Perkins diesel needing more oil after a 4 hr cruise

[edwmama]

Hello sailors

My original cal cruising 46 hull no 5 came with a Perkins 4.236 engine

For years I could only do max of 14 to 1600 RPM on cruising (6-7 knots)

After much trouble turns out the injectors where clogged or partially clogged

And the marine growth build up in the heatexchanger impeded cruising at higher RPM

cuz of over Heating


NOW that I've got all that resolved, the boat wants to fly

Now I can do 2200 to 2400 RPM in a heartbeat and cruise at 8.5 to 8.7 knots

And water gushes out in the back exhaust like Niagara Falls

What I have discovered now is,

After a 4 hrs trip to Catalina island, (from Marina del Rey ) a mere 28 nautical

Miles away, my engine oil is LOW and requires a top off 1 to 1.5 quarts of oil!

ITS BURNING OIL at much higher rpm

The engine runs smoothly, no overheating no black or blue smoke, good sound

I do see a slight white fog coming out of the exhaust but that may

Be from the coldness of the water and the fact the exhaust spends 1/3 of time

Underwater while cruising

But this oil loss is really annoying and worrisome

The engines runs so well though

The engine hours barely reads 1250 hrs

Had the injector pump and injectors rebuilt last year

The oil and antifreeze is clean, no cross contamination, no visible leak anywhere

Any advise?

I have not tried running at just 15-1600 to see if this persists

Would appreciate any thoughts




Edwin
Cal Cruising 46
MdR
[IMG][/IMG]

[model 10]

I fear your engine is clapped out. Go back to low rpm operation.

[CSY Man]

I and a Perkins 4-108.
It would take 1 quart of oil every 100 hours.
More if sitting for weeks/months between cruises.

I am afraid your engine has a serious problem, or if you are lucky, a serious leak
in the oil system/oil cooler.
If you see no external leakage that can be fixed, you are out of luck.

[edwmama]

Originally Posted by CSY Man

I and a Perkins 4-108.
It would take 1 quart of oil every 100 hours.
More if sitting for weeks/months between cruises.

I am afraid your engine has a serious problem, or if you are lucky, a serious leak
in the oil system/oil cooler.
If you see no external leakage that can be fixed, you are out of luck.

Thank you
I guess I better get a diesel mechanic


Edwin

[sailorchic34]

If your engine starts easy when cold, then odds are the engine itself is ok.

I would check if your oil cooler has a pinhole leak in it, leaking oil into the raw water. I'm betting that is where the oil is going. Quite common.

If your engine is a bitc* to start when it's cold, then you might have bad rings in one or more bores.

However loosing over a quart in 4 hours is a huge loss. My yanmar would burn a quart in 12 hours and all rings on one cylinder were broken.

[Lepke]

The engine hours may not be correct. You're burning more oil because you're working the engine harder. You were probably about half the rated hp @ 1600rpm and near the top at 2400, depending on the prop. Carbon builds behind the rings expanding them and better sealing the cylinder, and carbon could have been burned out at higher temperatures. Just because the coolant temps are ok doesn't mean your exhaust gas temps aren't too high.
Diesels like to burn oil because it's similar to fuel. Other ways oil can get into the combustion process is valve guides, turbo bearings, some injector pumps, crankcase breathers. In generator engines, long hours at light load can cause cylinder/sleeve glazing. Maybe similar to running your engine at low rpm for many hours.
Compression/leak down test would tell much. At the dock, does the exhaust create an oil sheen?

[edwmama]

No oil sheen
No evidence of oil in the exhaust water
Engine starts right away, no hesitation
Runs very smooth no vibration no black or blue smoke ( slight white smoke)
The coolant and oil is clear, no contaminants of any kind
Engine doesn't overheat at max rpm 2200 or close to 2400

It's just that for years and years I've only run the engine at 1500 rpm ( no higher ) as engine was unable to- partially blocked injectors and marine growth-
And never noticed any oil consumption

Now that I am able to achieve much higher rpm, this is a new finding

How do I diagnose leakage in the oil cooler if there any
Again the exhaust sea water no NO oil in it



Edwin

[donradcliffe]

Because its a Perkins, my guess is 80% or more of the oil you lost was through leaks--look in the bilge for the missing oil.

[DeepFrz]

Has the engine done this more than once? I'm wondering if you didn't add enough oil after an oil change and so you just thought you burned that much oil???

[jimbunyard]

Given that history, and if you're sure that the oil isn't leaking or that the loss isn't an artifact of faulty memory, it isn't uncommon for the oil control rings in an old engine to lose a certain amount of tension.

Conversely, problems with the injectors or injector pump can cause cylinder wear or glazing. Wear requires rebuilding, if this is the case you're lucky; parts are available everywhere for very reasonable prices. Glazing might correct itself with higher rpm running or may be alleviated somewhat with an alternating plan of high load, high rpm running with a lot of variations in engine speed.

This engine should be run with a high quality, non synthetic oil; a recent change to synthetic could result in the symptoms you're experiencing.

If the engine starts quickly, has reasonably good oil pressure, doesn't overheat, and revs to maximum, probably the only thing you have to worry about is a failed emissions test. It is possible to be burning that amount of oil in an engine with good compression without an excessive quantity of smoke.

A knowledgeable, experienced, communicative mechanic will give you some peace of mind in dealing with the issue.

[edwmama]

Originally Posted by DeepFrz

Has the engine done this more than once? I'm wondering if you didn't add enough oil after an oil change and so you just thought you burned that much oil???

Yes it has happened a few times since I was able to run at a much higher rpm


Edwin

[zeehag]

my perkie hs alwaysbeen good on oil.
if it wasnt in the oil pan it was in the diesel tank. funny how lift pump fail will do that. but even until it ranaway i had no issues with it eating oil.
have fun.
i covet your 236.
i have the best engine builder. he would love to massage your engine.

[Triumphant]

I had an oil leak on my 1984 4236M, it went from leaking nothing to 1 pint an hour.

We eventually found that it was caused by a hole at the bottom of the dip stick tube where it attaches to the nut going into the block and it only leaked AT 1500 RPM AND ABOVE so it was not too easy to find.

We replaced the tube and we are back to normal again.

[Roniszoro]

There is a reason that the English have not been building computers. They have not, as yet, figured out how to make them leak oil!

[Wulf]

😂😂😂 Thanks for the morning giggle!!

Originally Posted by Roniszoro

There is a reason that the English have not been building computers. They have not, as yet, figured out how to make them leak oil!