KAD 300 help please

Al Dickson

Al Dickson

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Coming home last weekend, The starboard engine on my Botnia Targa 35 has decided it wont rev above 3000rpm.

If I set the engines to approx 2800rpm te revs fluctuate / pulsate between 2800 and 2900 - you can see it on the rev counter and hear the engine note change.

They have done 750 hours and were serviced about 40 hours ago - the engine sounds fine and there is no smoke, temps are normal, oil pressure is good.

We checked the primary filter which was a bit black - we recently dosed the tanks and I have been told the black could be dead bug - however fitting a new filter made no differrence.

Both engines run off the same tank and the Port one is running perfectly

An ideas ?

Thanks

Alan
 
Could be the port engine has lost one of it's props and the starboard is having to work harder. I've sheparded a boat back from the CI which thought it had a dodgy engine only to find the front prop had fallen off the 'good' engine.
 
I will go down & check the props tonight - guess I had assumed would feel some vibration if there was a problem with one of them

I have tried run the boat on each engine individually and it doesn't change the characteristics.

The only other thing which has been a prob for a week or so is the leg on the "good" Port engine can be slow to engage gear which I presume is a different issue

Sometimes it takes a few seconds and occasionally it doesn't engage at all - in fact an hour before we noticed the problem with the engine - we were motoring out of an anchorage slowly then as we gradually powered up the engines the port leg engaged at approx 1800 rpm with a bit of a bang. According to my engineer there is no adjustment left on the cable so we will need to pull her out to adjust the leg.


Alan
 
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Just a thought but, considering the issue with engaging gear, could it be the clutch slipping under power/load ??

Paul
 
OK have checked the props, hoses and replaced all the filters but made no differrence.

Took it out for a run this morning and there is definitely a problem with the starboard supercharger cutting in and out between 2500 and 3000 rpm causing the revs to rise and fall.

If you accelerate right up through the rev range its fine but if you try to accelerate between 2500 & 3000 rpm she gets stuck at between 2600 - 3000 rpm (varies each time) and the falling & surging starts again.

We are thinking theres a sensor gone on the blink or some electronic glitch - either way a call has been put in to the Volvo dealers who apparently have the technology to interrogate the ECU.
 
Eastbrae said:
OK have checked the props, hoses and replaced all the filters but made no differrence.

Took it out for a run this morning and there is definitely a problem with the starboard supercharger cutting in and out between 2500 and 3000 rpm causing the revs to rise and fall.

If you accelerate right up through the rev range its fine but if you try to accelerate between 2500 & 3000 rpm she gets stuck at between 2600 - 3000 rpm (varies each time) and the falling & surging starts again.

We are thinking theres a sensor gone on the blink or some electronic glitch - either way a call has been put in to the Volvo dealers who apparently have the technology to interrogate the ECU.
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I know the engines are sync'd, but do both engine revs rise and fall by the same amount, or does the s/board one move about on its own, and end up at a different revs? And its not occasional, but permanent, it seems?
Curious to know what Volvo say.
 
The starboard one moves up & down on its own - Port engine running fine

We have an = button to sync them, really only works if they are 100 or so RPM apart

but pushing it makes no difference to the probelm

Will keep you posted

Alan
 
Sounds very much like a worn turbo to me. Remove the exhaust elbow from the turbo and check the gap between the blades and the housing. Any more than 1 or 2 mm and this will cause the supercharger to cut in and out.
 
Ive has the same

Eastbrae said:
Coming home last weekend, The starboard engine on my Botnia Targa 35 has decided it wont rev above 3000rpm.

If I set the engines to approx 2800rpm te revs fluctuate / pulsate between 2800 and 2900 - you can see it on the rev counter and hear the engine note change.

They have done 750 hours and were serviced about 40 hours ago - the engine sounds fine and there is no smoke, temps are normal, oil pressure is good.

We checked the primary filter which was a bit black - we recently dosed the tanks and I have been told the black could be dead bug - however fitting a new filter made no differrence.

Both engines run off the same tank and the Port one is running perfectly

An ideas ?

Thanks

Alan
Click to expand...

I have experienced just what you are going through. If you get past the 2800 2900 band it will go away.

