Volvo Penta D1-30 29hp vibrating in neutral, normal?

[Sirfloatsalot]

Hi All,

Long time reader, first time poster.

I am very close to putting in an offer on a 36ft Westerly, fitted with a 2017 Volvo Penta D1-30 29hp inboard diesel engine.

Please see video but in neutral she seems to shake/vibrate/move a lot... or is this normal? A mounts issue perhaps? Or nothing to worry about?

Goes into neutral at 10 second point: https://youtu.be/KFhTAtPPQxU

Thanks for any help!

[tkeithlu]

Welcome to the forum, Sir.

That's too much vibration, particularly in gear. The engine sounds OK, but something is not aligned correctly (or aligned, period) in the drive train. Or, it's unbalanced. Could be the prop, could the the shaft alignment, but whatever it is, yeah.

[jimbunyard]

Definitely something wrong; you can hear the rhythmic clunking when it's in gear.

Doubt it's a mount, though it could be. Start with simple things, check for fouled or dirty prop, loose flange bolts, etc. That it seems to perform normally out of gear is indicative that the problem is most likely in the drive train.

[Sirfloatsalot]

Thanks a lot for the help!

On the listing it says "New gearbox coupling to propshaft and new support bracket fitted 2019" so I wonder if maybe this has not been installed/aligned properly?

[jimbunyard]

Could be, though a lot can happen in two years. Again, I'd check first for obvious problems like loose fasteners and physical problems like a heavily fouled prop (barnacle encrustation can certainly throw a prop way out of balance) or even something as simple as debris wrapped around the prop or shaft.

If by 'support bracket' the OE means 'shaft strut' I'd be asking "What happened", and inquire if the shaft was checked as well. When fitting a new coupling to a shaft, it is imperative that the shaft and coupling are correctly aligned, with the coupling face as close to perpendicular to the long axis of the shaft as possible.

[marcjsmith]

if its heavily vibrating in neutral. that Should take the prop/shaft/coupler out of the equation. leaving trans/engine.


I'm not mechanic, nor did I sleep at a holiday inn last night. But it really looks like the motor is on the verge of stalling. Ie that the idle is set to low and its barely getting enough fuel to fire, Whats the idle RPM


here is thread on the forum about the d130 and the shaky motor
https://www.cruisersforum.com/forums...gh-233540.html

[tkeithlu]

Marc has made a good point. There is another possibility other than an inbalance. But then, it should decrease as engine RPM goes up and the engine runs smoothly.

Thinking back on the video, I'm also surprised that the engine mounts allow the engine to shake that much.

You've got some exploring to do. Good luck with it.

[jimbunyard]

Except that the motor doesn't shake when it's out of gear. Watch and, more importantly, listen to the video again. At about 7.5 seconds, the motor goes from a smooth, regular proper idle to a shaky, stumbling idle (with little apparent loss of rpm, indicating an engine in otherwise good shape) as soon as it is put into gear, and simultaneously a very noticeable, rhythmic clunk, clunk, clunk, clunk, clunk also begins.

If y'all still dont hear it, slow the video down to .25 playback speed and listen again. The difference is very obvious.


I am a mechanic, though obscure statements about overnight accomodations often fly directly over my head...

[Sirfloatsalot]

Thanks again all, i've enquired about any known incidents that would have caused the "bracket" to be installed/replaced, will let you know...

Just to clarify, and excuse my engine naiveté, I am truly a novice, but the engine was started with the lever in forward position then around 7.5 seconds I asked to see it in neutral which is when the shaking starts.

Unfortunately I don't know the RPM

[marcjsmith]

Originally Posted by jimbunyard

E
I am a mechanic, though obscure statements about overnight accomodations often fly directly over my head...

Jim. If you read the ops initial post. It starts shaking after it goes into neutral. It seems that the shaft and prop when spinning help smooth out some of the vibration.

Holiday did a commercial. If I explain its just not as funny.

[jimbunyard]

Well that changes everything...though I'd verify that the engine was started in gear and that the shaking started after putting it into neutral. Most modern boats have a device that prohibits the engine from starting in gear. But they're easily and relatively often bypassed...

The shaking in your video resembles the shaking in the subsequently referenced videos very little; whilst that problem was not indicative of a real issue, the 'shaky-ness' demonstrated in your video is.


Marc, well that explains it. I'm a mechanic who doesn't own a TV and has adblocker installed on my PC.

[Sirfloatsalot]

Agreed. That previously referenced forum thread which i'd read before posting myself seems to have significantly less shake, by a long margin...

Still could be a fouled prop, loose fasteners etc as you say. Will see what the broker comes back with...

It was definitively started in gear - it stuck in my head because i'd not seen that done before.

Thanks again

[Searles]

First ,check idle speed needs to be around 825 rpm no load I e out of gear check shaft by turning by hand ,feel for tightness ,also check engine mounts are actually firmly bolted down , good luck

[sinnerman]

If idele speed is checked to be OK, then look for a dirty / leaking injector

[Gypsy23]

Originally Posted by Sirfloatsalot

Hi All,

Long time reader, first time poster.

I am very close to putting in an offer on a 36ft Westerly, fitted with a 2017 Volvo Penta D1-30 29hp inboard diesel engine.

Please see video but in neutral she seems to shake/vibrate/move a lot... or is this normal? A mounts issue perhaps? Or nothing to worry about?

Goes into neutral at 10 second point: https://youtu.be/KFhTAtPPQxU

Thanks for any help!

Excuse me for doubting your description of what happened....but...from what I see in the first few seconds of the video it is running smoothly as if in idle/neutral. Then when the change occurs the revs drop and the motor vibrates badly.....it certainly looks like it goes into gear, puts a load on the motor to drop the revs then shakes because of some imbalance in the prop, shaft etc.


OP needs to confirm whether the shaft is rotating when the shaking occurs, or not.