Volvo D6 310 Low Rev vibration

B

Bilbow

New Member
Joined
16 Apr 2013
Messages
14
Visit site
I have purchased a Nimbus 340 Commander with single volvo D6310. It all works fine but at revs below 1800 it has a small intermittent vibration which resonates with the mast and helm seat. It's not catastrophic but it is annoying, especially between 600 and 1100 which is important as I will be cruising rivers 50% of the time.
It's not engine mounts or below waterline exhaust.
I asked the guy who did the engine survey and didn't pick it up but he isn't answering. (He was more of a salesman for the broker rather than an engineer payed for by me! Should have gone with Volvo Paul!)
Does anyone have any insight?
 
Can you tell what it is that is vibrating?
Engine, or Shaft or Propellor out of balance?
Getting the Propellor balanced should be straightforward.
Shaft rather less so.
 
Does it do it in neutral ? Vibration is more likely shaft ( cutless bearing ) / prop. Is it fouled or clean ? Does pork have any damage ? There is always vibration on a boat to some extent
 
Do you have a rope cutter? Is it secured 100%?
I had this, the shaft was spinning and the cutter slipping causing vibration at a lower rev range.
 
If it ain’t the shaft / prop .which is where you need to look first , have you been in and scrubbed the prop .
Fouled props do remove previously smooth running motors
Different leaves foul at different rates depending on the stop position and the sun .
So the thing naturally becomes unbalanced parked at the dock .

Loose injector possibly. Extra heat up the rec range tightens it .?

similarly a loose exhaust manifold,- extra heat self seals and the prob vanishes at higher RPMs Not sure with marine if you would get other symptoms , depends on the design of the exhaust manifold??
 
Last edited:
Thank you for replies. Should have said...All obvious causes eliminated. Happens in neutral and in drive. Prop, shaft, exhaust eliminated.
Vibration is normal with a small extra wiggle every 5 seconds or so....its that which I need to eliminate...
 
Bilbow said:
I have purchased a Nimbus 340 Commander with single volvo D6310. It all works fine but at revs below 1800 it has a small intermittent vibration which resonates with the mast and helm seat. It's not catastrophic but it is annoying, especially between 600 and 1100 which is important as I will be cruising rivers 50% of the time.
It's not engine mounts or below waterline exhaust.
I asked the guy who did the engine survey and didn't pick it up but he isn't answering. (He was more of a salesman for the broker rather than an engineer payed for by me! Should have gone with Volvo Paul!)
Does anyone have any insight?
Click to expand...
Is this the Northney boat ?
 
Bilbow said:
Thank you for replies. Should have said...All obvious causes eliminated. Happens in neutral and in drive. Prop, shaft, exhaust eliminated.
Vibration is normal with a small extra wiggle every 5 seconds or so....its that which I need to eliminate...
Click to expand...

A friend at our a
marina had vibration proplems . The local engineers said props etc. They were on outdrives and were in pristine condition. He had it on both engines and when tried declutched the engines were not running as smoothly as they should, I suggested he get all his injectors serviced. He was a happy bunny next time I saw him.

You can easily test for this as I have said elsewhere. run the engine preferably on load and loosen the injector nuts one at a time listen and retighten. The cylinders where there is NO perceptible change in sound/performance when the fuel is being leaked may have faulty injectors. Just need a spanner and a roll of kitchen paper to soak up the spilled diesel which just dribbles oul of the nut.

This is worth a try.
 
Bilgediver said:
A friend at our a
marina had vibration proplems . The local engineers said props etc. They were on outdrives and were in pristine condition. He had it on both engines and when tried declutched the engines were not running as smoothly as they should, I suggested he get all his injectors serviced. He was a happy bunny next time I saw him.

You can easily test for this as I have said elsewhere. run the engine preferably on load and loosen the injector nuts one at a time listen and retighten. The cylinders where there is NO perceptible change in sound/performance when the fuel is being leaked may have faulty injectors. Just need a spanner and a roll of kitchen paper to soak up the spilled diesel which just dribbles oul of the nut.

