Oil Leaks from 4.108 Timing Plate

[Rob H]

I am running a 4.108 1988 vintage. Thought I had a front timing cover leak. Resealed and went well except the leak appears to be from the front plate to block. I can see motor mounts must come off. Or is this possibly the pan gasket? Leak is 6oclock location to front of crank and druels down the front of the pan. Anybody else experience this or know if it is a common problem. Rest of engine is tight.

[GordMay]

Greetings and welcome aboard the CF, Rob H.

See the Workshop Manual
➥ http://www.marineryachts.com/perkins_manual.pdf

And the Parts Lists & Exploded Diagrams
➥ http://www.alberg37.org/Project%20DB...4-108parts.pdf

[cburger]

4.108's are legendary leakers. The front and rear main seals are typical leak points for these engines. I own a 1984 4.108 and when we serviced the motor the front and rear seal where replaced with super dumper synthetic seals that are supposed to eliminate leaking from this area, it remains to be seen. If the leak is not severe some choose to just live with the dripping and put an oil absorbant pad under the leak if possible.

http://www.foleyengines.com/FreeTech...4108.html.aspx

[Dynamo1181]

You have a lip seal on the crank behind the lower pully that is famous for leaking. Also the oil pan has a cork gasket section at the 6 oclock position that is a common leak point. Mine is currently leaking there as I bet yours is.
A

[DeepFrz]

http://www.cruisersforum.com/forums/...ube-52059.html

Some have said that the Walker Air Sep has stopped a lot of leaks in their 4-108s by reducing the pressure in the oil pan. Expensive but it cleans up the engine room.

[MikeTurner]

There have been several threads on 4.108 oil leaks of late, you may want to do a search to look at some of the other discussions. I'm chasing a leak(s) on mine now. It's like roof leaks in your house - where you see it isn't necessarily where it's coming from. My first step was to go around the engine looking for signs of leaks, I found one on the breather tube that comes out of the rocker cover and goes to the air cleaner - oil dripping down from a loose hose connection, traveling along the edge of the rocker back to the back where it's been pooling at the back of the rocker cover, and then slowly dripping down the rear of the engine. I also found quite a bit of oil at the low point of a hose that passes across the lower front of the engine, not sure yet where it's coming from but it's in the same area you describe. I've found several loose fittings around the engine that have worked loose due to low RPM vibration and tightened things up. Today I'm degreasing/cleaning so I can run the engine and look for new signs of leaks. I'll be watching this thread to see how it may relate to what I'm seeing on my engine.

[Dynamo1181]

Can someone explain how the Walker units works to reduce pressure? I have gone to the Walker site and have found little on the technology used to reduce the pressure vs the stock slobber tube on the perkins.
Thx
A

[Rob H]

Will be checking the pan gasket tomorrow. ( yes with a mirror ) Impossible to see other wise. It is in a 36' Watkins. For anyone chasing oil leaks if you are not already using it. Brake clean is the best product for drying anything oily. It makes fuel or oil bone dry! Just make sure you have plenty of ventilation and a rag or towel to absorb the run off. Truly amazing stuff.

[MikeTurner]

I found my oil leak - appears to be a pinhole in the timing cover behind the flywheel pulley. The entire side of the timing cover has suffered corrosion apparently due to water leaks from the water pump">raw water pump - and apparently the PO painted over it before we bought the boat. The corrorsion was concealed by paint until I started looking closely in chasing the leak. I'm looking for a replacement cover - anyone with any possible sources? Also, anyone with any suggestions for a repair to the existing cover? The leak is pretty significant so I don't think just trying to manage it with absorbant pads is realistic, it's probably leaking a tablespoon of oil every few minutes when running.

[Steve W]

JB Weld might work as a temp fix for the pinhole, if you can get to the area, clean and prep it well. Probably not effective for the entire side of the timing cover.

[GordMay]

Originally Posted by MikeTurner

... I'm looking for a replacement cover - anyone with any possible sources? ...

Perkins Distributor Locator
➥ Perkins Diesel Engines & Powerpart Parts: Find a Distributor

[cburger]

Originally Posted by MikeTurner

I found my oil leak - appears to be a pinhole in the timing cover behind the flywheel pulley. The entire side of the timing cover has suffered corrosion apparently due to water leaks from the raw water pump - and apparently the PO painted over it before we bought the boat. The corrorsion was concealed by paint until I started looking closely in chasing the leak. I'm looking for a replacement cover - anyone with any possible sources? Also, anyone with any suggestions for a repair to the existing cover? The leak is pretty significant so I don't think just trying to manage it with absorbant pads is realistic, it's probably leaking a tablespoon of oil every few minutes when running.

Often times Ebay has used 4.108 parts, the other possible source would be to call outfits like TAD and Foley that do a lot of rebuilds and repairs on these motors and see if they have a cover, amke sure to have you motor's serial number handy as they will require this to match covers.