kad 42 both engines overhheating

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captaindan

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Hi all

having some overheating problems wth a set of kad 42 volvo engines

so popped out today on the boat today and within 5 minutes both engines overheated turned them off straight away waited for them to cool down which took ages. decided to abort the trip and just anchored up just outside the marina. so boat had been left maybe 6 hours before staring back up thought i would give it a quick run to see what it would do same again with in about a minute it started to overheat. however when i was looking at the battery dials they were showing at 10 volts. (brand new fully charged batteries which one separate from the domestic) I am now wondering if it could be a electrical problem as i find it hard to believe that an engine could overheat so quickly straight way and both of them at the same time. the last time i took it out she was running sweet 3 weeks ago as had heat exchangers done etc on the last annual service

I did think it might be a thermostat problem but in both engines at the same time seems strange any helpful suggestions on a postcard please

regards

Danny
 
captaindan said:
Hi all

having some overheating problems wth a set of kad 42 volvo engines

so popped out today on the boat today and within 5 minutes both engines overheated turned them off straight away waited for them to cool down which took ages. decided to abort the trip and just anchored up just outside the marina. so boat had been left maybe 6 hours before staring back up thought i would give it a quick run to see what it would do same again with in about a minute it started to overheat. however when i was looking at the battery dials they were showing at 10 volts. (brand new fully charged batteries which one separate from the domestic) I am now wondering if it could be a electrical problem as i find it hard to believe that an engine could overheat so quickly straight way and both of them at the same time. the last time i took it out she was running sweet 3 weeks ago as had heat exchangers done etc on the last annual service

I did think it might be a thermostat problem but in both engines at the same time seems strange any helpful suggestions on a postcard please

regards

Danny
Click to expand...

Hi, 5 minutes to overheat is a bit quick but if the engines were working hard, not unreasonable. I would not assume thermostats. Given that the problem is on both engines that were working perfectly until recently i would be looking at what has changed, For instance, you said you have recently had the heat exchangers done and new batteries. Have the engines worked correctly since that work or has that work caused the problem. Is the cooling water coming out of the exhausts? If it is, maybe the overheat alarm is lying. Did you check both seawater filters recently? If they are the VP ones with the black screw caps they are notoriously difficult to get a good seal on the lids which results in the seawater pumps not self priming and the engine overheating due to a shredded impeller. Also, if the engine start batteries are showing only 10 volts i am surprised they will start the engines. Hope these thoughts help.

Www.solocoastalsailing.co.uk
 
If an overheat is indicated it is worth checking the front plate on water pump (brass cover over the impeller) - if it is cold it means raw water is circulating and if it is then better to let them run at low revs as that will help them cool quicker. Shutting them down is a little more risky as I understand it as there is nothing to help them cool.

Thinking about basics, have you checked the raw water filters? Also, those engines the raw water pumps don't always self-prime so if the brass plate is hot then it may be that raw water is not circulating. Solution is to crack open the raw water filter lids while the engines are running, just enough until some water seeps our and then re-tighten. Check the brass plate again and if it is cold probably problem solved. We had KAD 42s in our last boat and always checked the water pump plates when first starting up after the boat had been out of the water or left for a while.
 
Last edited:
okay
thanks for that

there has been some developments, I had checked the water intake on the drives to see if they were blocked on that end and have found that one of the duo prop starboard has chunks out of it I think this was caused by a rope that caught itself round the prop from a mooring line in the marina (boat is in the med)last time we used it. wondering if the damage to it is enough to make the engine work harder and overheat it and perhaps the other engine also (there are three chips out of the leaves about an inch big

do you think this may be a contributing factor.

going to run them up this morning and check sea strainers and impellor housing like you suggest as a process of ilimination.

thanking you for your advice

regards

Danny
 
I'd take an IR temp gauge with you to see if they are really overheating as a first step, especially if the alarms didn't go off also.....or did they?
Then you know if electrical or really a cooling problem.
Wouldn't think your prop issue is the problem.
 
dpb said:
I'd take an IR temp gauge with you to see if they are really overheating as a first step, especially if the alarms didn't go off also.....or did they?
Then you know if electrical or really a cooling problem.
Wouldn't think your prop issue is the problem.
Click to expand...

cant see them heating up that quick, mine certainly dont, i'd think thats a sensor / electrical fault.
you could also put your hand, carefully on the top of the engine to check.
 
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thanks dpb

by ir temp guage is that a heat gun reader excuse my blonde moment.

pulled the sea strainer out here was a bit of crud in there and also a small bit of the filter plastic is broken off. wondering if this would be sufficient to cause2017-07-10 09.37.26.jpg2017-07-10 09.37.26.jpg a blockage further along the system. no coolant in it either but there is a little in the bilge wondering if the cap released the pressure when it got hot
 
captaindan said:
thanks dpb

by ir temp guage is that a heat gun reader excuse my blonde moment.

pulled the sea strainer out here was a bit of crud in there and also a small bit of the filter plastic is broken off. wondering if this would be sufficient to causeView attachment 65097View attachment 65097 a blockage further along the system. no coolant in it either but there is a little in the bilge wondering if the cap released the pressure when it got hot
Click to expand...

Look pretty clean to me!
 
captaindan said:
thanks dpb

by ir temp guage is that a heat gun reader excuse my blonde moment.

pulled the sea strainer out here was a bit of crud in there and also a small bit of the filter plastic is broken off. wondering if this would be sufficient to causeView attachment 65097View attachment 65097 a blockage further along the system. no coolant in it either but there is a little in the bilge wondering if the cap released the pressure when it got hot
Click to expand...

This is the one I have:

http://www.maplin.co.uk/p/pocket-infrared-thermometer-n19fr
 
been some more developments took the top off and found that the belts have snapped checked the supercharger wheels and the external one is jammed stuck (seized) any recommendations or advice would be greatly apreciated

Kind
regards
Danny
 
The KAD42s have a quite complex belt arrangement, and there is an upgrade kit for them also as the original design is prone to issues. I would be tempted to get an engineer in who knows what he's looking at with these motors - the costs associated with cooking 2 KADs doesn't bear considering.

Volvopaul on this forum comes highly recommended.
 
We have just done a VP supercharger thread .
I advocated potential problems linked to constant running,relating to regular oil change ,or at least checking .
There,s an additional tip on belt dust and extending the longevity too
If its ceased ---begs the Q had it ever had the oil level checked or replaced ?

If you have not flooded /soaked you alternator
Burnt the tips of the turbo
Replaced a corroded elbow
Replaced a corroded riser
Replaced /refurbed a water pump seal

Then you have not YET had the full VP running costs experiance .
Then there's the leg (s) --- lets not go there !

New VP price for a supercharger €3000 + tax
Here

http://www.ybw.com/forums/showthrea...be-run-continuously-in-the-supercharger-range
 
captaindan said:
been some more developments took the top off and found that the belts have snapped checked the supercharger wheels and the external one is jammed stuck (seized) any recommendations or advice would be greatly apreciated

Kind
regards
Danny
Click to expand...

Oh Dear,

If it's the supercharger itself that has seized, then this could be quite expensive.
I think you will need professional help to sort this out.

Best Regards,
Dave.
 
to be fair it was the belts but my super charger had seized up on the sb engine. Belts seem to were a little quicker from the rust particles. i sanded the wheels down to make them smoother so am hoping this might remedy the belts premature life
 
If you don’t mind me asking was this problem on a boat you own now or a previous the only reason I ask is I’ve just bought a Martinique 38 as a project and the sb supercharger pulley was seized and your picture of the weed filter looked like a sunseeker thanks Adam.
 
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