02 LSV - loud clunk when trying to start

[vandy654]

Need your opinions. Had the boat out every weekend since early April with no issues what so ever. Took it out this past Saturday, made it about a half mile from the landing and the boat suddenly lost engine power (no abnormal noises or anything came from the engine), but continued to run. Looked down at the gauges and saw that the temperature was around 210. My boat usually consistently stays under 180. Shut it down and popped the engine cover. Nothing noticably wrong. I changed the impeller last spring. Let the engine cool down for a few minutes, went to try and restart it, and all it does is make a loud clunk noise when it appears to hit top dead center. Won't restart. Got towed in, dropped it off at my local dealer, they took a look at it today and they're not really sure what's wrong, they are going to have to start to tear open the engine to look.

Not sure if it was just coincidence, but my friend was turning on the stereo in the glove compartment when this happened. But that doesn't explain the high temperature.

I'm at a loss. This sounds expensive. The engine only has 350 hours on it.

Any opinions would be greatly appreciated.

Thanks.
Justin
'02 Outback LSV

[dru1974]

Wow doesn't sound good. I know these marine engines are tough hope all is not to major. Let us know what they find.

[mmandley]

Loud clunk when cranking makes me think you struck a valve, but i dont think these are interference engines.

Might have been hydro lock also, over heating the engine will cause the head gasket to blow out and dump coolant into the cylinder, if its on the compression stroke the water will lock the engine giving you a loud cluck as the piston and drive train are studdenly stoped.

Hard to say but loud clunk when starting and then not starting is typical of a major compent broken, and if there taken the time to open the engine then spend the extra money while its open and get the heads resurfaced and such as over heating effects the heads the most.

[vandy654]

So the dealer called me this afternoon and told me the engine was hydrolocked. 6 of the 8 cylinders had water in them, I'm not sure if he verifed that by pulling the heads off. He was concerned that both sides of the engine had water in the cylinders. This is odd as the engine was only running for about 10 minutes when this happened. I'm not sure what would of caused the engine to overheat, I just changed the impeller last spring, wondering if the engine water pump had a problem. He also told me that the exhaust manifolds were taken off before, probably from the previous owner, they were put back on with RTV, not with a manifold gasket. Compression checked out good as well I was told. Sounds like the heads need to be pulled, redone, and new head gaskets put on. Just wondering if there is something else up with the exhaust manifold.

[mmandley]

So the dealer called me this afternoon and told me the engine was hydrolocked. 6 of the 8 cylinders had water in them, I'm not sure if he verifed that by pulling the heads off. He was concerned that both sides of the engine had water in the cylinders. This is odd as the engine was only running for about 10 minutes when this happened. I'm not sure what would of caused the engine to overheat, I just changed the impeller last spring, wondering if the engine water pump had a problem. He also told me that the exhaust manifolds were taken off before, probably from the previous owner, they were put back on with RTV, not with a manifold gasket. Compression checked out good as well I was told. Sounds like the heads need to be pulled, redone, and new head gaskets put on. Just wondering if there is something else up with the exhaust manifold.

Sorry to hear about the Hydrolock, i had a feeling thats what it was. As for the Exhaust manifold gasket it doesnt effect the engine in the way of cooling or water entry. It will cause valve damage if its leaking, its called sucking a valve. So get the gaskets replaced of there pulling heads as this is a no brainer at this time.

I have a feeling the boat might have freeze damage and as soon as you started it it was dumping water in the cylinders but the engine was able to keep up and pump it out while it was running but as the engine heats up the cracks get larger and larger till they over come the engine, you saw the over heating problem and shut it down so it didnt blow the engine, im sure that was only a minute or two away.