Engine smoke and sheen on the water

[Wotname]

Originally Posted by Mastermuffin

I used the same gearbox that came off of my previous engine, think the ratio is 2:1. not sure what prop size and pitch is.



Did a leakdown test when engine was cold


Cylinder 1: 16% leakage past rings
Cylinder 2: 10% leakage past rings
Cylinder 3: 10% leakage past rings
Cylinder 4 17% leakage past rings


Weird thing was cylinder 2 and 3 would sometimes have 60% leakage past the rings. i did the test multiple times and sometimes they wouldn't engage.



i get a compression tester today so maybe ill get a chance to test that tomorrow.

Please remember the rings won't be seated yet. However this is a good baseline for future testing.

[Mastermuffin]

So I'm pretty sure the head gasket is bad, at least when the engine is cold.


got this picture from taking out the glow plugs and sticking a endoscope



Starting when cold the engine now misses and dies a few times.



Yesterday i noticed smoke coming out of the anti freeze, and i got a video. Today i took another look only to find that all of the antifreeze is gone! it somehow disappeared when the engine wasn't running. I turned the engine over by hand and it wasn't hydro-locked, cranked it over with the fuel shut off as well.

https://www.youtube.com/watch?v=IyhYV33_9BI

I'm very confused on where it went... not in the oil and i cant imagine the cylinders could hold it all. Also checked the bilge and no signs.

[Scubaseas]

16%,17% leak down is fine especially with new rings.
There should be zero smoke out of the coolant. If you don't see it , the coolant may be going out to the exhaust through the heat exchanger, exhaust manifold or possibly a cracked head BUT a cracked head would give you all kinds of symptoms you are not observing.

It's possible the exhaust manifold aka heat exchanger housing is the source of the smoke in the expansion tank/coolant reservoir but much more likely the head gasket is letting compression gas into the coolant jacket. I'd try retorquing the head bolts before anything drastic is done.

Don't assume the coolant loss is the source of the smoke in the reservoir.

If you add a tracer dye to the coolant that will tell you where the coolant is leaking, even more if you have a back light. Check the inside of the water lift muffler for coolant.

If I was looking at it I'd put some tracer dye in the coolant to locate the leak. Your FLAPS would have this. I'd also put a pressure tester on the coolant reservoir and see if it continually builds up pressure. Autozone rents/lends cooling system pressure testers. If it does build up pressure then see below to diagnose which cylinder is at fault.

Any hypothesis you form should be proofed. Bad head gasket usually has other symptoms which you do not note.

Compression test will probably show as fine but if you had a fitting to check the leak down you can also try putting air in each cylinder to see if you get bubbles in the cooling system. If you did a leak down test you should be able to reproduce the smoke in the cooling reservoir if patient and looking specifically for that issue. Hard to get the engine on a firing position and locked in place but it would confirm a possible head gasket or cracked head issue. Get it in leak down and put a pressure tester on the coolant reservoir. If you have a head gasket or head issue the pressure on the cooling tester should continually increase as long as you have pressure on it.

[Compass790]

I did suggest head gasket leak in post #7. I believe u can get test kits for that. However yr vid looks like a smoking gun pointing to gasket to my shade tree eye.
My shade tree eye is not too good at looking at vids compared to real world tho.
Hope thats all it is, rebuilder should fix it but agree with scubaseas try retorque 1st.
If head proves to be a bit dodgy in flatness I've had very close to 100% success using Loctite 515 or 518 & no they aren't my spomsor but they shud be.

[Mastermuffin]

Originally Posted by Scubaseas

16%,17% leak down is fine especially with new rings.
There should be zero smoke out of the coolant. If you don't see it , the coolant may be going out to the exhaust through the heat exchanger, exhaust manifold or possibly a cracked head BUT a cracked head would give you all kinds of symptoms you are not observing.

It's possible the exhaust manifold aka heat exchanger housing is the source of the smoke in the expansion tank/coolant reservoir but much more likely the head gasket is letting compression gas into the coolant jacket. I'd try retorquing the head bolts before anything drastic is done.

Don't assume the coolant loss is the source of the smoke in the reservoir.

If you add a tracer dye to the coolant that will tell you where the coolant is leaking, even more if you have a back light. Check the inside of the water lift muffler for coolant.

If I was looking at it I'd put some tracer dye in the coolant to locate the leak. Your FLAPS would have this. I'd also put a pressure tester on the coolant reservoir and see if it continually builds up pressure. Autozone rents/lends cooling system pressure testers. If it does build up pressure then see below to diagnose which cylinder is at fault.

Any hypothesis you form should be proofed. Bad head gasket usually has other symptoms which you do not note.

Compression test will probably show as fine but if you had a fitting to check the leak down you can also try putting air in each cylinder to see if you get bubbles in the cooling system. If you did a leak down test you should be able to reproduce the smoke in the cooling reservoir if patient and looking specifically for that issue. Hard to get the engine on a firing position and locked in place but it would confirm a possible head gasket or cracked head issue. Get it in leak down and put a pressure tester on the coolant reservoir. If you have a head gasket or head issue the pressure on the cooling tester should continually increase as long as you have pressure on it.

The symptoms have changed a bit from my initial post, the engine used to start right up, now its hard to start and misses until warm. Also i didn't notice any major coolant loss until recently. There's a lot of smoke coming out of the coolant tank now, and tons of white smoke on startup. It seems to get better as the engine heats up. This could also explain the blue smoke because there are oil passages on the front and back of the head.

https://www.youtube.com/watch?v=KynExki_Mfs

[Scubaseas]

The symptoms have changed a bit from my initial post, the engine used to start right up, now its hard to start and misses until warm. Also i didn't notice any major coolant loss until recently. There's a lot of smoke coming out of the coolant tank now, and tons of white smoke on startup. It seems to get better as the engine heats up. This could also explain the blue smoke because there are oil passages on the front and back of the head.

Looks like head gasket or cracked head are possible. White smoke should smell kind of like rotting apples from the antifreeze in it. Or more like steam than oil smoke if you don't have antifreeze in the coolant. I would retorque the head and see if that solves the symptoms. READ the manual and follow the torque pattern diagram. If problem not solved pull the head off and inspect head and gasket carefully.

[Bigggwilly]

Hi Mastermuffin,

Did you reach a conclusion on this?

- A curious onlooker also with a MD22 with a bit of sheen and smoke. (Not as much though)

[MaritimeTees]

Did you ever get this fixed? I have the Volvo 2003 and have same issue and mine is the injectors unburnt fuel is the culprit. Injector shooting fuel out. It had same symptoms as yours. Replaced all 3 injectors. I never had loss of power or anything else. The smoke was bothersome. Most said leave it alone but i just fixed it.