Mercruiser 3.0 Engine noise

[Dave1029]

99 Bayliner Capri 1950, bought cheap and had to replace head gasket, chirping while running.
Chirp is gone ran good on muffs, took out to lake for a spin. Adjusted timing and idle in the water was running ok when all of a sudden a clattering or knocking.

took video of engine after bringing it home, this is with outdrive removed as initially it sounded like noise was coning from there. During further investigation, noise got worse, almost like something broke and there were 2 noises combined. No video of this though

https://youtu.be/mLUeoFAX_0Y


Thoughts?

I’ll share answer when I find it.

 

[achris]

Pull the valve cover. Sounds like a broken valve spring.

 

[Dave1029]

Should have said, already pulled valve cover and all valves were still adjusted properly, I couldnfind anything amiss in the valve train, bit didn’t dig too deeply.

 

[achris]

Then it's a bigend knock... Engine out and strip...

 

[Dave1029]

Pull and strip next week, will post results

 

[tpenfield]

Probably wish you had the chirping sound back . . . I thought one of my engines had a chirping sound when I was working on them this past weekend, then I realized it was a bird in a nearby tree.

I'd double check the top end to make sure all is well before pulling the engine to check/rebuild the bottom end. Did you double check all of the valve springs to see that there is not a broken one?

 

[Dave1029]

For those interested, it was a piston making the noise, the number 3 cylinder is a mess, looks like a short block for my winter project.