Compression Chk & Water in Oil

[Hoodsail]

Had a 1978 Bristol 35.5 surveyed for purchase. Westerbeke 30hp diesel ran well during sea trial, no overheating, but engine oil was grey. Analysis came back positive for coolant & hi sodium - confirming fresh and raw water in the oil. Compression test for all 3 cylinders was consistent at 450-475 PSI. Question - does the good compression test results rule out a blown head gasket?..What other sources for water besides oil cooler? Seller noted that oil was changed prior to laying up for last winter. boat has not been used since except for motoring from mooring to yard for short-haul. Negotiating with seller regarding next steps. Solid boat otherwise. thanks, dave

[Glenn.Brooks]

Is the boat in an area where the winters freeze up?? If so, likely the boat has a cracked head. Although running the engine with no coolant can also crack the head- but freezing the coolant certainly will, if the freeze is deep enough...

Cracked head would result in coolant- whatever is running through the engine block- being injected into the oil. Gasket not necessarily bad, but a cracked head would certainly leak into the oil.

Is sea water mixed in the coolant? Maybe your heat exchanger is leaking raw water into the antifreeze. Although this would show up almost immediately, so no real help on the last part.

Best to have a marine mechanic survey the engine, if you think you really want the boat.


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[CptLawrence]

The consistent compression is good news, oil in the coolant usually means a leaky heat exchanger. A westerbeke site might get more specific info for you if an expert does not help on this one. Did the smoke persist after the engine warmed?

[MarkSF]

Nice boat! I have the 31.1, but I have admired the 35.5 for a while. Quite possibly the perfect cruiser/racer.

At the risk of seeming slightly pedantic, but precision here is important, the engine you have should be a Universal M30 or 5424, which is based on the Kubota D1101 block. I have the same engine. This is a completely different beast from a Westerbeke W30, which is a 4 cylinder based on a Perkins (I think). To add to the potential confusion, Westerbeke took over Universal.

Anyway, at the age of that engine, there are several common failures : the jacketed exhaust manifold (which I think could concievably allow both salt and fresh water in), the heat exchanger (which could let salt water into the coolant), and also the raw water pump. If the bearing seals on that fail, water drips down the shaft directly into the crankcase. If you lived a good, honest life so far, that might be the only problem.

Here is the bad news : that engine is virtually at the end of its life. Not so much because of wear, but because of marinisation parts availability (the Kubota block is easy to get parts for). The exhaust manifold is completely unavailable, as far as I know.

So while you might be able to patch it up, the best plan would be to get a discount that covers most of the cost of a repower, and drop a Beta Marine in.

On the bright side, this might be a chance to get a great boat with a new engine at a decent price.

[Stu Jackson]

Originally Posted by CptLawrence

...oil in the coolant usually means a leaky heat exchanger.

Sorry, doesn't work that way.

While the boat may be to your liking, i agree that the engine may be toast, although it could be as simple as a weeping raw water pump. Check it out carefully.

If you choose, you could consider repowering with a new Beta, nothing but rave reviews all over the boating internet.

Good luck.

[MarkSF]

Originally Posted by CptLawrence

oil in the coolant usually means a leaky heat exchanger

On a car engine, yes. On a small marine diesel, no. Never heard of one with an oil to coolant heat exchanger.

[Hoodsail]

Many thanks for the information. I am having a marine diesel mechanic (Hansen Marine, Marblehead, MA) inspect the engine, run her, and re-check oil that was just changed by seller after my survey. This is Dieter Empacher's boat so a number of features I have not seen on other 35.5 (eg 2 pilot berths) and per the surveyor she has a Westerbeke 4 cylinder (not 3 as I earlier noted) 30. This will be confirmed by mechanic's inspection.
No smoke during warm up or sea trial while under load.
Stay tuned..
Dave

[lifeofreilly57]

You can have head gasket issues and still have good compression, there are different passages through the block to the head, some carrying pressurized oil to the head, some allowing the oil to drain back down, and others carrying coolant through the head to cool it, especially around the exhaust valves.
If only part of the head gasket is compromised you can get the issue of coolant int he oil. Still doesn't explain the salt water though.
You may have more than one problem, leaking raw water pump and head gasket?
You took the best route by having a competent marine mechanic look at it.
Maybe a relatively cheap fix, all things being relative, or maybe the engine is junk.
Since your looking to purchase assume the worst case scenario.

[Glenn.Brooks]

Following up with your head gasket or cracked head idea, it's possible your two problems are directly related, with the mixed sea water in the coolant causing the oil in water contamination. here is a scenario to potentially check out with your mechanic.

1) I assume the heat exchanger is old, perhaps original, and is now leaking raw water into your coolant (fresh water system). They all fail eventually if old enuf...and tend to do this.

2) if it is the heat exchanger, sea water will typically inject into the coolant. This will dilute your coolant, making it less able to withstand freezing winter temperatures during winter layup- possibly cracking your head, which leads to salt water and coolant mixing with your engine oil through the cracks in the head and journals leading to the lubricated surfaces, during operation in the spring. Marblehead Maine temps got down to -6 F last January, so certainly cold enough to freeze diluted coolant in the engine, if it wasn't drained, cracking the head.

3) alternatively, upon start up this spring, the diluted coolant overheated the engine, causing the head to warp and blow out part of the head gasket, same result as #2 above.

4). Salt water in the engine oil, regardless of cause, is a bad thing, as the salt starts to corrode and score (sp??) the journals, bearing surfaces and engine parts, etc. So, at a minimum, and regardless of the head/headgasket issue, flush the engine repeatedly with fresh oil changes- up to five or six times soon as you reach operating temperatures - to eliminate any salt residue from internal engine surfaces. This will help save the engine from damage caused by salt water ingestion.

An easy way to check for a cracked head or head gasket problem is to run the engine up to normal operating temps with the 'radiator' cap off the expansion tank. If you see air bubbles roiling the surface of the coolant, or coolant starts to smoke and boil, you know you are getting superheated coolant out of the defect in the head. Combustion in the cylinder blows heat of combustion out through the cracked head or head gasket into the coolant stream, causing air and boiling coolant to circulate into the expansion tank, where you see it bubbling off into the atmosphere.

If no boiling or bubbling in the coolant resolution, your sea water mixing problem is elsewhere in the engine - maybe the raw water pump as others have suggested. I've never had a pump that could do this, as all my engines have had only a shaft driving an external pump.

Anyway, it would be very interesting if you could post the outcome! Good luck.

[sailorchic34]

Does the engine have a oil cooler?? Normally that is raw water cooled and in my eye's is a very likely source for the water/salt in the oil. Easy to check, simply bypass the raw water around the oil cooler and look for an oil drip out the water ports with the engine running.

[Hoodsail]

Good Morning: Hansen Marine (Marblehead, MA) inspected westerbeke diesel and found: no signs of water/coolant in bilge,pressure tested cooling system-no signs of coolant or water leak. engine oil clean - no signs of water/coolant. checked rocker arm shaft-no water/coolant. ran engine - ran well/oil 60psi/temp 160. Did replace the siphon break as this was sticking and could have been source of water...Kismet 2 is now mine...planning on sailing/motoring her from Marblehead to Guilford, CT in about 1 week..thnks Dave