Why does an air filter keep falling off my port engine?

[Deleted User YDKXO]

I have MAN D2848 engines in my boat. Just recently one of the two air filters on the port engine has been regularly falling off it's mounting, usually after a high speed run. Every time it happens I very carefully put it back on it's mounting and tweak up the clamp as tight as I can but it still keeps occurring

This doesn't seem to be caused by the clamp itself loosening off as I have to unscrew it to get the filter back on to it's mounting. So what could be causing this and what damage could be done to the engine running for an hour or two without an air filter?

 

[RobWales]

I have MAN D2848 engines in my boat. Just recently one of the two air filters on the port engine has been regularly falling off it's mounting, usually after a high speed run. Every time it happens I very carefully put it back on it's mounting and tweak up the clamp as tight as I can but it still keeps occurring

This doesn't seem to be caused by the clamp itself loosening off as I have to unscrew it to get the filter back on to it's mounting. So what could be causing this and what damage could be done to the engine running for an hour or two without an air filter?

Just a quck suggestion Mike, remove the one that is still on and check if the paint is still in place on the o/d of the flange?
If it is then maybe this is what the rubber of the filter is gripping against as opposed to the shiney o/d of the flange it keeps jumping off!

Just a thought....

 

[omega2]

Try roughing the mating faces up with a bit of emery cloth?

 

[pan]

Maybe a light film of oil on the rim you are attaching it to, try cleaning with a solvent. Presumably you have tried manually pulling it off after re-fitting?

 

[[2068]]

Could the clamp or the mating surface have become a bit distorted?
It's difficult to tell from the photo.
If it's not gripping evenly across the surface, that could be a problem.

 

[jfm]

Mike, I'm guessing of course, but do you think the engine alignment is due a check? Misalignment tends to cause low frequency high displacement vibration of the engine, which is just the thing to shake that filter off. Often on a boat as big as yours you don't feel the vibration thru seat of your pants as much as you might expect. Basically I'm saying go into the e/room underway and see if that engine is shaking a bit too much.
I don't think any harm is done running engine w/o filter for a few hours. The air is squeaky clean and the filters are there to deal with dusty/dirty environments.

 

[colhel]

can you swap filters with the starboard engine?

 

[Portofino]

If its any consolation last year I had it too ,also port Engine 2876 -straight 6 so only one .
I ended up after I recall ? The 2nd time buying another .Thats been ok .
Mind ful of £90 a pop or there abouts -you have just reminded me to check them next visit .

I would be careful sanding the metal coller -you don,t want fillings getting sucked in !

It's probably a duff batch the black plastic and clamp cos it's not a great fit and due to different coefficient of thermal expansion -when running at near full pelt comes loose and vibrates off .

I did as the next step if prob recurred ,which it hasn't think about using a piece of wire to tie it on -stop it from moving back .

Of course when it's time to change them agian -maybe back to Sq 1. . .?

 

[BruceK]

Vibration as said most likely.
Highly unlikely but worth a check. Is there any trace of soot anywhere inside the air filter? i.e. dodgy intake valve.

 

[jimmy_the_builder]

Obviously Mike it's because you haven't got a gyro...

 

[baylabayla3288]

Mike, I'm guessing of course, but do you think the engine alignment is due a check? Misalignment tends to cause low frequency high displacement vibration of the engine, which is just the thing to shake that filter off.

Does your Ferretti have remote V-drive transmissions? If yes, miss alignment of the prop shaft would not cause engine vibration unless very severe. As suggested try to swap the filters, it could be just a problem with the filter attachment.

 

[Deleted User YDKXO]

Mike, I'm guessing of course, but do you think the engine alignment is due a check?

Vibration as said most likely.

Does your Ferretti have remote V-drive transmissions? If yes, miss alignment of the prop shaft would not cause engine vibration unless very severe

Yup my boat has V drives and apparently the engine mounts are 'softer' as a result. My first thought was engine vibration but I've checked the engine visually at speed and I can't see any sign of undue vibration nor any difference with the s/b engine. Neither can I feel any undue vibration in the boat

If it is then maybe this is what the rubber of the filter is gripping against as opposed to the shiney o/d of the flange it keeps jumping off!

Try roughing the mating faces up with a bit of emery cloth?

Maybe a light film of oil on the rim you are attaching it to, try cleaning with a solvent. Presumably you have tried manually pulling it off after re-fitting?

Yup tried very hard to pull the filter off after I refitted it and couldn't budge so I'm not sure that this problem is due to the slippy mating surface. Also why wouldn't the same thing happen with the other 3 filters on the engines? I will clean the flange with solvent though just to make sure it isn't oily

It's probably a duff batch the black plastic and clamp cos it's not a great fit and due to different coefficient of thermal expansion -when running at near full pelt comes loose and vibrates off .

Yup I think you may have got it there as the problem has only occurred after I've worked the engines hard. I guess there must be differential expansion between the metal clamp holding the filter and the mounting flange. The filter isn't quite a square fit on to the flange anyway so there may also be a manufacturing fault with it. As you suggest I think I will change it for a new filter

Obviously Mike it's because you haven't got a gyro...

Yes Jimmy I have already added it to my extensive list of reasons which I will submit to the SWMBO as to why we need a gyro

 

[MapisM]

Yup my boat has V drives and apparently the engine mounts are 'softer' as a result. My first thought was engine vibration but I've checked the engine visually at speed and I can't see any sign of undue vibration nor any difference with the s/b engine. Neither can I feel any undue vibration in the boat

M, if you feel you can safely rule out vibrations, fine.

