Water in Crank Case Filter

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Water in Crank Case Filter

August 03, 2013, 06:47:56 pm

How did water get in the crankcase filter?
On our last trip to NAC, while driving on I10 in a heavy rain storm, the Stop Engine light came on.... Cummins ISL9, 450 hp in our 2012 Nimbus. The Silverleaf error code indicated high crankcase pressure. So did the Cummins tech's laptop. They found water in the crankcase filter which sits on top of the engine under a cover. Replaced filter. Fixed. Best I can do. I'm not a tech but I now carry a spare filter.
The techs said they have not seen this problem before and it could have been condensation in gasses, etc..
FOT said they have not seen this problem either but hinted the air intake, high on left rear, might have sucked in water?
Any ideas would be helpful.

Re: Water in Crank Case Filter

Reply #1 – August 03, 2013, 07:01:59 pm

Rear Air Deflector

Well wouldn't it be funny if my little deflector I mentioned a while back was the snswer to this problem?
I designed and installed this plate for exactly that reason and I had a really wet air filter while driving thru a snow/rain storm from Yuma to San Diego. The water totally soaked it as it was sucking rain etc in by the cupfull, and when I stopped for the night I could not believe how wet it was. Reason for stopping was engine was running like s--t with no power etc.
It did not take me long to figure the reason so once home I put it on. No more troubles and it keeps the crap out and rear camera clean even in rain. I bet most of you when opening up that air filter can find a lot of debris in there too. Not me!!
John H

Re: Water in Crank Case Filter

Reply #2 – August 04, 2013, 07:36:57 am

John, thanks.
Interesting. Neither the Cummins tech nor the FOT tech either checked for a wet air filter. Our air intake is high up on the top rear driver's side curved corner close to the roof.
Don't need this to happen again in rain.
Anyone else?

Re: Water in Crank Case Filter

Reply #3 – August 04, 2013, 08:25:53 am

You ABSOLUTELY need to have the air filter element checked. Water breaks them down. If there is any sign of water damage, replace it.

But, the primary cause of moisture/water in the crankcase ventilation filter is starting the engine and then shutting it off before the OIL, not just coolant is up to temperature.

So, do you ever start the engine, but not drive 25+ highway miles. If so, THIS is likely the cause of the moisture.

Cummins, Caterpillar, etc all say the same thing-- if you can't drive 25+ highway miles, don't start the engine.

Brett

Re: Water in Crank Case Filter

Reply #4 – August 04, 2013, 09:44:37 am

Thank you Bret.
Great advise which makes sense given some history. The coach was a FOT "leftover" with 4K miles when we bought it last August. It had likely been on FOT's lot for several months. The problem happened this April.
After the problem, we had FOT replace all filters/oil, etc., including the air filter but I did not see the old filter.
Never had this problem with 15 years of SOB's which I always drove for an hour on the highway every 3 weeks when in storage. I also do this with our new baby, build 6557.
Doug

Re: Water in Crank Case Filter

Reply #5 – August 04, 2013, 09:52:57 am

Doug,

Given the history, quite likely it did a lot of start engine and idle or drive short distance and stop. That would sure account for excess moisture in the crankcase filter. I would pull it in another 6 months or so just to verify, but suspect this is an issue in the past.

Brett

Re: Water in Crank Case Filter

Reply #6 – August 04, 2013, 10:14:45 am

Quote from: dougself – August 03, 2013, 06:47:56 pm

FOT said they have not seen this problem either but hinted the air intake, high on left rear, might have sucked in water?

Doug,

Since there aren't a lot of 2012 Nimbus coach owners on the board, I copied some photos of (what I think is) yours from FOT's archived coaches site and highlighted the air intake in these photos. Earlier coaches do not have this design so it might not be familiar.

