Westerbeke 40 / Perkins 4-108 Leaking Oil

[svaletheia]

Hello everyone,

I have a Westerbeke 40 based on the Perkins 4-108 engine (there were 40s based on the 4-107 and 4-99 as well, apparently) which leaks oil while running under load from the following orfices:

1. Around the front timing cover, a slow drip that leaves a small trail down the engine front.
2. Around the crankshaft pulley (but I know why this is - the pulley adapter flange is grooved from a seal that sat way too long) - about 2-3 tablespoons of oil per 10 hours of operation combined with #1, not sure how much of either in total.
3. From somewhere in the rear of the engine between the engine and the transmission - I can see a sort of spray/drip pattern on the forward facing surface of the flywheel cover and on the case of the starter motor. This is about the same volume of oil leakage, maybe slightly more, than #1 and #2 put together.
4. Possibly from around the edges of the oil pan.

Also, a slightly related issue:

5. The oil SEEMS to get rather thin over use, although it does not increase in volume. It just seems... diluted? No evidence of oil cross contamination in the coolant and it does not seem that coolant is in the oil, either. Fuel in the oil?

Now, I looked at the price of a new timing cover gasket and it just about made me crap my pants. Also, I understand that to replace the rear main seal, which I am totally guessing is what is causing #3, I need to pull the engine and transmission apart, remove the flywheel and casing, and get to the rear of the engine - that part is also NOT CHEAP.

The questions I have for you all is:

A. Are these normal-ish places to see leaks from this engine?
B. How much of an absolute pain is it to replace the rear main seal and does it involve fully realigning the engine to the prop shaft (I have zero experience doing this and would need to hire someone to do it right the first time while I watch to learn).
C. What do you all do when you need to pull the timing cover off to avoid spending a heinous amount of money on that gasket?
D. Any comments and/or previous experience anyone wishes to shed on my current situation?

Thank you,

-- Daniel

[Jesse]

The locations you've listed are the usual suspects when oil is found in the bilge but don't tend to develop for quit a number of years. The timing cover seal is usualy the easiest to replace depending on ease of access,but I don't know of a cheap or substitute replacement for the gasket other than making your own and that is not easy and I've had little success with it. I don't know of a way to replace the front seal without removing the timing cover and re-installing it requires a special tool or a very deft touch to line up the water pump">raw water pump with its drive. The other two are nearly imposible to address with the engine in place and moving the engine even slightly will require realignment, but it realy isn't that difficult, it requires time patience and thought and a bit of instruction but it is do-able. Something you might consider if the engine is nearing time to rebuild and can live with oil absorbent pads in the bilge for awhile is to wait and do it at that time. Whatever you choose good luck with it.

[Dockhead]

Originally Posted by svaletheia

Hello everyone,

I have a Westerbeke 40 based on the Perkins 4-108 engine (there were 40s based on the 4-107 and 4-99 as well, apparently) which leaks oil while running under load from the following orfices:

1. Around the front timing cover, a slow drip that leaves a small trail down the engine front.
2. Around the crankshaft pulley (but I know why this is - the pulley adapter flange is grooved from a seal that sat way too long) - about 2-3 tablespoons of oil per 10 hours of operation combined with #1, not sure how much of either in total.
3. From somewhere in the rear of the engine between the engine and the transmission - I can see a sort of spray/drip pattern on the forward facing surface of the flywheel cover and on the case of the starter motor. This is about the same volume of oil leakage, maybe slightly more, than #1 and #2 put together.
4. Possibly from around the edges of the oil pan.

Also, a slightly related issue:

5. The oil SEEMS to get rather thin over use, although it does not increase in volume. It just seems... diluted? No evidence of oil cross contamination in the coolant and it does not seem that coolant is in the oil, either. Fuel in the oil?

Now, I looked at the price of a new timing cover gasket and it just about made me crap my pants. Also, I understand that to replace the rear main seal, which I am totally guessing is what is causing #3, I need to pull the engine and transmission apart, remove the flywheel and casing, and get to the rear of the engine - that part is also NOT CHEAP.

The questions I have for you all is:

A. Are these normal-ish places to see leaks from this engine?
B. How much of an absolute pain is it to replace the rear main seal and does it involve fully realigning the engine to the prop shaft (I have zero experience doing this and would need to hire someone to do it right the first time while I watch to learn).
C. What do you all do when you need to pull the timing cover off to avoid spending a heinous amount of money on that gasket?
D. Any comments and/or previous experience anyone wishes to shed on my current situation?

Thank you,

-- Daniel

I have about ten years experience with this excellent, bullet-proof engine.

I think what you would need to worry about is if the engine does not leak from one of those places. That would be a sign of trouble (probably, low oil level).

I would advise you against doing anything against the oil leaks, which are absolutely characteristic. It is, for one thing, futile. You can change all of those gaskets and seals and you will find that the engine leaks all the same. Just keep an eye on the oil level and change the oil regularly. We used to put Pampers under the engine in the engine compartment and change them from time to time (dispose of properly). Works a treat. Enjoy.

I have no idea how many hours we put on ours. The hour meter was broken at 4,000 hours when we bought the boat, and was still going strong ten years later after very hard use, including hundreds or thousands of hours of running the engine at idle to charge batteries at anchor (a big no-no), the rest of the time just putt-putt-putting along at 1900 rpm. On all kinds of iffy fuel, without any special filtration. Absolutely no repairs during that period, whatsover. Just add oil and diesel fuel, and change a filter or impeller from time to time. Fantastic engine.

