Engine ticking 260 Sundancer

[Captain Gary]

Need mechanic advice. My 7.4L MPI Engine in my 1999 260 Sundancer has developed a ticking sound when idling. If I run it up to higher RPMs for for a minute or or so the ticking goes away but will come back after a few minutes idling again. The engine runs smoothly otherwise and operates fine under power. I’ve changed the oil and tried Rislone oil additive but no change. When having it winterized (at Skipper Buds near Oshkosh WI) they checked it and told me they’re not sure what it is but it’s inside the engine and would require a full engine rebuild to fix at an estimate of $10,000! I’m not buying it. Any mechanics out there have any ideas on what it might be? Or if an engine rebuild should cost $10,000 if that is really the only solution?

 

[Captain Gary]

By the way, not sure why I’m still showing as a new member having been on here for 3+ years but whatever.

 

[Wanderer 290]

How many hours? What is the maintenance history as you know it? Especially oil changes? Finally, what is the indicated oil pressure at idle and throughout the rpm range?

 

[Captain Gary]

About 350 hours on the engine and has decent maintenance history of oil changes and tuneups.

 

[Wanderer 290]

About 350 hours on the engine and has decent maintenance history of oil changes and tuneups.

Oil pressure indication at idle and throughout the rpm range?

 

[scoflaw]

Is it a clatter like all of the valve train or 1 loud one?
Clatter is normal and if it's just 1 you don't need 10k worth of work. That's a non adjustable valve train so it sounds like a collapsing lifter from what you describe

 

[Wanderer 290]

Is it a clatter like all of the valve train or 1 loud one?
Clatter is normal and if it's just 1 you don't need 10k worth of work. That's a non adjustable valve train so it sounds like a collapsing lifter from what you describe

GM’s hyd roller lifters from that era are known to fail.

 

[Captain Gary]

Thanks guys. Oil pressure is good and steady throughout range. Increases slightly at increased rpms but still around the 40 psi mark if my memory is right (boat is in winter storage now so can’t confirm). It’s a solo ticking sound not a clatter. Goes away for a few minutes if I run her up above 2000-2500 rpm or so for a Lille while.

 

[scoflaw]

leaky lifter. Might as well replace them all while you are there. Couple of boat bucks.

 

[B BARKER]

Can you tell exactly where the ticking sound is coming from ? up front, middle, rear ?

 

[Wanderer 290]

90% probability you have a bad lifter based on the description of symptoms. So $10k is for a new engine is just outrageous.
$200 for gm replacement lifters and 2 hours labor.

 

[Golfman25]

So I had the same issue in my Jeep Grand Cherokee. It was an upper end problem -- lifter, valve or something like that. I'd have to go pull the report. Did not require a full engine rebuild or $10,000. The reworked the top end and I have been good to go. Good luck.

 

[sbw1]

My 370 with 7.4s had a ticking sound. It was a lifter and it caused no problems for the 11 years I owned the boat. The price for the work seems outrageous given the cost of new crate engines.

 

[B BARKER]

I had a 7.4 do that years ago and it was coming from the front timing cover area wound up being slack in the timing chain and the camshaft would float and let the chain bump the timing cover. It sounded just like a lifter ticking just like your symptoms it ran fine. I ran it the rest of the summer and took the front off during the winter and there was a smile e face on the inside of the timing cover where it was rubbing.........I take that back it was a gear drive cam and it was the thrust washer worn down letting the cam float...

 

[Captain Gary]

Thanks for all the feedback. I figured a lifter slapping also. Thought the oil change and oil additive might take care of it but it didn’t. Then Figured they would diagnose and fix when they winterized. But they came back with the $10K rebuild. I think they’re trying to job me. Even a rebuild shouldn’t be that much. It’s hard to tell where it’s coming from other than it seems starboard side but doesn’t sound like deep in the engine but they said it was. Said they had to tear it down to find it then needed to do a full rebuild. Has Anybody tried a stethoscope to locate it? Might try that since if it’s a lifter I think that might work. Now I need to find a good and honest mechanic on the west shore of Lake Michigan. I’m done with skipper buds… again. Should have know better.

 

[B BARKER]

That's how I found mine is with a mechanics stethoscope and narrowed it down to the timing cover, my good friend is a mechanic and he helped me and he said I don't know what it is but it's something behind that timing cover !! If we hadn't used the stethoscope I would have bet my paycheck it was a lifter the way it sounded...