Failure Analysis: Did a Baldwin PA2721 Filter Failure Kill our 8V71 Engine?

[technomadia]

I just posted about our experiences digging into the air filter failure that accompanied our engine overheat this summer.

  Link: http://www.technomadia.com/2013/10/failure-analysis-did-a-baldwin-pa2721-filter-kill-our-8v71-engine/

We can't know for certain that the Baldwin filter was at fault, but overall we've lost all faith in Baldwin and will not be letting a Baldwin product near our bus ever again.

I know a lot of people here were waiting for an update on our final analysis on what killed our engine. This is it - sharing all the details that we have.

Cheers,

   - Chris

[Lin]

Thanks for the follow up.  When you guys went through your ordeal, I decided to change my air filter as a preventative measure.  Our configuration is the same as yours with the air flowing from the inside to the outside of the filter, although judging from your Wix number, we have a different canister.  In any case, both the NAPA filter that we removed and the Donaldson that we replaced it with have substantial support around the outside of the filter.  The NAPA had a steel mesh and the Donaldson had a perforated metallic sheet.  I would really question whether a filter that does not have such protection could really be honestly specified for two way flow.

As far as the filter failing due to moisture, it would seem to me that driving in a serious rain or snow storm would be likely to bring a lot of moisture into the filter.

[lostagain]

So your filter got wet, failed and debris got sucked into the engine. Evidently water got sucked in from the air intake during a rain storm while driving. I can't imagine the Florida dampness would weaken a filter to the point of failure in such a short time. Does your bus have some sort of baffle upstream of the filter to separate the water out of the air? My 5C did, until I built a custom intake that draws from high up on the side of the bus to ingest less dust on gravel roads. But I drill two 1/8" holes, one on each end of the filter canister (a Fleetguard, Eco type that flows from outside to inside) for water to drain out. I kind of doubt that it actually drains until the engine is shut down. I replace the filter once a year. I have cut up an old one, and was impressed at how sturdy it is, with mesh and hot melt beads inside and out.

JC

[technomadia]

Great idea on a baffling system, we'll have to see what is possible in our configuration.

However, in the 10 months that we drove on this filter - I can only recall it raining of any significance once. It lasted about 20 minutes, and wasn't that strong of a rain. Any other rain we might have drove in was light and quick passing. And certainly we encountered no snow in Florida

In general, if the forecast is for rain - we stay put until it clears up. There's rarely anyplace we need to be that badly that we don't have the flexibility to wait for clearer skies.

- Cherie

[TomC]

Most air intakes will have some sort of moisture evacuation system. Usually a flat rubber looking thing commonly referred to as a kazoo. This will eliminate any water that is sucked into the system before it even reaches the air cleaner. Highly recommend you go with Donaldson-they make the Detroit filters also. Good Luck, TomC

[belfert]

Dina puts a Donaldson air/water separator in the intake before the filter.  This should keep most of the water out of the filter.  I still get some moisture into my filter.  I go out to the Blackrock playa every year with the bus.  The filter minder never tripped, but after a few years I pulled the filter and it had a thin layer of mud inside it.  The playa dust probably combined with high humidity during Minnesota summers turned into mud.  I should probably plan on replacing the filter again next summer.

Dina has the air intake up at the roof line.  One problem with the design is there is no mesh over the intake and birds tend to nest inside and block the intake.  When I got my bus the intake was partially blocked by a nest.  I was able to make a temporary fix to bypass the nest to get me home.  Once home I got the nest out and covered the opening with mesh.

[luvrbus]

The ECO filter does not use a vaculator as Tom referred to as a "kazoo" never heard that before the ECO system has small holes to drain that is why they need to be installed level in both directions 

High humidity will kill a filter it doesn't have to be rain or snow,Baldwin couldn't be that bad that is only filter I ever saw at Swift Transportation  or Arrow Stage Lines in Phoenix 

I have never used the ECO style from Baldwin but have used plenty of their fuel,oil and air filters over the years in applications from heavy equipment to cars 

[lostagain]

Clifford, do you think those little holes at the bottom of the Eco filters actually drain water while running? I am thinking that air would be sucked in through them, and that water would not drain until after shut down. So it would not help for as long as you are driving in a downpour, which could be hours...

And even with a water separator, wouldn't a fine mist of moisture be continuously drawn into the filter? That would be worst than sitting in a wet climate like Florida.

99.9% of air filters don't seem to be adversely affected by that in a one year period or 4000 miles. I have taken wet air filters out, and didn't think they were at imminent risk of failure...