[rustyrusty]

I am looking at a leopard 38 with two westerbeke 40s done 2200 hrs I went to a local charter company I spoke to a machanic that told me they were a load of junk and he just pulled 2 out and replaced them with Yannmas he said they had problems with wireing vibrating off the motors were vibrating the boat to bits he said it is a different boat now with the new motors what would you say. I dont want to buy myself a problem. But I see there is a lot of them around no so many in Australia.

[svaletheia]

rustyrusty: welcome to the forum! Its best to start your question as a separate topic, but I'll give you a short answer here.

Vibration isn't a result of the engine but rather a bad installation. Westerbekes have a long and extremely solid reputation for being excellent motors.

Rather than shift this thread's topic to that, however, go ahead and do a search in this forum for people discussing the reliability of various diesel engines and you will get a lot of good info. If you still don't find what you are looking for, then start a new topic with your question in it.

[DeepFrz]

svaletheia, you might want to read this thread.

http://www.cruisersforum.com/forums/...-a-6807-2.html

[daedaluscan]

Lots of good W40 and W50 Info here.

Tartan37.com • View forum - Engine Maintenance

A recent thread about changing rear seal too here for example:

Tartan37.com • View topic - Rear oil seal leak

enjoy, Charlie

[digi]

The five stars nailed it.....Its a leaker; follow up with regular diaper use and it will become part of your estate. Mine is a 1978 with regular uninterupted use on a 43 ft ketch.

[Dynamo1181]

Daniel,
I suggest that you snug up the bolts on the timing cover and the oil pan. I also pulled the bolts off the inspection plates on the side of the engine and used a gasket sealer like permitex to seal the threads/bolt heads. This process might stop 80% of the leaks. The front seal is easily addressed and the rear less easy but doable as detailed. I am going to say that short of replacing the two gaskets that you may be down to leaking a couple tblespoons of oil per 100 hrs. I use a kitty litter plastic box under my engine and its catches 100% of the drips. But find whatever will fit and use a couple blue shop paper towels in the pan/box and you will have it under control. I have 6800 hrs on my 4108 and still love the guy. Others i know of easily were running at 12,000 hrs without a rebuild. My engine time is the hardest on a diesel which is charging batteries and running a frig compressor. I use one qt of oil between changes and leak less than 1/4 cup.
If you do replace that rear seal, DO NOT CUT the excess...use the whole seal!
Alan

[John Galt]

My 4-108 films over the bilge water with a fine sheet on a regular basis. It's a Perkins!
Having said that, I never start it without checking the oil level.
I heard a man say once that the Brittish never made vacuum cleaners because they couldn't find a way to make them leak oil!

[1corinthian]

I have a Perkins 4-108 in a Beneteau Evasion ketch and after ten years of ownership have learne to live and love this engine . For me the largest source of oil leakage has been the main bearing oil seal which leaks into the bell housing from where the flywheel , when sufficient has collected , sprays it out through the starter aperture. I have overcome this by drilling and tapping a nipple into the bottom of the bellhousing whence the oil dains via a plastic tube into a plastic milk container .It is surprising how little oil actually is collected but it has made a huge contribution to engine bay cleanliness for virtually no cost .

[brooksie]

It doesn't sound like you're leaking too badly. I have the same engine and the same 'problem' and have chosen to ignore it on account of bad access. I figure if i have to top it up every now and then it will probably be good for the engine as it'll keep the acidity down and the concentrations of oil additives up between oil changes!

I like the pampers idea dockhead and will be trying it out!

[Cheechako]

I understand some people have had leak issues with the 4-108. I guess I was lucky, my 4-108 had no leaks when I got it and had no leaks 4 years later when I sold the boat. If your engine is good, it might be a good thing to remove it, and reseal the whole thing.... paying very close attention to the sealing surfaces where the leaks are occurring, as well as using Permatex or similar product on gaskets like the front cover...

Another topic: Has anyone heard of a westerbeke 4-230? The engine I saw appears to look a lot like a 4-108 as far as the rocker cover etc. But different heat exchanger....

[MikeTurner]

Originally Posted by Cheechako

paying very close attention to the sealing surfaces where the leaks are occurring, as well as using Permatex or similar product on gaskets like the front cover...

This is now an older thread but perhaps good for future research on the topic so I'll add my current experience. I'm in the middle of repairing similar leaks on my 4.108 right now. In my case, the raw water pump shaft seal apparently failed some time ago and the pump has been weeping, with raw water running down the side of the timing cover. The PO had painted over rust in this area; I think more raw water got trapped between the paint and the surface of the cover. Short story: 12-14 pinhole rust leaks in the timing cover. I've fitted a new timing cover with new crankshaft seal; will be finishing up the job over the next couple of days. The instructions that came with my gasket set said not to use any sealant like Permatex - but I used a few dots of Permatex to hold the timing cover gasket in place while I fitted the new cover. The PO, incidently, had had the timing cover off at some point and used silicone to make a gasket, didn't have a gasket per se.

Finally, when removing the timing cover and raw water pump there's a lot of info out there about the special tool needed to align the pump adaptor plate to the timing gear that drives the pump. I rented one of these tools, only to find I didn't need it. The 4.108 was fitted with two different raw water pumps, Jabsco and Sherwood. The Jabsco pump uses the adaptor plate and requires the tool for alignment. The Sherwood pump doesn't have the adaptor plate, the pump flange is the same size as the adaptor; and the special tool cannot be used. Alignment is by cranking the engine with the pump lightly fitted, to allow it to center on the shaft; and then tightening down.