Is my engine dead?

[Goofeyfoot]

Is my engine dead? The engine is a Volvo MD 2020 in a 33 foot sailboat. The engine was produced in approximately 2001.

This summer my boat overheated. The collar on the heat exchange came separated from the heat exchange tank and blew out all the coolant. The engine stopped dead ss a result.

This summer the mechanic put in a new heat exchange tank and that side of the engine works fine.

However, now the engine belches white smoke all the time. It doesn’t go away after you run the boat for awhile. So I’m thinking that something happened in the overheat situation, maybe a head gasket or something blew. I really don’t know much about these things.

So I guess the question is, given that the boat overheated, that a gasket blew, am I now foolish to continue to repair the engine? Should I chuck the engine? Should I fix it? What’s the likelihood that it will ever be right?

As I said I don’t know much about these things I just don’t want to buy repairs that will just put the engine on life support.

Thanks.

Michael

[Lepke]

Overheating can do anything from no damage to major damage. It depends on how hot for how long. Since you know little about engines, you'd probably be better off with a new working engine. Spend the money all at once instead of one part at a time.The average marine isn't going to be much help except for emptying your wallet.

[Spider0804]

White smoke in exaust is the signifier of head gasket blown.

I have changed a couple head gaskets on vehicles, they are more time consuming than anything to change. You are taking the top half of the motor off.

There should be an owners manual for whatever engine it is with a step by step to take it apart and replace it, keep the engine in time, and put it all back together.

To tell if your piston rings or cylinders are fubar you can grab a compression tester and turn the engine over and compare what you get with the manufacturer spec, compression goes down slightly as hours on a motor pile up in most cases, so it can be a little off.

If thing is starting, not running like crap, and not knocking, the chances are the engine is not fubar though...People do this to cars fairly often and a real good portion of the time the engine can be saved...or they just opt to drive it around forever until it looks like a fog machine.

Good compression, change the head gasket.

A head gasket for a car is 100 bucks or so but marine anything is expensive so probably double.

Worth a try before you drop a buttload of money on an engine.

If you are not mechanically inclined at all and/or do not have a pair of sockets and wrenches you could buy what you need to pull the motor and take it to someone.

At the very least have a mechanic come aboard your boat to test compression and give you an opinion.

[Uncle Bob]

Mate, given that you acknowledge a lack of experience with engines I would suggest a decent mechanic be employed to at least identify the problem and quote to repair it.
How to find a good mechanic? Simply ask at least six boatowners at your marina, you should get at least three that would recommend the same one, contact that one and see if they can assist.

[wingssail]

Originally Posted by Lepke

Overheating can do anything from no damage to major damage. It depends on how hot for how long. Since you know little about engines, you'd probably be better off with a new working engine. Spend the money all at once instead of one part at a time.The average marine isn't going to be much help except for emptying your wallet.

Seems like bad advice. He most likely has a bad head gasket so advising him to spend $20,000 on a new motor is absurd and impractical. Get a good mechanic and figure out what is needed. Period.

[deblen]

http://www.marinesurveyorontario.com/volvopenta.pdf


http://www.marinesurveyorontario.com...riesm25m30.pdf


https://www.cruisersforum.com/forums...-158867-2.html


I installed one of these. http://www.borelmfg.com/products_alarm.htm



Your Volvo Penta MD 2020 is made by Ischibaura & is called an M20 by Perkins.


Cheers/ Len

[SalingSue]

I don’t think the engine is toast.

But a rebuild, at least a top rebuild sounds in order.

I’d start thinking of how to remove the engine from the boat, I’d also start asking around for the best place to do it, get the manuals and find a good local diesel guy, most of the marine engines arnt exactly complicated.

Also do you just have a dummy light, or do you have a temp gauge for the engine? I’d get a gauge and know where the engine likes to run, if it starts to climb, shy of a emergency situation, shutdown and figure the issue out.

[sandy stone]

Sure sounds like a bad head gasket, if the smoke is white and not blue. If the engine runs OK besides smoking a lot, you probably don't have that big a problem. If you pay somebody else to do all the work, it could probably run to $2000 or so (roughly10% the cost of installing a new engine), since once you have the head off you might as well get the valves and injectors serviced. Likely your biggest challenge will be finding a mechanic you can trust.
You didn't say what kind of boat you have, but I can't imagine you would have to remove the engine just to pull the head.

[mvweebles]

Originally Posted by Spider0804

White smoke in exaust is the signifier of head gasket blown.

I have changed a couple head gaskets on vehicles, they are more time consuming than anything to change. You are taking the top half of the motor off.

There should be an owners manual for whatever engine it is with a step by step to take it apart and replace it, keep the engine in time, and put it all back together.

