Oil leaking where dip stick connects to engine block

[Dominic Garofolo]

My port side Cummins 4BTA is leaking oil.

Engine runs fine but under load oil sprays out of dip stick connection. After prolonged operation the oil pressure drops to zero and I end up with about two quarts of oil in the bilge.

In order to prevent pollution I pulled the boat and it is currently blocked up on land.

Any ideas on what can be causing this?
It just started doing this on 7-18-20.

Engine serial numbers 46038383 and 46043905

Thank you,
DG

Topic

[Dominic Garofolo]

Boat is back in the water no oil issues. I did not change the check valve.

Sold the boat, new owner was satisfied with the sea trial.

Thanks for all the help, never would have expected it to be such a simple problem.

DG

[Francis Valerio]

Dominic

I believe your oil leaking issue was only presenting itself “under load”. If that is the case then if your boat is still in drydock than replace the check valve.
Not sure if you are back in the water so disregard if you are.

Certain things have to be tested while engine is loaded in order for problems to present themselves and determine if they are functioning properly.

ALSO*
Dan brought up a good point, check the actual hose to see if there is an actual blockage in the hose. I guess it is possible if oil sat there and could have sludged up.

[Dan]

Domenic,
The check valve (or the drain hose orientation from the Walker canister to the check valve) is probably where your problem is.

Make sure the hose from the canister to the check valve is all a downward path, don’t presume that its OK, follow the path of the hose when installed and confirm this,If the check valve is blocked with contamination, oil will back up the hose and the result will be what you’re experiencing.

Your aftercoolers may have been force fed oil from this situation and performance may be affected, looking at the pics of your engine it doesn’t look like they have been serviced in a long time, you may want to look into servicing them, specifically the salt water side to prolong the life of them as the housings are no longer available.
Some info

Aftercooler Disasters

[Dominic Garofolo]

Check valve located. Now what?
I got the engine started and no oil is currently leaking. Should the check valve be replaced or removed?

Thank you,
DG

[Francis Valerio]

I agree to check that other hose for the check valve.

The presence of the oil in the walker system would be expected in my opinion based on the oil “pushing” out the dipstick when under load.

We need to determine what is causing the system to not vent the “gases” back into air intake.

Find that check valve…

[Dan]

You probably should follow this hose back to where it drains oil back into the engine and look for a check valve

[Dominic Garofolo]

Okay disassembled Walker air sep completely. The small filter had a lot of oil in it. Cleaned everything and reassembled. Of course batteries are dead so now I have to charge them. When that happens I will check in again.

[Dominic Garofolo]

Thanks for the reply.
Sounds like a game plan, but I cant get to it until Saturday.
I’ll let you know how I make out.
Hopefully its that simple.

Thanks,
DG

[Francis Valerio]

Lets simplify this.

First off, I am no expert but I can hold my own mechanically. I am not familiar with this particular system but the purpose of it is to take the dirty oily air that the crankcase is venting and send the dirty stuff back into the engine via the air intake.
It then filters the “clean” air to vent to the atmosphere. (kind of separates it)

If this system gets “fouled” or “gunked up” then the result would be an over-pressurized crankcase which is what you have as a problem.

I would remove the system and take it apart the best you can to see what appears to be “plugged up”.

It seems that the “check valve” is a common problem. I understand you have not located the check valve yet but I am sure it is there and you will find it.
I also understand that sometimes you have to be a contortionist to access some areas in a boat engine room.
I would use the other engine for reference, to help navigate the “blind side” of the troubled engine, if that is the case.

I would NOT suggest swapping parts from one engine to the other for troubleshooting (I would NOT). I say this because when your crankcase is over pressure it could potentially push out a rear or front seal. It will find the weakest point to vent. Dipstick in your case luckily and if you tried on the other engine it may find a different weak spot. Also in your case it only happens under load so you cant really do proper testing with one engine for a sea trial.

1 user thanked author for this post.

Rob Schepis

[Dominic Garofolo]

Thanks for the reply.
Haha I too wish you had come to help me out.

I just need to know what to do, I am certain I can do it.

Thanks,
DG

[Francis Valerio]

That Walker system is surely the culprit here. You crankcase is getting pressurized.

I was just in Wildwood Crest for last week, I would have surely came by and gave you an hour or two. too bad I would have like to have helped.

You just got to get into the system a bit and figure it out, listen to these guys advice they are experts

[Dominic Garofolo]

No check valve

Thank you for the reply.

Yes it’s definitely the dipstick connection that oil come out of when the engine is running.

I looked everywhere for a check or plug including where it’s shown on your picture. Sorry therefore no picture.

Thanks
DG

[Dan]

Dominic,
It may help Tony to diagnose this issue if you include a pic of the check valve and the hose routing from it to the airsep canister.

Attached is a pic of the check valve, also a pic of the location (mine has been removed and capped off )

Also confirm where the oil is coming from, are you sure its out of the top of the dipstick tube?

[Dominic Garofolo]

Walker air sep

Please see attached pictures.
I noted a small amount of oil at the small filter where it connects to the hose.
If you need more pictures please let me know.

Thanks
DG

[Tony Athens]

You need to post really good pics of what you are dealing with– The entire Walker system and hose routing..

I will “un-confuse” you if you post good pics..

Tony

[Dominic Garofolo]

walker air seps

Thanks for the reply.
I do still have the walkers.
There are two filters and I assume an oil line. Where would the oil be, I’m a little confused.

Thanks,
DG

[Dan]

If your still running walker airsep’s I would confirm it isnt filled with oil, the hose routing is flawed by design and you will end up with this exact scenario (mine did what you are describing when the engines where relatively new)

Changed the oil recently? overfilled? there’s some good articles on the B motors and oil dipstick levels in Tony’s tips on here.

[Author]

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