KAD 44 - Limp Mode

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Dazzajohm

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Hi all,

Coming across the channel from Calais earlier today as it was a bit choppy thought I’d take some advice I’ve read on here previously.

Instead of running the engine with the supercharger on as it was too choppy to be going fast enough to be out side the range I thought I would disconnect it.

This resulted in what seems the boat going in to limp mode. I reconnected the supercharger but made no difference - the engine just would not do more than about 2,000 rpm.

When I got back to the marina I had a look and the charger belts do look like they’re spinning so that is obviously working.

Any ideas what this could be?

Cheers
 
try just underneath the black box - 2 x 7.5amp fuses one does the supercharger
the drive belts drive the s/c clutch pack all the time.
did you disconnect the s/c with the engine running?
 
VolvoPaul made it pretty clear that disconnecting the supercharger on KAD44 / KAD300 wasn't a good idea.
It might need a dealer with a Vodia tool to reset things.
 
So you were mid channel and decided to disconnect the supercharger in a single engined boat in choppy seas ?

Can I ask why ? I think you would struggle to find many on here that would shut an engine down off shore let alone tinker with it. Each to their own but unless you have done this before it seems most unwise - and even then you have compromised the engine as Volvo added a supercharger for a reason.
 
kashurst said:
try just underneath the black box - 2 x 7.5amp fuses one does the supercharger
the drive belts drive the s/c clutch pack all the time.
did you disconnect the s/c with the engine running?
Click to expand...

Great thanks will have a look when I get down later. Convinced it’s got to Be something simple.

No I didn’t disconnect / reconnect with the engine running. I stopped it
 
jrudge said:
So you were mid channel and decided to disconnect the supercharger in a single engined boat in choppy seas ?

Can I ask why ? I think you would struggle to find many on here that would shut an engine down off shore let alone tinker with it. Each to their own but unless you have done this before it seems most unwise - and even then you have compromised the engine as Volvo added a supercharger for a reason.
Click to expand...

We wasn’t exactly mid channel we were literally just off the French coast actually.

I’m sure you will be aware there are many post on this forum about whether it’s ok to run the engine with the s/c on constantly or not. I’ve been told by a VP dealer not to and in situations such as this to just disconnect the charger. I was also told that it may be worth getting a switch installed to do this easier without having to go in the engine bay at sea.

Any decision is about weighing things up and as I’ve not been exactly lucky with my engine I didn’t want to run the risk of knackering up my s/c by running it for two hours across the channel and the 10 seconds it took to turn engine off, open the engine hatch and quickly reach in to disconnect the plug I don’t belive was much hassle!
 
"I’m sure you will be aware there are many post on this forum about whether it’s ok to run the engine with the s/c on constantly or not. I’ve been told by a VP dealer not to and in situations such as this to just disconnect the charger. I was also told that it may be worth getting a switch installed to do this easier without having to go in the engine bay at sea. "

the kad 44/300 won't run properly with the s/c disconnected. It's another myth passed on from the kad 42/43 which will run with the s/c disconnected as they are not electronically controlled. However its a bad idea to disconnect the s/c on a kad 42/43 as the engine will potentially be over-fueling. Probably OK if just pootling, but doing it with any load on the engine could be a seriously bad idea.

I also don't understand this thing about not running the engine with the supercharger engaged for long periods of time (as in hours). I suspect this is another myth that has been propagated as a result of issues with early kad 42 etcs, and has become the perceived wisdom on how to treat all kad series engines.
Lots of engines use s/c's permanently engaged and the clutch is a car air-con clutch designed to be engaged/on for hours at a time.
The only mention in the volvo user manual I can find, is to avoid running the engine at 1000 rpm and 2800 rpm which is the two points where the s/c clutch engages and then disengages. Which makes sense as the clutch will be going on and off and will wear it out.

If you could only use the engine from 600 to 900 rpm and then only from 2900 to 3800 rpm it would be unsaleable and Volvo's warranty claims would be catastrophic because people would run the engine with the s/c engaged anyway. I haven't seen any thread so far warning people not to run a D6 350 engine with the supercharger engaged, its essentially the same idea as a kad 44/300.