This is worth a try.
Click to expand...
Do not try this it’s a common rail engine , you might just end up loosing an eye if you loosed the rail pipes when the engine is running .
This method is to test an older style engine with an injection pump.
 
volvopaul said:
Do not try this it’s a common rail engine , you might just end up loosing an eye if you loosed the rail pipes when the engine is running .
This method is to test an older style engine with an injection pump.
Click to expand...
Good point Paul. Does the engine panel give a fault indication if an injector goes open circuit?
 
It's not like it's running on 5...others have suggested an injector cleanup or some additive to the fuel. Is there any way to do some diagnosis without getting all 6 injectors out on the off-chance one is not behaving properly?
 
Paul commented that you have common rail fuel injection. Tis means that fuel supply to the engine is not controlled by the fuel pumps as in older engines but controlled electronically to deliver from a constant pressure source.. If it is an injection problem it may be electronic.
 
Thank you for your thoughts Bilgediver (love the name!) However I think that would bring up a fault code. There are no fault codes however...
 
Bilbow said:
Thank you for your thoughts Bilgediver (love the name!) However I think that would bring up a fault code. There are no fault codes however...
Click to expand...
Can you electrically disconnect a single injector (when stopped) and if you switch on without starting. Does a fault code come on. I was trying to get confirmation if the system would detect an open circuit.
Intermittent poor injection could cause similar problems to yours as caused by say a poor injector connection. I would suspect a fault code would appear but be nice to have confirmation.

Bilgediver has been around for quite some years. One copy cat in California also a marine engineer but navy.
 
Bilbow said:
It's not like it's running on 5...others have suggested an injector cleanup or some additive to the fuel. Is there any way to do some diagnosis without getting all 6 injectors out on the off-chance one is not behaving properly?
Click to expand...
Well you could get the rpms to simulate the vibration .
Then unplug ( if it’s possible) the electrical connection to shut down that cylinder .One at a time only momentarily.
The weak one ifs it’s one will have the least effect .

Then obviously clear all the codes and alarms this action is likely to trigger .
 
Portofino said:
Well you could get the rpms to simulate the vibration .
Then unplug ( if it’s possible) the electrical connection to shut down that cylinder .One at a time only momentarily.
The weak one ifs it’s one will have the least effect .

Then obviously clear all the codes and alarms this action is likely to trigger .
Click to expand...
That is what I had in mind. Shutting down one injector at a time. and listening. Is there accessible connections within the engine that can be easily reached?

Can you cut out one of the injectors using the OBD and a laptop?
 
Last edited:
No idea on that...don't want to generate fault codes that then get stored as its totally clean at the moment.
Does anyone with experience of the D6 have any ways I can diagnose?
 
There is a heap of speciation here recommending all sorts and faulty injectors now seems to rule the roost.

Get Volvo on board with a vodia tool. It is. It perfect but it will give a lot of infothat will help diagnose the issue rapidly and correctly.
 
True. I did hire a volvo engineer with the diagnostics but as I said at the beginning he didn't even mention or notice it...
We should be in discussions about it but he's not bothering to answer my emails...however there are no fault codes so maybe its just a "feature"
 
Bilbow said:
I have purchased a Nimbus 340 Commander with single volvo D6310. It all works fine but at revs below 1800 it has a small intermittent vibration which resonates with the mast and helm seat. It's not catastrophic but it is annoying, especially between 600 and 1100 which is important as I will be cruising rivers 50% of the time.
It's not engine mounts or below waterline exhaust.
I asked the guy who did the engine survey and didn't pick it up but he isn't answering. (He was more of a salesman for the broker rather than an engineer payed for by me! Should have gone with Volvo Paul!)
Does anyone have any insight?
Click to expand...
Is the vibration caused by a missfire? Could be an injector issue?
 
You must log in or register to reply here.

Share this page

Top