(because of my "processing", the photos aren't the greatest resolution. Folks will want to click on the image and then the "expando-box" icon at the top of the image to get the best-available view of the intake)

Michelle

Re: Water in Crank Case Filter

Reply #7 – August 04, 2013, 11:12:14 am

Y'all are amazing folks. Thanks for your help.
I'll check the air filter next time we're in heavy rain and in a few months. And never do a quick engine turn on/off.
Michelle, that is our coach. Should I climb up there and put those stickers on ... re-labeled "air only"?
What about one of those bug/air deflector thingies you put on car/truck windows to direct water away ?
Has anyone with a side air intake had problems with water being sucked in?
Doug

Re: Water in Crank Case Filter

Reply #8 – August 04, 2013, 11:30:22 am

Doug, if that was my coach I would not wait to put something up to deflect rain etc away. That to me is a stupid place to put an intake without protection, sorry. It needs covering at the leading edge and the top.
As explained before I had a loss of power/rough running and checked the filter, it was soaking, so let it dry overnight under coach(we were in S California side road for night so no parts shops close.)
I decided then that I needed something up there.
After fitting it we have done close to 20k miles and my filter is (checked it 6months ago) a light grey colour with no dust or junk in can so it is doing what I wanted it to do.
When I was at FOT 18 months ago I showed it to one of the service guys and he said that when they replace filters there is usually a big pile of "stuff" in the can as well as filter!! This also extends the life of filter-saving a few dollars.The added benefit is keeping the camera clear in rain for a longer period.
This is a project for Rance to form a nice moulded unit. I would make my own but of course would need a complete pattern of radius and sizes.
Dave thanks for the nice comment.
John H

Re: Water in Crank Case Filter

Reply #9 – August 04, 2013, 11:35:09 am

Water in the crankcase is usually caused by trips to the grocery store, prolonged idling, other short trips where both the water and oil temperature do not reach a high enough temperature for a long enough time. Until the engine block temperature along with the oil temperature reach higher than 180 degrees, the "blow by", air leaking past the piston rings will lose it's moisture as it makes contact with the cooler boundary layer next to the cylinder walls. As the moisture settles into the bottom of the crankcase, a small amount is absorbed into the oil but the rest remains in little droplets containing acids and other contamination. The higher the humidity, the more moisture will condense. With oil temperatures less than the mid-180 degree mark, the oil will not evaporate and may actually increase in concentration with continued driving practices. The breather cap is cooler than the engine interior so moisture passing through the cap will condense and form the nasty gray sludge seen there.

To avoid this, the engine coolant thermostat should be 180 degrees and the engine should be run at a high enough load so the oil will also exceed 180 degrees for a long enough period for the moisture to evaporate and pass out of the engine.

Owner removal of coolant thermostats in the attempt to achieve greater cooling is a contributing factor in crankcase sludge buildup.

Pierce

Re: Water in Crank Case Filter

Reply #10 – August 04, 2013, 12:09:28 pm

quote"air leaking past the piston rings will lose it's moisture as it makes contact with the cooler boundary layer next to the cylinder walls. Pierce

If the air going in to system is saturated by excess water in air filter then it gets into a kind of "overload" so if you deflect water away from air intake then less moisture means less removal by engine heat?
You comment seems to agree with my idea.
John H

Re: Water in Crank Case Filter

Reply #11 – August 04, 2013, 01:00:11 pm

Quote from: John Haygarth – August 04, 2013, 12:09:28 pm

quote"air leaking past the piston rings will lose it's moisture as it makes contact with the cooler boundary layer next to the cylinder walls. Pierce

If the air going in to system is saturated by excess water in air filter then it gets into a kind of "overload" so if you deflect water away from air intake then less moisture means less removal by engine heat?
You comment seems to agree with my idea.
John H

It would make sense that a diesel engine (or gas) engine with a southwest home base would see much less crankcase moisture than a high humidity area like the gulf coast. Winter would also be worse as it would take longer for the engine to come up to temperature and drawing air from a wet source as described above could initially cause increased condensation. But if thermostats and engine controls are operating correctly, it should evaporate rapidly once underway.

