Oil Leak On A Perkins Perama M35

[jenain]

I have a Perkins Perama M35 diesel engine in my yacht. I has a big oil leak , that seems to be comming from the rear of the block. The leak only happens when the engine is running. About 1000 hrs ago, there was a small leak from the rear crankshaft oil seal,so, today, I pulled the engine out, and changed the rear crankshaft oil seal again. The leak is still there! Does anyone have any suggestions?

[MMNETSEA]

Originally Posted by jenain' date='07 August 2010 - 12:53 PM

I have a Perkins Perama M35 diesel engine in my yacht. I has a big oil leak , that seems to be comming from the rear of the block. The leak only happens when the engine is running. About 1000 hrs ago, there was a small leak from the rear crankshaft oil seal,so, today, I pulled the engine out, and changed the rear crankshaft oil seal again. The leak is still there! Does anyone have any suggestions?

Hello Jenain

Noted that oil leak "seems to coming from the rear of the block" Need to know what type of seal :-

Is it a single spring-loaded seal fitted first on the output shaft? or is the seal in two separate halves ? I don't have a manual for this model. I assume you had to remove the sump pan from the engine, repace the seal/s AND replace the sump gasket.

Where are you based at the moment ?

Richard

[jenain]

Originally Posted by MMNETSEA' date='10 August 2010 - 05:30 AM

Hello Jenain

Noted that oil leak "seems to coming from the rear of the block" Need to know what type of seal :-

Is it a single spring-loaded seal fitted first on the output shaft? or is the seal in two separate halves ? I don't have a manual for this model. I assume you had to remove the sump pan from the engine, repace the seal/s AND replace the sump gasket.

Where are you based at the moment ?

Richard

Hi Richard,

Thanks for the reply.The seal is a single spring loaded lip seal, and it fits around the end of the crankshaft.It is held in position by a 3mm steel plate that fits between the engine block and the bell housing for the flywheel. It was not necessary to remove the sump, but I have checked that gasket, it is fine. The leak only occours when the engine is running,i.e. there is oil pressure and flow, and appears to originatesomewhere between the engine block and the bell housing. With the motor installed, I cannot see much, and when it is out in the galley, I cannot run it, as once the bell housing is off, there is no way to fit the starter motor! I am at Yacht Haven in Phuket.

Bill

[MMNETSEA]

Originally Posted by jenain' date='11 August 2010 - 05:11 AM

Hi Richard,

Thanks for the reply.The seal is a single spring loaded lip seal, and it fits around the end of the crankshaft.It is held in position by a 3mm steel plate that fits between the engine block and the bell housing for the flywheel. It was not necessary to remove the sump, but I have checked that gasket, it is fine. The leak only occours when the engine is running,i.e. there is oil pressure and flow, and appears to originatesomewhere between the engine block and the bell housing. With the motor installed, I cannot see much, and when it is out in the galley, I cannot run it, as once the bell housing is off, there is no way to fit the starter motor! I am at Yacht Haven in Phuket.

Bill

Hello Bill,

Thanks for the update, A couple of questions :- what holds the 3mm plate against the seal? Is it just held by the face of the bell housing?

Another test ;- what happens when the dip stick is removed while the engine is running ? Does oil come squirting out of the dip stick hole? It could be that only the bearing galleries are receiving pressurized lubricating oil -- while the rest including the output shaft end of the crankshaft get their oil from 'splash' lubrication. If the latter then it could still be the oil seal that is the problem ;- possibles = worn output area of the shaft; wrong size seal; seal wrong way round; 3mm plate not held tight against the seal; seal pushed too far into the sump ??????????

I am coming down to Phuket near the end of the month to complete the modification survey of another boat in the BL.

Richard

[Spike_dawg]

Nearly all leaks will look like they are coming from the back of the engine. This is due to the mounting.

Perama leaks...

The engine will spew great amounts of oil if the dipstick is not properly seated.

An oil filter leak will show up at the back right side of the engine.

Perama uses a block front plate onto which the raw water pump is attached and also a few other things. It tends to bend at the raw water pump. The oil runs along the block and drips off the back of the engine.

The valve cover has a rubber o-ring which may be unseated. It is re-useable.

Hope this helps

[jenain]

The mysterious oil leak problem is solved! The cause was an oil filter that did not compress the rubber sealing ring. The rim of the filter was in contact with the side of the engine block, before the rubber sealing ring was compressed. Simple to fix, but I had to take the engine out twice to find this! The first time I removed the engine, removed the flywheel, and found there was a little oil there. I replaced the rear crankshaft oil seal, thinking that this was where the leak occurred. The second time I removed the flywheel, there was not a trace of oil, so I started looking elsewhere for the leak. I never suspected the oil filter, but decided to change it anyhow, as this is easy to do when the engine is out, and rather less so when the engine is installed, due to the limited access. That’s when I discovered that the spin on filters, the old and the new, touched the engine block. On both filters, the central thread was also not aligned to the outer casing, when you screwed them onto a bolt, this was obvious. The local auto spare parts shop said that this was a manufacturing fault with that particular batch of filters from Fleetguard. (I had bought two of them in Thailand prior to sailing to Chagos). On checking my service records, I found that I had used the same Fleetguard filters previously without any problems.

Unfortunately, we cruisers often have to buy whatever filters, vee belts etc are available, without the luxury of choice. I have learned another hard lesson, and will now check all spin on filters before installing them. Hope this helps someone out there, and thank you to all who replied to my post.

[Lighthouse]

Thanks for the update. Happy all is well now.