1994 mercruiser 5.0 carb’d started ticking

[Marko_f1]

Hello everyone! I bought a 1994 Bayliner 2452 with a carb’d 5.0 mercruiser a few months ago and just used it for the first time a couple of days ago. The boat sat for about 3 years before I bought it but it fired up and ran pretty good. On my first day I replaced the leg oil and fuel water separator filter and added a fuel system treatment to the first tank of gas (78 gallons). I went about an hour offshore and the boat was fine the entire time, until I started heading back and then noticed it developed a sort of ticking noise, as if a coil of wire was stuck in the engine.

I replaced the oil/filter and spark plugs yesterday. The spark plugs were pretty wet and most had a little carbon build up on them. The engine starts a lot easier and runs much smoother however, the ticking sound is still there. It seems to be coming from the left/starboard side of the engine towards the rear. I opened the left valve cover to check if I can see anything out of the ordinary (with my limited experience of engine internals) and I noticed the rocker arms and push rods had some play side to side while other ones were stiff/had no play.

Here’s a quick video I took and posted on YouTube where you can hear the noise: https://youtu.be/rtqJtW_9oJw

my question is, does anybody on here have an idea what this might be? Let me know if there’s any other details that are needed to get a Better idea of what the issue may be.

thank you in advance for your help!!!

 

[Bondo]

from the left/starboard side of the engine

Ayuh,...... Welcome Aboard,...... The starboard side is the Right hand side,..... port is the left hand side,......

That short vid sounds like a massive exhaust leak,......
At idle, run yer hand all around the exhaust gaskets,.....
When ya find the leak, you'll know from the heat,.....

 

[Rick Stephens]

Welcome to iBoats forum Marko. Another consideration is there are flappers at the top of the exhaust Y pipes that keep water from surging into the engine. If the motor was ever gotten hot they can burn off the rubber and they tick pretty loud at idle. Your video does sound like a major exhaust leak, as Bondo stated.

Also like to note a couple safety considerations. A new to you used boat was an old to someone else neglected boat. Always assume none of the maintenance was done before you got the boat. You should get the Mercruiser manual for your boat, (not an aftermarket manual!) and do all the scheduled maintenance. Assume none of it was done. It scares me more than a little that you took the boat on your maiden run an hour offshore. So many things can go wrong and it is a looong walk back.

Enjoy your new boat. Here's the right place to figure out how to keep it running.

Rick

 

[Marko_f1]

Ayuh,...... Welcome Aboard,...... The starboard side is the Right hand side,..... port is the left hand side,......

That short vid sounds like a massive exhaust leak,......
At idle, run yer hand all around the exhaust gaskets,.....
When ya find the leak, you'll know from the heat,.....

I always mix them up but I think I’ll finally remember this now thanks for correcting me and also for your help. I thought that’s what it may be at first but for some reason I thought it may be something more serious such as issues with the valves so here’s to hoping it is in fact an exhaust leak!

 

[Marko_f1]

Welcome to iBoats forum Marko. Another consideration is there are flappers at the top of the exhaust Y pipes that keep water from surging into the engine. If the motor was ever gotten hot they can burn off the rubber and they tick pretty loud at idle. Your video does sound like a major exhaust leak, as Bondo stated.

Also like to note a couple safety considerations. A new to you used boat was an old to someone else neglected boat. Always assume none of the maintenance was done before you got the boat. You should get the Mercruiser manual for your boat, (not an aftermarket manual!) and do all the scheduled maintenance. Assume none of it was done. It scares me more than a little that you took the boat on your maiden run an hour offshore. So many things can go wrong and it is a looong walk back.

Enjoy your new boat. Here's the right place to figure out how to keep it running.

Rick

First of all, thanks for all the great advice Rick! I read up online earlier and actually checked those flappers and they seemed ok, will have to check around the exhaust manifold tomorrow and see if I can feel any Exhaust leaking out.

I know me taking the boat out that far for the first time wasn’t the wisest thing. I actually thought about what else I should/could do in terms of maintenance after changing out the engine oil/filter, spark plugs, leg oil and fuel water separator filter. It seems getting a manual would be the best way to learn more about maintenance and see what else should be some.

Thanks a lot to both of you for taking the time to help and offer great advice for a novice boater such as myself!

 

[AShipShow]

Welcome to the forum Marko... Great advice above... I don't know what took me so long, but I just bought the Merc manual for my 5.7 off ebay in great shape for cheaper than a new impeller... Its a great investment and one I will now recommend be everyones first investment...

As Rick stated, a new to you boat means you need to start from square 1 with maintenance... In addition to all lubrication, add to your list replacing the impeller, bellows, cap and rotor. Also, do a thorough inspection of you gimbal bearing, ujoints, all anodes, shift cable adjustment, check the ignition timing, pressure test your drive... Thats might all seem like overkill but if I'm going an hour offshore, plan on the worst case scenario...

 

[QBhoy]

I would normally say that’s an exhaust leak. But I think you may be running on 7 cylinders there perhaps. That would suggest you may have a lose or missing spark plug perhaps.
If it is an exhaust leak...get down there with a bit of paper and hold it around the exhaust and you’ll see it flapping for sure.

 

[Marko_f1]

Thanks again for all of your help and invaluable advice fellas! I started up the engine in the morning and ran my hand underneath the exhaust manifold and sure enough it was blowing like crazy, turned out to be loose bolts so I tightened them up and the sound is gone. Previous owner told me he replaced the manifolds and risers before he pulled it out of the water last time so whoever did that job clearly didn’t torque those bolts.