An air intake close to the rear wheels will pick up a lot of moisture from wet roads as well as a lot of dirt the rest of the year. Important on a short run to the grocery store. On a longer trip with normal operating temperature as stated above, the engine's internal temperature should not allow any moisture to condense and collect anywhere in the crankcase. Quickly reaching operating temperatures also insures that designed engine clearances are achieved and things like cylinder walls are parallel from top to bottom resulting in less piston ring flexing and ring land wear as the rings don't have to make up the difference from the larger diameter at the bottom to a "choke" at the top.

Water is used in programs to reduce NOx in diesel engines by injecting it into the combustion chamber. See a short explanation at: Diesel Truck Engine NOx Control Using Water Injection Study .

I start up with only enough time to get air pressure before driving when cold. I don't start thrashing the engine until temps have stabilized but then don't hesitate to "petal to metal" as the need arises. Even with lots of water vapor ingested from the behind the rear tire air intake, there has never been any indication of moisture buildup anywhere. While raining, the water really comes off the tires and the air cleaner is frequently very damp.

Rust or visible moisture/foam at the top of the dipstick is a good indicator of insufficient time at designed operating temperature. Modern oils have additives to neutralize small amounts of crankcase pollutants but a continued buildup can cause accelerated wear.

Pierce

Re: Water in Crank Case Filter

Reply #12 – August 04, 2013, 02:10:43 pm

I remember in my 93 GV the air filter was behind the drivers side rear wheels so it would get wet easily, but on the 2000 (like many other years they are basically inside the engine compartment so do not get this "throw up" from wheels. I think your air intake is by the side venting "mine was" and I had a very small deflector on that position too. It was never as wet as this one got with the back roof intake, and I never had any crap in container either.
Where is your intake??
John

Re: Water in Crank Case Filter

Reply #13 – August 04, 2013, 05:42:16 pm

Thanks again everyone for your clear explanations and advice. I wish I'd checked the air filter for water after the problem occurred. If it had happened on a clear day it would be easier to eliminate the air intake question.
I'll talk to FOT about the air deflector idea and see what they say. I hate to mess up the design. I'd like to think that if the air intake location was a problem on newer coaches FOT would use a different design. Some SOBs also have intakes in the same location.
Still beats bedbugs.

Re: Water in Crank Case Filter

Reply #14 – August 04, 2013, 07:04:13 pm

Quick check of a couple of coach pics and it looks like the side air intake design started in 2005. I saw a couple of 04's that did not have it but my 05 does. I've driven thru some rainstorms that I would have preferred not to and have had no issues.

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Water in Crank Case Filter

August 03, 2013, 06:47:56 pm

Re: Water in Crank Case Filter

Reply #1 – August 03, 2013, 07:01:59 pm

Re: Water in Crank Case Filter

Reply #2 – August 04, 2013, 07:36:57 am

Re: Water in Crank Case Filter

Reply #3 – August 04, 2013, 08:25:53 am

Re: Water in Crank Case Filter

Reply #4 – August 04, 2013, 09:44:37 am

Re: Water in Crank Case Filter

Reply #5 – August 04, 2013, 09:52:57 am

Re: Water in Crank Case Filter

Reply #6 – August 04, 2013, 10:14:45 am

Re: Water in Crank Case Filter

Reply #7 – August 04, 2013, 11:12:14 am

Re: Water in Crank Case Filter

Reply #8 – August 04, 2013, 11:30:22 am

Re: Water in Crank Case Filter

Reply #9 – August 04, 2013, 11:35:09 am

Re: Water in Crank Case Filter

Reply #10 – August 04, 2013, 12:09:28 pm

Re: Water in Crank Case Filter

Reply #11 – August 04, 2013, 01:00:11 pm

Re: Water in Crank Case Filter

Reply #12 – August 04, 2013, 02:10:43 pm

Re: Water in Crank Case Filter

Reply #13 – August 04, 2013, 05:42:16 pm

Re: Water in Crank Case Filter

Reply #14 – August 04, 2013, 07:04:13 pm

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