To tell if your piston rings or cylinders are fubar you can grab a compression tester and turn the engine over and compare what you get with the manufacturer spec, compression goes down slightly as hours on a motor pile up in most cases, so it can be a little off.

If thing is starting, not running like crap, and not knocking, the chances are the engine is not fubar though...People do this to cars fairly often and a real good portion of the time the engine can be saved...or they just opt to drive it around forever until it looks like a fog machine.

Good compression, change the head gasket.

A head gasket for a car is 100 bucks or so but marine anything is expensive so probably double.

Worth a try before you drop a buttload of money on an engine.

If you are not mechanically inclined at all and/or do not have a pair of sockets and wrenches you could buy what you need to pull the motor and take it to someone.

At the very least have a mechanic come aboard your boat to test compression and give you an opinion.

I don't understand this. How would it have goof compression with a blown head gasket?

Swapping an engine is pretty easy if it's like for like. Where it can get a bit expensive is if you change engine makes and have to mess with engine mounts, transmission, and coupling. A new engine is in the $10k range for one this size (without gear). A rebuilt one is about half that, but was probably an engine like yours is now before it was rebuilt, so you might want to consider rebuilding yours. Will avoid messing around with mounts. But a decent mechanic would be your best source - no way to tell from internet.

BTW - testing compression on a diesel is significantly more difficult than a gasoline engine. Involves sourcing an adapter for the injector - the universal adapter kits are notoriously un-universal, and a test gauge that will go to 300 psi or higher. Unless you find a factory mechanic with the specialized adapter, it's not something he can easily do without spending s bunch of time scurrying for parts.

A crude measure of compression past rings in to see if there is excessive blow-by. This is manifested as high crankcase pressure - remove the oil fill cap when running. If there is a lot of air escaping - say, enough to float a paper towel, your rings are shot.

If there is decent access to your engine, getting the head off will not take more than a few hours, call it a day by the time a mechanic gets setup and gets the head go a machine shop to make sure the surface is flat and replace the valves and seals. Volvo parts are at the upper end compared to other brands. When the head is off, he can see if there is excessive scoring in the cylinder walls, a sign of greater engine damage.

Good luck - sorry for your troubles.

Peter

[LittleWing77]

Originally Posted by sandy stone

You didn't say what kind of boat you have, but I can't imagine you would have to remove the engine just to pull the head.

It's a boat that's got a Volvo engine in it. As they are among the best engines out there, I would venture to say that the boat is similarly worthwhile (who knows about engine-access, though, I'm supposing that's what you were getting at).

Michael -
Not that I would say that it's easy, but we pulled our Volvo out of the boat (hung it in the saloon using blocks and pulleys) and replaced the head gasket in the middle of the South Pacific (Vanuatu). The "worst" part was waiting for the two weeks it took for the gasket to arrive via Federal Express.

And we were two chicks with not much marine engine experience outside of changing filters... (We were lucky that one of the crew at the time was a big bruiser of a Maori guy who provided some muscle)

Who were our expert consultants? Our dockmates. The Sailing Community.
Talk to your fellow sailors!

Uncle Bob's advice that you ask for six mechanic recommendations from people in your marina is pointing you in the right direction.

Sounds like you have a time-consuming project, but not a catastrophic engine failure.

Fair winds!
Warmly,
LittleWing77

[rslifkin]

Originally Posted by mvweebles

I don't understand this. How would it have goof compression with a blown head gasket?

I've seen coolant leaks into the cylinder from a head gasket or cracked head that didn't cause low compression. The failures can be strange. I've seen some pressurize the cooling system with combustion gases and not lose coolant, but others drink coolant and never seem to push anything into the coolant.

[NCboatrx]

@ Goofeyfoot. You definately need a mechanic but mabye not for a rebuild. Some important information is missing so please answer the following questions.
1) does the engine use any coolant?
2) does the engine start quickly from cold?
3) if there is a temperature guage fitted, what temp is the engine running at when warm?
4) is the oil clean on the dipstick?
5) is the coolant clean when you take the cap off?

[Pete7]

^^^^^ This first before we start tearing down engines. Add number 6, when the engine is warm are there any large bubbles in the coolant tank?

Pete

[deblen]

Recommend carrying one of these.There are many versions./ Len


https://www.amazon.com/8MILELAKE-Rad...7962344&sr=8-3

[cottonsail]

Pull the head to change the head gasket, but how are the piston rings? Here's a simple ring test. With the head off turn the crankshaft until all the pistons are at an even position in the cylinder. Now fill each cylinder with diesel fuel or kerosene. Comeback the next day. If you lost a little of the fuel your rings are good. If the cylinder is empty the rings are worn out.