High pitched noise / cold startup

Boat/engine is a 2003 SAN / PCM Excalibur with two belts (non-serpentine)

Part of me wants to just say, IT'S BELT NOISE DUMMY but I feel like it may not be in this case. When I first start up the engine cold, I hear a high pitched, somewhat irregular squeak from the engine. It's not quite as rhythmic as I would expect for a belt sound, nor is is constant. It's frequency is slower than the rotation of the belts, for sure. And it really sounds like a pulley bearing, less than a belt noise.

In any case, I've ordered new belts because a) they're cheap and b) I'm not sure when they were changed last, but I don't believe this is the likely cuplrit.

I guess my question is, since this engine doesn't have the serpentine belt, it doesn't have any idler pulleys or tensioner pulleys, right? I'm curious if any other rotating parts are prone to bearing issues, or if I'll just have to narrow it down by listening with a dowel or something...

When I take the belts off I'll try running it momentarily with each belt off (one at a time) which should also narrow it down...

The sound goes away when the engine is warm, which is another reason for me to think it's not just a belt. If that's the case, I'd like to address it before it becomes a real problem.

You have two water pumps with bearings and an alternator with bearings.

I like your narrowing it down approach running it with each belt off for a short time to see if the noise goes away.

KENO wrote: You have two water pumps with bearings and an alternator with bearings. I like your narrowing it down approach running it with each belt off for a short time to see if the noise goes away.

The previous owner put a new RWP in it - not just the impeller, but a whole pump. So, while it's unlikely to be that, I also know that part has recently been changed.

I believe the boat to have around 500-600 hours. I found what I am sure is the same boat, listed on onlyinboards last spring with 495 hours. The guy I bought it from said after a tach gauge replacement, the hour meter for some reason now says 3,800 + hours. This boat doesn't have 3,800 hours on it, based on lack of wear and tear on everything I can see and feel. In any case, I'm not sure of the exact hours, unfortunately. Why the bearings failed in the old RWP, I don't know.

My point of all this hour talk is that it's *possible* there are a lot more than 500 hours on the engine; if the RWP failed last year, then maybe something else is similarly worn. But I know I had well over 1,000 hours on my old GT-40 sherwood water pump with no issues.

Don't forget the other water pump that nobody ever pays any attention to

KENO wrote: Don't forget the other water pump that nobody ever pays any attention to

That's the first item I'd look at. For some reason, circ pumps are notorious for bearings going. Yes, it does seem nobody pays attention to them until they start leaking.

Morgan,
Until the bearing gets to the point where there's axial ply, the seal will still hold.

Keep It Simple, Stupid. Right?

Last night I finally got around to looking into this. I took off the RWP belt and the noise was basically gone. Hmm. I took off the alternator belt and put the RWP belt back on, still no noise. Strange, but ok? The difference was I didn't fully tension the belt. So... I can only say that when I took it apart, the RWP belt seemed extremely tight, maybe it really was belt noise? It doesn't seem likely that a bearing would make noise from an over-tightened belt, but it's possible I suppose.

For those who aren't familiar with the two-belt Excaliburs, the RWP has its own belt and it's very short, but the pump is mounted to a nice big flat bracket with a 1/2" square hole machined into it. This is so you can put a 1/2" ratchet in there and use that for leverage to tension the belt. The only problem is, someone could pretty easily tighten it way up, more than is necessary in my opinion.

In any case, with two new belts, I didn't hear the squeaking sound. The engine wasn't dead cold, though, by the time I started it and stopped it a handful of times in my testing. So next cold startup will really tell the tale, but I'm cautiously optimistic it could have just been belt noise. It was too easy to change out the belts not to try that first, not knowing the age of them anyway.