So maybe Chris and Cherrie you were unlucky and picked up a lemon filter? Or something else got into it, like starting fluid?

JC

[Iceni John]

About two years ago I noticed that my Racor Eco-BC filter had several small splits in the inside of the material, probably due to old age and possibly also from some rain damage.   I not only replaced it (Racor made me a brand-new filter to order, so I know it hadn't sat on a shelf deteriorating before I got it), but I also reworked my intake.   I extended the 7" inlet pipe higher to reduce the amount of rain that could get sucked in, and I made a water trap inside the intake housing to safely drain away any rain that did get inside.   The new filter also has a rubber drain valve in its base, something the old filter didn't have.   Most importantly, I made the intake cover removable in a few seconds without tools, so now I can easily see down inside the filter to check that everything's OK.   My Farr Filter Minder is still connected, but I don't trust it to tell me if the filter needs to be changed  -  if the filter's split and letting air through the gaps it won't help you.   A few months ago I also installed a turbo boost gauge  -  if it begins to read less than normal I'll know I have a problem somewhere in the intake system.   After my scare with the old filter I now check the inside of the air filter every few months.

Chris, could you arrange it so the inside of your filter is easily visible for inspection?

John   

[technomadia]

Does your bus have some sort of baffle upstream of the filter to separate the water out of the air?

Our bus draws in air from the passenger side, midway up.  There is an intake screen and a large multi-baffle chamber before the air filter, making the direct ingestion of water an essential impossibility.

I have checked inside the baffle chamber and it is clean and dry and not obstructed.

  - Chris

[technomadia]

Chris, could you arrange it so the inside of your filter is easily visible for inspection?

Unfortunately - not easily.  Not unless we cut a plexiglass window into the filter canister anyway. And since the canister is part of the filter, I am pretty sure that would be considered a warranty violation....  ;-)

Our filter is mounted up over the engine in a location that is actually really difficult to get at - making quick checks impractical.

We initially added the Filter Minder just to give us some extra piece of mind because the air filter is so hard to get at for a quick look.

   - Chris

[luvrbus]

Water gets in the GM filters from somewhere every oil bath filters I ever serviced  on a GM had water in them even here in the desert a air intake design for oil bath filters could be their problem who knows for sure 

JC I have tried to get the ECO to suck water in the drain hole must be the design I had no luck

[lostagain]

John, how did you make your water trap in your air intake?

JC

[Iceni John]

John, how did you make your water trap in your air intake?

JC

My engine air intake is about 7 feet above the ground, behind a louvered grill that is behind the last window on the right side.   The 7" intake pipe for the air filter itself is vertical, set back a few inches from the louvers, and in the space between the pipe and the louver I put a small plastic tray with a length of tube attached that drains away any rain water that blows in through the louvers.   Another reason I did this was because I moved my DDEC fuses to a location directly under the intake housing, and rain was getting in and dripping down on them  -  not good!   Now, if any water gets in, either it will harmlessly drip out the drain tube, or if it gets sucked into the filter the rubber drain valve on the bottom should (I hope) let it escape before it gets drawn into the engine.   Either way, the pleated filter element should never get significantly wet.   I think this was why my old filter began to split internally, but fortunately the splits did not go all the way through the material  -  there seems to be more than one layer of material in the Racor filters, so the outer layer(s) still remained intact.

The fiberglass interior cover for the entire air intake was originally screwed, glued and caulked in place, obviously never meant by Crown to be ever removed;  I reattached it with two stainless pins and some aluminum channel to make it easily detachable, and when it's removed I can easily peer down inside the air filter itself, sort of like a doctor telling you to say AAAAARR when he looks in your throat.

John  

[TedsBUSted]

IMHO - From this armchair, it doesn't look like the engine "digested" enough filter element to cause an immediate catastrophic failure.

I'd guess too, despite the shredded element, that the air intake wasn't restricted when climbing blow-up hill. Mostly because symptoms of a "gagged" engine were not reported.

I'd  guess that the element was "sucked out" before blow-up day, and so the engine had been breathing unfiltered air for some time; not good, but not cause for immediate catastrophic failure.

I didn't follow along every detail, but I don't recall reading about the "last chance" screen at the blower inlet being littered with filter element. Was it?  If this was a recent and quick element failure, I would think that there would have been "confetti" galore present.

It's my personal opinion that the filter's sizing is pushing limits and that a step up in filter size would probably have prevented the blow-out. Although it's (barely) within CFM application spec, to me, it looks like things  stacked up against the marginally sized filter.  I wonder too if an over-speed -at some time- could have pushed flow up just enough to be able to suck out  the border line element?

Ted