I would find a different VP dealer.
 
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FlowerPower said:
VolvoPaul made it pretty clear that disconnecting the supercharger on KAD44 / KAD300 wasn't a good idea.
It might need a dealer with a Vodia tool to reset things.
Click to expand...

Yes I’m aware that was his opinion just as it was his opinion a while ago that a hand made gasket I got fabricated for my rocker cover would not work but in fact it actually worked perfectly and has remained working.

The fact remains on this topic that there is a difference of opinion on this
 
Thanks to those with the constructive suggestions. As suspected was only something simple and the fuse reset buttons on the back of the black box fixed the problem.
 
kashurst said:
"I’m sure you will be aware there are many post on this forum about whether it’s ok to run the engine with the s/c on constantly or not. I’ve been told by a VP dealer not to and in situations such as this to just disconnect the charger. I was also told that it may be worth getting a switch installed to do this easier without having to go in the engine bay at sea. "

the kad 44/300 won't run properly with the s/c disconnected. It's another myth passed on from the kad 42/43 which will run with the s/c disconnected as they are not electronically controlled. However its a bad idea to disconnect the s/c on a kad 42/43 as the engine will potentially be over-fueling. Probably OK if just pootling, but doing it with any load on the engine could be a seriously bad idea.

I also don't understand this thing about not running the engine with the supercharger engaged for long periods of time (as in hours). I suspect this is another myth that has been propagated as a result of issues with early kad 42 etcs, and has become the perceived wisdom on how to treat all kad series engines.
Lots of engines use s/c's permanently engaged and the clutch is a car air-con clutch designed to be engaged/on for hours at a time.
The only mention in the volvo user manual I can find, is to avoid running the engine at 1000 rpm and 2800 rpm which is the two points where the s/c clutch engages and then disengages. Which makes sense as the clutch will be going on and off and will wear it out.

If you could only use the engine from 600 to 900 rpm and then only from 2900 to 3800 rpm it would be unsaleable and Volvo's warranty claims would be catastrophic because people would run the engine with the s/c engaged anyway. I haven't seen any thread so far warning people not to run a D6 350 engine with the supercharger engaged, its essentially the same idea as a kad 44/300.

I would find a different VP dealer.
Click to expand...


Hi Kas,

Yes I think next time I will leave well alone. I guess after some bad luck with my engine and it now finally seemingly on track I thought I would disconnect just in case as otherwise would have meant me running in the s/c range for the whole passage of about two hours and I was paranoid it would blow up!

I've spent quite some time doing reasearch in to this topic and it seems very split between you can / can't run in the s/c range. I've even spoken to different Volvo dealers with different opinions so it seems even they can't agree.

On one hand logic tells you as you mention above that if you couldn't operate in the s/c range the engine is pretty useless but then once other hand why are so many people fitting bypass switches etc?

Think I've learnt my lesson this time though and I'll leave well alone in future ?

On previous posts on here I've read about people who have fitted switches so they can disengage the s/c if they are required to run at a speed which would mean it was permanently engaged.
 
I ,am almost sure in the kad 300 manual ( when I had one ) it said don,t run with constant SC .
It’s designed for short bursts periods to get the boat up thereby the turbo takes over ,which is designed for constant running .
The KAD 300 and it predecessors are for high speed planing leisure boats .

It’s not the clutch in out thing that’s obviously gonna wear the clutch keeping it @ 1400 or 2600 .
It’s nowt to do with Merc Komoressors etc .
You are basically overheating the thing both sides of the gear seals .
One side is the oil lubed twin gearbox that the clutch attaches , other side is dry vanes that compress the air .Get those hot for long and you wear away the thight metal fit as they expand a fraction to touch .

