Another Overheating KAD32 - Suspected Faulty Sensor....

[bc22]

Hi All

I hope you are enjoying this bank holiday weekend.

I am having some recurring overheating issues with my Sealine S23 fitted with a KAD32 engine and I am starting to suspect that it could be a faulty sensor or alarm.

An overheat alarm goes off above 90degrees C, but the boat rarely gets any hotter than about 91/92 even at max chat.

I have done a full service on the boat including a flush of both the Seawater and Freshwater sides, new impeller and new belts. Flow through the cooling system seems ok and the Flush brought the overall temperature of the system down by a few degrees.

The boat behaves beautifully until trying to get her up on the plain.

A few questions if I may to help me with my further troubleshooting.......We all know how hard it is to come across what you need in both the Volvo and Sealine manuals!


1) Is there a separate system for both the dashboard temperature gauge and the warning alarm?
2) What temperature SHOULD the alarm go off at? I can't find in the manual, but have read elsewhere a number of 97degrees? If so, this would suggest the alarm is at fault as the gauge doesn't go above this.
3) I assume the temperature gauge is indicating Oil temperature? If so where is the sensor on the engine, as i can't find any reference to this in the manuals? Is this worth a change or a clean up?

Any suggestions would be more than helpful.

Thanks all

Ben

 

[Scubadoo]

The kad32 has two temp sensors on the engine one is the gauge and the other is an alarm. There is no oil temp gauge just oil pressure as a standard fit.

If you are getting 91/92c then you are I think close to the limit of what is acceptable, mine used to reach 90c at speed but after Rydlyme flush and a few other changes mine is now at around 80c. If you are getting a alarm at 90c then I think it could be a faulty sensor, I vaguely remember mine going off when a plastic blocked the intake and the temp was near 100c, anyhow someone with more knowledge can confirm the actual alarm setting.

 

[bc22]

Hi Scubadoo; thanks for the prompt reply.

Do you happen to know the location of the two sensors? If its not measuring Oil temperature, what is it actually measuring?

 

[jrudge]

Is the boat / prop fouled? Temps rise at high rpm on a fouled boat. If not then back to the heat exchanger

 

[Scubadoo]

I think both are on the starboard side of the engine, I don't have the manual to hand at the moment.

Both temp sensors measure water/coolant in two different locations.

 

[bc22]

Is the boat / prop fouled? Temps rise at high rpm on a fouled boat. If not then back to the heat exchanger

Boat has been out of the water relatively recently and is in good nick. New props fitted this year.......

I think both are on the starboard side of the engine, I don't have the manual to hand at the moment.

Both temp sensors measure water/coolant in two different locations.

Thanks, will have a look.....

 

[DrumBeat]

Both of my Kad 32 run at Around 90. One of them is slightly over, touches 93 (200f) the other is just under 90.
The alarm only sounds if it reaches 100.
I think anything above 90 is probably too hot but I’m not going to keep throwing money at it to get a few degrees down.
it’s a nightmare trying to find out the cause!

 

[jrudge]

The exchanger will be blocked. Acid clean it. Don’t run a boat too hot.

 

[Portofino]

Get yourself one of theses .https://www.ebay.com/itm/185328651135?hash=item2b2672cb7f:g:8iwAAOSw5hViJbYC
Covids over now , no need to go round pointing it at peeps for heads . .Nope .Instead dive in the ER mindful of spinning belts etc and point it at stuff , the cylinders, the heat exchangers , the thermostat house , the elbow , top of rocker box , water pump faces ..etc etc .
Find the sensors or coolers and check the real temps As said 90 is calling for a cooler clean job .

 

[volvopaul]

Alarm sounds at 96 degrees centigrade, so it’s cutting in before then .
My rule of thumb is anyt above 200 Fahrenheit the coolers need inspecting .
Sounds like you have a faulty sender , it’s front underside of exhaust manifold, follow the cable near thermostat housing , the easiest way to change it is to remove the super charger.

 

[QBhoy]

Hi. I’ve recently worked on a friend’s s25 with this engine. Was overheating. The alarm sounded in the 90’s. The engine should run in the mid 80’s or close at most, I found. He had a few other issues for sure. But can I ask if the raw water strainer lid is definitely secure and sealing ? That would cause issue like this. As could a few other things. Like the fresh water side not holding its pressure. By perhaps the header tank cap releasing pressure before it should. Or somewhere else in that system. The raw water side drawing air somewhere too.
Cylinder head issues could also be to blame. That’s what happened to this particular engine I was at.