But does your boat have REMOTE V drives, which is what baylabala correctly asked?
IIRC, what you've got are integrated gearbox+V drive units, directly attached to the engines, which implies that the thrust (hence vibrations) is transmitted straight to the engines regardless of V drives.
In turn, this also means that the engine mounts should be "normal" rather than "softer", unless shafts are built in such way that the thrust is transferred to the hull, as with aquadrive or seatorque systems.
But (again, IIRC) what you've got are traditional shafts - with seals rather than stuffing boxes of course, but that's neither here nor there, in this context.

Just for the records, I'm assuming that by "remote V drive" baylabayla meant those setups where there's a gearbox-only attached to the engine, then a jackshaft connected to a V drive-only unit - and only the latter takes the engine thrust from the prop shaft.
A rather common setup in older Ferrettis, btw: 54, 175, 60, 62, 620, 165, 55, 57, 590 - all with jackshafts + BPM V drive-only units. And I'm sure I'm forgetting some others...

One last thought: it's a funny coincidence that not only the engine, but also the cylinder bank is the same where Andrea found a minor leak from the exhaust flange.
Did you mention him also the self-removing filter, or did that only happen after you left CF?
Regardless, that might strengthen the shaft-induced vibration theory of jfm, I reckon...

 

[henryf]

Keep things simple.

Fit that filter on the other engine and the stbd filter on your port engine. See if the fault follows the filter & clamp or stays with the engine.

Hopefully it follows the filter to eliminate more involved solutions.

Henry

 

[Deleted User YDKXO]

But does your boat have REMOTE V drives, which is what baylabala correctly asked?

Definitely have remote V drives as pic below shows

Having said that, of course I cannot dismiss the vibration theory. One thought that has occurred to me is this. The engines have about 940hrs on them and at 1000hrs, the MAN service schedule requires that the valve clearances are checked and adjusted. Could it be that the valve clearances are already out of adjustment on the port engine and are causing some vibration that I cannot see? Just a thought

One last thought: it's a funny coincidence that not only the engine, but also the cylinder bank is the same where Andrea found a minor leak from the exhaust flange.
Did you mention him also the self-removing filter, or did that only happen after you left CF?

That is a good point. No the self removing filter has only been happening since we left CF, in fact only since we left La Spezia, and as I say only when I work the engines hard ie 2000rpm+. I only do this for short periods obviously. Btw she still pulls 34kts if the tanks are not too full. Not bad for a fat old Italian mama, eh

 

[baylabayla3288]

M, if you feel you can safely rule out vibrations, fine.

But does your boat have REMOTE V drives, which is what baylabala correctly asked?
IIRC, what you've got are integrated gearbox+V drive units, directly attached to the engines, which implies that the thrust (hence vibrations) is transmitted straight to the engines regardless of V drives.
In turn, this also means that the engine mounts should be "normal" rather than "softer", unless shafts are built in such way that the thrust is transferred to the hull, as with aquadrive or seatorque systems.
But (again, IIRC) what you've got are traditional shafts - with seals rather than stuffing boxes of course, but that's neither here nor there, in this context.

Just for the records, I'm assuming that by "remote V drive" baylabayla meant those setups where there's a gearbox-only attached to the engine, then a jackshaft connected to a V drive-only unit - and only the latter takes the engine thrust from the prop shaft.
A rather common setup in older Ferrettis, btw: 54, 175, 60, 62, 620, 165, 55, 57, 590 - all with jackshafts + BPM V drive-only units. And I'm sure I'm forgetting some others...

correct MapisM, indeed I ment remote V drive where the thrust is taken up by a remotely mounted gear/v-drive unit.

 

[No Regrets]

Dab a couple of bits of silicone sealer on them just to prevent them from moving around. Easy to remove when you need to...

 

[MapisM]

Definitely have remote V drives as pic below shows

I read your post just before breakfast, so that was a good opportunity to eat a big humble pie portion...
Must have mixed up the fact that your setup is anyway different from the other Ferrettis I previously mentioned, in that your V drive unit integrates also the gearbox.
...unless my memory, yet again, does not serve me well!

Fwiw, I'm skeptic that valves adjustment can have anything to see with that, but I have zero experience of self-detaching filters! No problem at all to ring A and ask him if he ever saw anything like that, and also his view on valves clearance, if you wish.

Yep, 34 kts might well be the forum top f/b speed, I would guess...
Pretty impressive, considering that her beam is half way between a P67 and a Sq78...! :encouragement:

 

[jfm]

Yup, humble pie here too - as baylabayla said my theory is not applicable to remote V drives with jackshafts.

Valve clearances out of adjustment do of course create their own little mechanics and vibrations at the valve head as, say, the valve is struck harder and forced to accelerate faster, so getting them set right is important, but that sort of vibration is almost imperceptible to humans and I'd doubt it would make an air filter fly off.

Yup, swap the filters I guess, and see what happens. Intriguing! If you go into the e/room underway and shine a strobe light, you can see all sorts of vibrations - in slo-mo - that are invisible normally

I'm in Antibes for a 3 day weekend, flying tonight. Might see you around Deleted User- beer on your aft deck?! - if you're still there.

 

[Deleted User YDKXO]

Must have mixed up the fact that your setup is anyway different from the other Ferrettis I previously mentioned, in that your V drive unit integrates also the gearbox.
...unless my memory, yet again, does not serve me well!

Yup that is correct! It is a ZF combined V drive/gearbox and there is no gearbox on the back of the engine. I too am sceptical about the valve theory but I'm clutching at straws a bit here. I would be very grateful if you could mention it to A in passing if you happen to speak to him. Btw he still hasn't sent me his invoices for recent work. I give up on that!