this case is just bugging me. how long has it been making the noise. generally, by the time you notice noise, it's been going on for a while. any gear or bearing making noise is gonna leave flakes in the oil like alien first mentioned. the oil will have a pearlescent sheen to it.
A break, I can't get.
- Thread starter mchad
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Just FYI, I won't be able to hear anything, as it's been fixed. See my previous post.
Charlie, about three weekends from when first noticed it. I didn't see the oil, but they said it was clean. I can't explain the missing shavings, but I didn't use the boat too much after first hearing it. All I know they said the driveshaft bearing has "chatter marks" - whatever the hell that means.
Sigh. Apparently it's not fixed. Went for a nice long ride, and when I pulled back in, same noise. I'm so very disappointed. So a $1000 repair bill that fixed... Nothing? I sent a new video of the sound to the marina owner, who responded with a "yep, I hear it. Let me think about it and put a plan together". So it's pretty clear it's not coming from the top half of the drive, as they disassembled it and saw no damage other then the "chatter marks" on the bearing, which was replaced. Just for good measure, replaced the u-joints and gimbal bearing as well.
And Charlie, they also checked the flappers which were replaced when the new motor was installed in April, and are good. So back to square one.
Like I said, I can't get a damn break.
And Charlie, they also checked the flappers which were replaced when the new motor was installed in April, and are good. So back to square one.
Like I said, I can't get a damn break.
at this point you're just gonna have to get a stethescope or hose and go over every bit of the drive and engine. the sound will travel because of all the metal components but listening carefully, you will be able to locate the exact point of the noise.
was the drive pulled and the bottom of the exhaust passages of the 'Y' pipe and in the drive exhaust passages inspected
these guys are making an awful lot of money off you
was the drive pulled and the bottom of the exhaust passages of the 'Y' pipe and in the drive exhaust passages inspected
these guys are making an awful lot of money off you
I have a scope. The problem is that the sound only happens when the the drive is hot - after say 10 min of planing. And it goes away after a few minutes of cooling down even at idle. At cold start it doesn't make a sound.
I can't reach the drive from the swim platform, so the boat will have to come out to test, as I'm not likely to jump in and stand next to a running motor/drive. So I have no idea how the hell I'm going to get it hot enough to make the noise, on land.
Also, the exhaust passage was clear - I looked up as far as I could when it was off. And besides, the flaps were inspected and intact.
And yes, I'm not thrilled to be paying for unnecessary repairs. Unfortunately I don't have the knowledge or equipment to do these kinds of repairs myself, so I'm stuck relying on the shop.
I suspect it's situations like these that make people give up on boating! (I'm not quite there yet, but it's frustrating as hell)
I can't reach the drive from the swim platform, so the boat will have to come out to test, as I'm not likely to jump in and stand next to a running motor/drive. So I have no idea how the hell I'm going to get it hot enough to make the noise, on land.
Also, the exhaust passage was clear - I looked up as far as I could when it was off. And besides, the flaps were inspected and intact.
And yes, I'm not thrilled to be paying for unnecessary repairs. Unfortunately I don't have the knowledge or equipment to do these kinds of repairs myself, so I'm stuck relying on the shop.
I suspect it's situations like these that make people give up on boating! (I'm not quite there yet, but it's frustrating as hell)
Today's plan: They discussed it, and are confident there's nothing wrong with the drive as they had it apart when they did the bearings. They want to pull the drive and put a Bravo 1 (that they have laying around) on it and have me go for a drive. That will tell if its the drive or something else.
Supposedly.
Maybe.
And just to add, call me silly, but I tend to trust this guy. He is one of the owners of my marina (family business), and they are genuinely good guys - always looking to save me a few bucks it seems. So I don't think I'm being hosed. Just saying.
Supposedly.
Maybe.
