A horrible sight after overheating and oil leak

[fossilfool]

Hello A4 afficionados. I am seeking your guidance. I was motor sailing in the Oakland shipping channel towards Jack London Square. After 30 minutes I began to hear a harsher sound on the RPM of the motor for about 5 minutes, then suddenly the sound improved to more of a thrumming, but at the same time I felt a loss of power, and increasing the throttle didn't do anything to lift the RPM past 1800. Then a minute later, we had white smoke coming out the engine room blower exhaust. During this whole time the engine's water intake was open and the water exhaust system was performing correctly.

At the dock the next morning we measured the oil and it was low, so we added 1.25 qts oil. The engine sounded normal and no smoke, so we tried to motor out of the channel. But after 15 minutes, another loss of power, and more white smoked. We sailed slowly home to Berkeley with very light winds, but occasionally we did use the motor for a minute or two here and there to get out of the way of a ferry, to get away from one of the towers of the Bay Bridge. We kept checking oil and added oil twice more. It was dropping to low on the dipstick quickly.

At 430PM we were still a mile off the entrance to the Berkeley harbor so I ran the motor for a good 6-8 minutes to get to harbor and it performed fine, giving decent power at 2000RPM.

We ran the motor again to assist with docking. I gave a blast of reverse to stop the boat as we sailed into the upwind slip.

The boat is a 1973 Cal 33.

After the sail I took a close look. I saw that most of the 3 quarts of oil we'd added was on the floor under the motor. I saw about 2" water in the bilge that was not oily. And most troubling, I saw 2 large pieces of metal on the floor under the starboard side of the motor. One of the pieces was painted the same color as the motor, about the size of a playing card and looks like it's part of the motor itself. And the other piece looks like a cap of some sort that was partially damaged. The photos are taken on top of the transmission cover for scale, but were found on the floor under the right side of the motor.




I looked at the 360 view and the manual and didn't see the round cap. Do you know what it is? I will try to get back to the boat and feel with my hands where they might have fallen off.

The situation feels very discouraging. It feels like I may have ruined my 50-year-old engine and I only purchased the boat in the last few months. I know I must have made a beginner mistake and I'm disappointed in myself. We did service the boat about 6 months ago and changed the oil at that time. I would estimate that I did about 20-30 engine hours since we drained and added oil. Performance had been reliable. I guess I took the motor for granted but also, something really bad must have happened for there to be metal on the floor like this. The engine has about 1200 hours on it.

The only bright spot, and also a confusing thing, is that the motor still runs! For short uses it does start up and go.

I would appreciate anyone who is willing to point me in the right direction. Thank you.

[Dave Neptune]

First welcome to the MMI Forum albeit a probably sad one.

I am going to guess the piece of metal is from a hole in the pan which explains the massive oil leakage.

As far as the "cap" looking piece I have no really good idea. It does look a bit like the top of a piston though but the diameter seems to small. The hammered edges do indicate it may of been taking a beating. If the beating was inside the engine then a rod journal probably punched it through the pan or side of the block. The water in the bilge also may indicate a breached water jacket inside or outside the engine.

Feel all around the underside and or inspect with a camera or a mirror.

I think the engine will need to come out and hopefully it is repairable.

Do you have some engine experience?

Dave Neptune

[zellerj]

Welcome to the forum, and good luck with your new boat.

The cap looks like a fill cap that one finds on the deck for water and gas. The other piece does not look like it comes off of your Atomic 4 either because it is a different color and not rusty. If it is part of the motor, is it from the oil pan? I don't know what could rip off a piece of the oil pan, but whatever caused it can't be good for the engine.

Smoke in your cabin? This could be from a leaking exhaust - have you inspected your exhaust?

I would do a compression test - low compression could mean bad rings, which would be the source of the white smoke. Bad rings could mean the engine is burning oil, and would account for some of your loss of oil. The exhaust of an engine burning oil is usually darker and not white steam. Or very low compression could mean a bad head gasket that allows cooling water to get into a cylinder or two and that also causes steam in the exhaust.

But you find oil under the engine - so you have a leak - could be a bad oil pan gasket or there are some drain plugs that might be leaking (or a chuck missing from the pan itself). A good way to find oil leaks is to clean the engine well, and after running, look for oil tracks.

To track down the source of noise, a stethoscope helps to isolate the source.

The hardest issues to troubleshoot are intermittent issues - good luck in tracking these down.

[thatch]

Terminal

Hi, And a rather "dubious", welcome to the forum. Dave's assessment of what those parts are is correct. A quick look at my "paperweight A4 piston" verified that the round object is definitely the top portion of a piston. The other piece of metal will undoubtedly match the hole in the side of your oil pan. My guess is that when your engine ran low on oil, one of the connecting rod bearings seized starting a major destructive cycle of that rod and piston assembly. It was just a matter of time before the crankshaft "hammered" the piston through the side of the pan. The fact that your engine is still running is a testament to the durability of our great little engine. Unfortunately, it's time for you to do an engine replacement or some "extreme" repair work.
Sorry, Tom

[Dave Neptune]

The piston probably got stuck in the bore when it overheated then breaking off the top, not real uncommon as far as catastrophic failure is concerned. Then the hammering allowed to top to fall into the pan and be punched out the side or bottom of the pan. I have seen more than a few pistons torn in half from sticking in the bore and in some cases the engine was repaired.

