High pitched noise / cold startup
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Engine Repair
Forum Discription: Engine problems and solutions
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=41572
Printed Date: October-06-2024 at 10:23pm
Topic: High pitched noise / cold startup
Posted By: stepper459
Subject: High pitched noise / cold startup
Date Posted: July-21-2017 at 11:23am
|
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. |
Replies:
Posted By: Duane in Indy
Date Posted: July-21-2017 at 11:33am
"Something" meaning a Harbor Freight stethoscope. Dowels around moving parts tend to get very dangerous..  ------------- Keep it as original as YOU want it 1978 Mustang (modified) |
stepper459 wrote:Posted By: KENO
Date Posted: July-21-2017 at 12:14pm
|
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. |
Posted By: stepper459
Date Posted: July-21-2017 at 12:35pm
True; I have used all kinds of different things for this purpose... it's mostly a matter of being very careful. A mechanical stethoscope is way better than a dowel, maybe it's time to "invest" in one. Years working at a marina I was spoiled by having access to nearly unlimited tools all the time. Now, I have to beg/borrow/steal or "invest" |
Posted By: stepper459
Date Posted: July-21-2017 at 12:42pm
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. |
Posted By: Dreaming
Date Posted: July-21-2017 at 1:12pm
| alternator would be worth checking, those can get loose internally if the belts were too tight and caused more strain than necessary on the internal bearings or case. worth looking at. Hours could be a result of leaving the switch on and accumulating time, they may have had the battery on a tender, and just left the all on switch active... 3800 hrs is a lot of battery drain, but 3800 hr boats (like camp boats) have had a couple of engines and are pretty raggedy usually. I too suspect that boat has significantly less hrs. than the meter shows |
Posted By: KENO
Date Posted: July-21-2017 at 1:48pm
| Don't forget the other water pump that nobody ever pays any attention to |
Posted By: stepper459
Date Posted: July-21-2017 at 1:52pm
|
Good thought on the belts being too tight - alternator would be a pretty easy swap out, if that were it. I will miss my old DD when it comes to access, though haha. Quick math of 3800 / 24 = 158.33 - that's a lot of days to leave the switch on with a tender, but it's definitely possible. I have seen other instances of gauges showing some absurd number after replacement. Almost like they want to default to a high number so you can't just buy a new gauge and claim low hours? I believe the Perfect Pass may have hours stored, too, but also that any user can modify that number, so it might be useless. I may try to get my friends at the marina to hook up a scan tool to the engine, I understand the GM based engines can have hours stored in the ECU, if you have the right scanner. They're PCM certified and I used to be the one to update the software on all our scan tools so I'm sure they have the equipment. I just feel bad going there on a weekend which is the only real time I have! Imagine that. |
Posted By: 8122pbrainard
Date Posted: July-21-2017 at 4:11pm
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. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: stepper459
Date Posted: July-21-2017 at 4:28pm
If the circ pump bearing was going, wouldn't it leak water? I'm not saying mine isn't leaking... to be honest I haven't checked carefully. But it should leave evidence, and/or be visibly wet from a leak while running. Unless the issue is too small to leak water just yet... it does quiet down when things warm up. |
Posted By: 8122pbrainard
Date Posted: July-21-2017 at 4:35pm
|
Morgan, Until the bearing gets to the point where there's axial ply, the seal will still hold. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: stepper459
Date Posted: July-21-2017 at 4:45pm
Pete, Thanks for the advice, it's people like you that got me back on this forum. Planet Nautique is great too, for different reasons. I've learned a lot over the years from reading posts by you and others. I'll keep this updated as I work toward a resolution. Cheers, Morgan |
Posted By: stepper459
Date Posted: August-01-2017 at 12:41pm
|
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. |