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crankshaft oil leak

When we finally reached home after our winter trip and parked on the drive I noticed the next morning about 3 drops of oil on the driveway under the crankshaft pulley area.  It's an ISL400 with 65k miles and has never leaked during our 15k miles of ownership.  I included a pic from underneath.

So, is this a seal leak or something more serious?  How quickly does it need to be fixed - can it go another 500 miles before repair?  Is it an expensive repair?  Any sage advice would be appreciated.
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Mark & Mary Benko
Former coach: 2005 U295 3823
Jeep Cherokee, Honda Fit

Re: crankshaft oil leak

Reply #1 –
Mark, personally I would check the bolts for looseness. Maybe "snug" up all the bolts you can reach in the area of the leak. Don't horse on them, just a little bit of a turn.
Nitehawk,  Demolition Lady, & our NEW master, Zippy the speeding BB cat.
1989 Grand Villa 36' ORED
Oshkosh chassis, 8.2 DD V8
2006 Saturn Vue AWD

Re: crankshaft oil leak

Reply #2 –
Snugging up a little on the oil pan bolts is a good thing to try. How about the oil level of the engine . Is it down any?Did the leak come from higher up? I had a leak on a valve cover on a V-8 once almost took the oil pan off to fix what I though was a rear main. Gam
joseph gambaro
1999 U295 36'

Re: crankshaft oil leak

Reply #3 –
Nitehawk - will try tightening a bit.  I tend to be over zealous and have to be careful.

Gam - oil level is ok, no change.  There is no oil on the topside.  A couple of drops that turned to a spray type pattern to the side but that is it. 
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Mark & Mary Benko
Former coach: 2005 U295 3823
Jeep Cherokee, Honda Fit

Re: crankshaft oil leak

Reply #4 –
On mine (8.3) some of the bolts that hold the timing cover in place came loose and made it look like a crank seal was leaking. I went ahead and replaced the cover gasket which wasn't to difficult a job. 
Randy
1994 U280 40'

Re: crankshaft oil leak

Reply #5 –
If you don't find a leak up higher, I would try an additive like Barrs. See at:  Buy Bars Leak Engine Stop Leak 1010 at Advance Auto Parts

Age hardens seals even if the vehicle has low miles and this will often soften and expand them slightly to stop the leak. I have a MBZ with 440,000 miles that had a severe transmission leak around 300K. Used an additive and it's still nice and dry.

Sure worth a try as it won't hurt the engine but pulling the pan will damage your pocketbook.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: crankshaft oil leak

Reply #6 –
I have had a crankshaft leak on the tranny side for 70,000 miles.  I just clean it up twice a year.  It hasn't gotten any worse.
Regards,
Brett

'99 42' Foretravel Xtreme
'14 Brown Motorsports Stacker
'05 Chevy SSR
'02 BMW R1150R

Re: crankshaft oil leak

Reply #7 –
Quote from: Pierce & Gaylie Stewart –
If you don't find a leak up higher, I would try an additive like Barrs. See at:  Buy Bars Leak Engine Stop Leak 1010 at Advance Auto Parts

Pierce - I'll double check the leak.  If it's at the bottom only then I'll start with Bars and see if it works as I don't plan to get to Cummins for annual service until midsummer.
 
One 11 oz. bottle treats 4 (four) to 6 (six) quarts of oil.  So, do I add 4 bottles at once or just one then drive then add another and drive, etc?
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Mark & Mary Benko
Former coach: 2005 U295 3823
Jeep Cherokee, Honda Fit

Re: crankshaft oil leak

Reply #8 –
I would be tempted to add a couple and see how that goes. You don't have much of a leak yet. Can always add more if needed. Takes a few miles/drives for the seals to soften.

Most of the reviews at that site were positive. You could check other sites or forums to check on different brands and get more user input.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: crankshaft oil leak

Reply #9 –
Thanks Pierce.  It seems like a cheap, no-harm no-foul path to a possible fix. 

If it does not work then I'll get an estimate from Cummins at my annual maintenance.  If Cummins wants too much and the leak gets no worse then I might take Brett's advice and just clean it a couple of times a year.
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Mark & Mary Benko
Former coach: 2005 U295 3823
Jeep Cherokee, Honda Fit

Re: crankshaft oil leak

Reply #10 –
In my opinion, Barrs is not a no-harm product. Anything added to oil will affect the whole engine. I think of Barrs as an emergency fix or a fix to an old engine. I would rather have a small leak than use additives. Could Barrs try to do its thing in a small oil passage? Or affect lubrication? I have no experience with problems with Barrs, just concerned abotu what we put into our engine oil.

Re: crankshaft oil leak

Reply #11 –
Barrs is a chemical only additive with no solid matter to clog anything. It's just a concentrated form of the additives in high mileage engine oils and only acts on the vinyl/rubber seals to soften and make them swell a little bit.

Here is a quote from an article about oil additives:

"Sealers and Seal Swelles is the next topic on the document. It says, "continued use actually softens seals to the point of failure!" Many of the major oil companies make High Mileage Motor oils for vehicles with over 75,000 miles. Seals become hard and brittle over time and can start to leak. No one knows better about this situation than if you have had a seal leak on your garage floor. As seals get older they shrink and leak small drops. In researching High Mileage Oils we found that seal swell additives found in these oils only swell seals 8-10% and do not swell until failure. Major oil companies would not sell motor oils that caused seal failure as the liability would be enormous. Motorists with real bad leaks can rely on aftermarket additives to reduce the leakage. Such suppliers carefully mark their packages to let motorists know how much to use. Almost all of the major oil companies make High Mileage Oils."

Barry makes a good point as everyone should do the research as to what exactly any additive consists of and how it does it's job before blindly pouring it in the crankcase, transmission or PS pump.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: crankshaft oil leak

Reply #12 –
I feel you are better off adding oil until you can fix or have fixed, do not depend on a magic can to solve your issues.
FWIW
Dave M

Re: crankshaft oil leak

Reply #13 –
You said that you checked oil level and it wasn't low. Your going to check for loose bolt on the oil pan and front engine cover. Then your going to clean the whole area. A small amount of oil can make a large mess . I'd just keep a eye on it for now .You know your rig. If it looks that the leak is getting bigger or you start to see a loss on the dipstick I'd then think about adding something .additives well some people love them and some hate them .Did you get any oil on your toad or back end of your coach? Did you change the oil last time or was it done by someone that let the hose slip out of that little filler hole and just wiped down the front of the engine? Gam
joseph gambaro
1999 U295 36'

Re: crankshaft oil leak

Reply #14 –
Barry & Dave - I understand your perspectives & thanks.

Gam - The day after a 500 mile day I found 3 drops on the drive below the area in the the original picture.  No oil on the back of the coach or towed.  Cummins Crosspoint did the last oil change and for the 7500 miles since then there were no leaks until now.  I think I'll tighten if necessary, clean and recheck before making my next move.  It is such a small leak that I can afford some more investigation time before choosing a course of action.

Thanks everyone for your guidance.
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Mark & Mary Benko
Former coach: 2005 U295 3823
Jeep Cherokee, Honda Fit

Re: crankshaft oil leak

Reply #15 –
Quote from: gam –
A small amount of oil can make a large mess .
That is a extremely true statement.  Having retired from hauling petroleum products for the last 20 years of career,  I can tell you that Joe knows exactly what he is talking about.  One spilled gallon of gasoline looks like at least 10 gallons and one gallon of diesel fuel looks like 30 gallons on the ground! 
1994 U225
build #4514

Re: crankshaft oil leak

Reply #16 –
Cummins now has a very much improved  crankshaft seal available for the 8.3 C Series.