I would pull the head to check for cylinder damage. If the cylinder is only slightly scathed a sleeve and hopefully a new pan may salvage the engine. Either way it will need to come out.

Post some pics as to what you find for further assessment as to salvageability.

Dave Neptune

[Al Schober]

I think Dave has it right. Top of a piston and a chunk of the oil pan.
As to piston size, they're a bit over 2.5". A magnet won't stick to aluminum, but it will stick to the bits that look like piston rings. A magnet will also stick to the piece of the oil pan. Adding oil and running the engine won't do you any good. Time to rebuild or replace the engine.
In your search for a replacement, you're unlikely to find one with the reduction gear. No matter, the basic engine is the same. You'll just have to keep the present rotating parts of the reversing gear to transplant into the replacement engine. I've done this job so let me know if you need assistance.

[fossilfool]

In your search for a replacement, you're unlikely to find one with the reduction gear. No matter, the basic engine is the same. You'll just have to keep the present rotating parts of the reversing gear to transplant into the replacement engine. I've done this job so let me know if you need assistance.

Al thx for your reply. Are you saying you can tell by looking mine has a reduction gear?

[fossilfool]

Post some pics as to what you find for further assessment as to salvageability.

Dave Neptune

I will come back to the forum with more photos and seek more guidance. It feels so tragic but I can also see the sequence of events leading to this and the warnings I received, like the knocking sound. So hopefully I can grow and be a better sailor from this.

[Al Schober]

Yes, looks like a reduction gear. Take a wire brush to that riveted nameplate just aft of the reversing gear.
What kind of boat is it? How is access to the engine? Will a hoist through the main hatch get to the engine or will you have to shift the engine fore or aft?

[fossilfool]

Confirming oil pan hole and piston destruction

We cleaned up the oil mess under the engine with kitty litter. I felt around and found the hole in the oil pan where the metal chunk was from. I also saw more piston parts on the floor and some trying to fall out the hole. The hole in the pan was under the starter motor, and this was in a poor location for the camera to access.

As you can see in the photos, the engine will have to be dragged forward then hoisted up.

Regarding the water... There was the 2" of water in the bilge, and this water had no oil, and there was also a bunch of water with a little oil aft of the engine. I don't know how the 2" of water got into the bilge. I guess there is a pathway to the bilge that bypasses the place where most of the oil collected.

The oil mostly collected under the engine. In the photos you can see I have been using that spot for one of the 2 batteries.

[zellerj]

Welcome to the forum, and good luck with your new boat.

The cap looks like a fill cap that one finds on the deck for water and gas. The other piece does not look like it comes off of your Atomic 4 either because it is a different color and not rusty. If it is part of the motor, is it from the oil pan? I don't know what could rip off a piece of the oil pan, but whatever caused it can't be good for the engine.

Smoke in your cabin? This could be from a leaking exhaust - have you inspected your exhaust?

I would do a compression test - low compression could mean bad rings, which would be the source of the white smoke. Bad rings could mean the engine is burning oil, and would account for some of your loss of oil. The exhaust of an engine burning oil is usually darker and not white steam. Or very low compression could mean a bad head gasket that allows cooling water to get into a cylinder or two and that also causes steam in the exhaust.

But you find oil under the engine - so you have a leak - could be a bad oil pan gasket or there are some drain plugs that might be leaking (or a chuck missing from the pan itself). A good way to find oil leaks is to clean the engine well, and after running, look for oil tracks.

To track down the source of noise, a stethoscope helps to isolate the source.

The hardest issues to troubleshoot are intermittent issues - good luck in tracking these down.

Boy did I screw up that diagnoses!!

[thatch]

"Four"ensics

Jim, Please don't beat yourself up too badly over misreading this engine's problem. It is quite common for the group to speculate widely before homing in at the root of a problem before collectively arriving at the most logical, cost effective solution. The camaraderie here is wonderful.
Tom

[joe_db]

BTW, the ground wire is missing from your shaft brush.

[fossilfool]

Possible re-use of the 2:1 reduction gear

Hi again,

After talking to both Don Moyer and Ed Richardson I have learned that my Atomic 4 isn't a good candidate for a rebuild and that I am probably not the right person to do it.

I have begun the process of going electric. I'm much more comfortable maintaining an electric system than a gas system. I've already built several electric bikes and one electric boat.

I am thinking about reusing the 2:1 reduction drive from my Atomic 4 because the electric motor is going to need one. Most people would go with a dedicated reduction drive with a belt, similar to this:


This is certainly an option for me.

The advantage of the Atomic 4's gear reduction is that it's inline, making for a low profile build, and it already has the exact coupler installed that's needed for my prop shaft.
My question is how to get the gear off. I removed the nut and all the allen head screws holding the gear plate on but it's not coming off. I hit the plate with a dead blow hammer and can see a separation but it's not coming off. I saw something inside the gear that looks like a thick C-clip but I think it's part of the gear. Can you offer any help in removing this gear and plate please? If I could remove the gear, I could probably make a coupler to the new electric motor, then run the old reducer with my new electric system.

[fossilfool]

Gear reducer in good shape.

I just want to add that the gear reducer looks to be in good condition. All the machine screws holding the gear reducer onto the block were able to unscrew with similar amount of force, and the gears inside look to be in good condition. I'm not an expert on how it's supposed to look but I don't see any broken metal pieces, just good gears with plenty of oil bath.