I had a Volvo engineer on board who had the Vodia tool plugged in while we went out on sea trial. Found absolutely nothing wrong, all was working normally, swapped the engine ECU's to see if the problem moved, but no difference.

Got back and lifted the boat, cleaned the bottom, and went out again. Problem seemed to have gone.

Engineers conclusion was that the dirty bottom was stopping the boat get up and plane efficiently, therefore holding on the cusp of the supercharger being in and out hence the pulsing.

All this said I still have a leaning to others opinions that there is a turbo wear issue, which seems to make sense to me. incidentally my engines have done around 900 hours albeit in a heavier boat

Neil
 
Took it out for a run this morning and there is definitely a problem with the starboard supercharger cutting in and out between 2500 and 3000 rpm causing the revs to rise and fall.
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Does sound like an electronic fault on the supercharger. I believe they are only supposed to run between 1500 and 2500rpm.

Could it be the gate between the supercharger and turbo getting stuck or lazy?
 
Moody said:
I have experienced just what you are going through. If you get past the 2800 2900 band it will go away.

I had a Volvo engineer on board who had the Vodia tool plugged in while we went out on sea trial. Found absolutely nothing wrong, all was working normally, swapped the engine ECU's to see if the problem moved, but no difference.

Got back and lifted the boat, cleaned the bottom, and went out again. Problem seemed to have gone.

Engineers conclusion was that the dirty bottom was stopping the boat get up and plane efficiently, therefore holding on the cusp of the supercharger being in and out hence the pulsing.

All this said I still have a leaning to others opinions that there is a turbo wear issue, which seems to make sense to me. incidentally my engines have done around 900 hours albeit in a heavier boat

Neil
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Thanks for this Neil - the Targas plane at very low speeds, in fact the hull creates so little hump its hard to tell the point she actually hops up - probably only at about 10 knots - but then she only weighs about 8.5 tonnes

At 2500rpm we are already planing along at about 20 knots - and actually if I floor the throttls she will still accelerate (more slowly) up to top speed 32 knots even with the Starboard engine stuck at 3000rpm !

My prevous boat (Nordstar 31) needed a bloody great shove on the engines to get her up then backing off on the throttles or we would be into 35 + knots - so I could see where that would be a problem as you describe it !

I will check the Turbo tonight
 
Hi

An interesting post.

Have you tried the throttle without any load to see if the problem is still there?

I can understand people saying check the turbo but I not sure on that one at the moment. I can't help thinking the leg problem might be the culprit here.

For info the supercharger should be cutting out at 2600+/-50rpm

As always please keep us all up to date as we all learn from these situations.
 
Does the KAD300 have an electromagnetic clutch the same as the KAD32. If so these can be prone to slipping or getting stuck on/off (by all accounts. We have had no trouble with ours yet at 740 hours <touches wood>). Would this give the symptoms found in this case?
 
Unfortunately the EDC will only allow me to rev the engines to about 1500rpm in neutral.

As far as I know the superchargers have EM clutches - the sensor is obviously pulling the SC back in when the revs go below 2800rpm so question is whats making the revs fall away in the first place ?

And why when I try to accelerate from this area of the rev range does the engine want to give up about 3000 - even although it will rev way past that if I slow the boat down below 1500 rpm and then accelerate through that rev band without pausing ?

Will keep you informed of developments - at the moment we are working on trail and error !

A
 
Hi

Please do not confused with what is controlling the supercharger, it is not the EDC but the speed relay.

Just so you know what rpm's things should be happening at, on a KAD the SC cuts in at 1700rpm and out at 2600+/-50rpm.

Sorry I forgot the EDC won't allow you to open up out of gear.
 
Its sorted !

The man from Macdonalds Power plugged in his Vodia and declared the air inlet temp sensor was faulty - reading 55 degrees c and automatically putting the engine onto limp mode - they changed the sensor and we are sorted - well done lads !

Thanks for all the suggestions

Alan
 
Eastbrae said:
The man from Macdonalds Power plugged in his Vodia and declared the air inlet temp sensor was faulty - reading 55 degrees c and automatically putting the engine onto limp mode - they changed the sensor and we are sorted - well done lads !

Thanks for all the suggestions

Alan
Click to expand...

Wow, thats one to save !
 
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