And just to add, call me silly, but I tend to trust this guy. He is one of the owners of my marina (family business), and they are genuinely good guys - always looking to save me a few bucks it seems. So I don't think I'm being hosed. Just saying.
it's just the 'replace while it's apart' syndrome. i really can't say it's wrong without seeing what the replaced parts look like. the age or last time the drive was taken apart all factor in. i've done it myself on personal toys. starting with a 'fresh' unit is a valid if not expensive reason.
get an oil sample out to a lab for analysis before you do anything. very inexpensive to do and if there is a bearing issue it will turn up in the report. absent corrosion or damage to the housing rebuilding outdrive is a good option if, the oil report comes back showing metal(s) in the oil. the type of metal and qty in the oil will tell what is going on.
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I've listened to that over and over and to me it just doesn't really sound like a noise from a rotating assembly, more like valve lifters, timing chain slack, tensioner, etc. I'd want to bend myself into the rear engine compartment and listen around there.
Going back to the tapping. Is it tapping in time to every rotation of the engine or every other rotation, as in time to the gear ratio of the drive.
The two possibilities I can come up with have to do with the cone clutch or loose end play on a shaft.
The two possibilities I can come up with have to do with the cone clutch or loose end play on a shaft.
Update: we pulled the drive, swapped with a bravo 1 the yard has laying around, same noise. Pulled that and ran it with no outdrive attached. Was told the noise was still there. That basically eliminates anything aft of the coupler. They poked around the engine with a stethoscope and heard it in the exhaust, and nowhere else. Opened a case with Mercury, who instructed them to remove the flappers, same noise still. When open, they checked the y pipe for any old flapper bits that may have been in there, but clear. Waiting for mercury's next instruction.
Well, I would have hoped that they would have found that with the stethoscope, but who knows. Really strange. You only hear it on the transom. It can be tapping away on the swim platform, but in the engine compartment, it's purring like a kitten. The motor sounds brand new - it is actually...
Injectors on an MPI can make a discernible tapping noise. If there is any chance that is the source, the scan device can likely disable 1 injector at a time on a power balance test to see if the tapping stops or changes.
Does the tapping definitely vary with RPMs? If so, can you tell whether it taps 1x/rpm or less often? That may be really difficult to discern.
I'd think they would have easily found a leaky ex.manifold gasket with the stethoscope if that were the case.
Blind dart throwing: since it seems to be "throwing it's voice" toward the transom & flappers are OK , remotely possibly 1 burned/weak exhaust valve? .
Does the tapping definitely vary with RPMs? If so, can you tell whether it taps 1x/rpm or less often? That may be really difficult to discern.
I'd think they would have easily found a leaky ex.manifold gasket with the stethoscope if that were the case.
Blind dart throwing: since it seems to be "throwing it's voice" toward the transom & flappers are OK , remotely possibly 1 burned/weak exhaust valve? .
OK, Some of the more odd things I've seen and forgot. Loose spark plug will tap. Loose flywheel or coupler. Loose rear motor mount(s). Loose transom assembly bolts. worn hinge or swivel pins in the bell housing. Loose or bad fitting gimbal bearing. and loose rear main bearing cap.
Here's a recording from yesterday. Got it hot (much more noticeable when its hot) and ran it from idle up to around 1800-1900 rpms then back down to idle. I can't count that fast, but it seems like its not 10 taps/sec - which would be 600 rpms. Seems more like 1 tap per 2 revolutions. But I can't be sure. So damn strange.
http://youtu.be/mvJnYlDvFDA
Sandy, you can't hear it at all in the engine compartment. Not one damn tap. That's what is making this so hard for them to diagnose. They said they heard it in the Y pipe, but that's it. I'd expect if it were a valve, you'd hear it in the manifold. Were it a bearing, you'd hear it in the bay next to the motor. But in the bay, its purring. It couldn't sound better actually. Driving me nuts.
*EDIT - I found an online metronome and set it at 600bpm, which sounds pretty damn close to it, so I'd have to say it is 1 tap/revolution...