .... hence my inability to find the dang tube when searching for it.

We only had a short drive to our next stop; everything seems fine so far - will know more next week when we have a longer drive to next stop including a few medium grades.

Again thanks to all here for their inputs.

V/r

Mark

 

Edited August 4, 2021 by mandms59