The Vp SC is meant to be temporary only in operation 20-30 sec etc -anoying in terms of a no go area for cruise .
Whine btw is the dry airside rotators touching - go figure
 
Portofino said:
I ,am almost sure in the kad 300 manual ( when I had one ) it said don,t run with constant SC .
It’s designed for short bursts periods to get the boat up thereby the turbo takes over ,which is designed for constant running .
The KAD 300 and it predecessors are for high speed planing leisure boats .
Click to expand...

Porto, I've checked and the KAD44/KAD300 manual doesn't make any such recommendation.

Here is the most recent thread on the topic...

http://www.ybw.com/forums/showthread.php?503202-KAD-44-Supercharger

Note volvopaul's comment ... !

No it won’t it will place the engine into limp mode and throw up a fault code.
Click to expand...
 
Volvo Penta have been building engines since 1907, they have made millions of engines and have a huge knowledge base from all the things people will do to use and abuse their engines - I am very confident they know what they are doing. If they thought it was a good design solution to give the operator a switch to disable the supercharger they would have provided one. They didn't! that tells you all you need to know.
If any one is not sure what they can/cannot do with their engine - just download and read the official Volvo user manual carefully and thoroughly. Stay well away from many of the USA based boat forums - some of the stuff posted there defies belief and is repeatedly held up as "scientific fact".

PS This afternoon I have run my KAMD 300s for 30 minutes at 1200 rpm - guess what,
the belts all snapped?
the engine started spouting steam and black smoke?
the s/c clutch overheated and caught fire?
the superchargers overheated and all the paint fell off?
all the fuses blew and the relays evaporated?
no........

they work perfectly! edit - after 12 months and nearly 70 hours with new volvo belts there is hardly any black belt dust either.
 
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Portofino said:
I ,am almost sure in the kad 300 manual ( when I had one ) it said don,t run with constant SC .
It’s designed for short bursts periods to get the boat up thereby the turbo takes over ,which is designed for constant running .
The KAD 300 and it predecessors are for high speed planing leisure boats .

It’s not the clutch in out thing that’s obviously gonna wear the clutch keeping it @ 1400 or 2600 .
It’s nowt to do with Merc Komoressors etc .
You are basically overheating the thing both sides of the gear seals .
One side is the oil lubed twin gearbox that the clutch attaches , other side is dry vanes that compress the air .Get those hot for long and you wear away the thight metal fit as they expand a fraction to touch .

The Vp SC is meant to be temporary only in operation 20-30 sec etc -anoying in terms of a no go area for cruise .
Whine btw is the dry airside rotators touching - go figure
Click to expand...

I doubt Volvo manufacture the super chargers, just like they don't manufacture turbo chargers.

If what you say is true, there would be no such thing as a permanently supercharged car because they would fail every few thousand miles for being in continuous operation...
 
You’d hear a very distinctive and unpleasant noise if those supercharger vanes ever made physical contact.
Kind of like a food blender full of marbles.
 
I can't help thinking if the engine goes into limp mode if you unplug the supercharger, it would be perfectly capable of going into limp mode if you were to overheat the supercharger through overuse - in other words I would just use the engine and not worry about it.
 
petem said:
Porto, I've checked and the KAD44/KAD300 manual doesn't make any such recommendation.

Here is the most recent thread on the topic...

http://www.ybw.com/forums/showthread.php?503202-KAD-44-Supercharger

Note volvopaul's comment ... !
Click to expand...

It’s a Swedish to Eng translation the book .
Some things are lost in the syntax
It says you run irrc 3000, 3200 or the arbitrary “10% less WOT “
This is what it recommends .
We need a copy of it posted for all to see .Over to you Peter ?
It tells you the function of the SC ,s and I,am sure suggests don,t hover in that zone if you don,t need to or words to that effect .

It’s not the same as a Merc Kompressor or any other auto part , that you all seem to be clinging on to in the belief it’s ok to run it constantly ad infinitum.
It’s origin is irrelevant, it’s it use and designer / engineers intention that you need to know .
“ High speed planing craft “

Let’s face it VP bolt on parts ( wether in house or bought in ) are not famous for longevity,

Btw give me an example in the auto world of a superchrger ( to get going ) and the turbo that takes over once above a rev range ?
 
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