KAD 42 'running hot'

[simon4500]

KAD 42 \'running hot\'

Can anyone identify this prob; Twin installation on a sunseeker. Suddenly one is running at 95C when should be 75/80. Have had thermostats replaced, oil is OK, impeller is OK, dashboard instruments are OK. Also when on tickover after use the engine remains at 90C, whilst the other comes straight back down to 35C ish. The hot engine has the calorifer on it, and have taken this into account when thinking about this prob. Any ideas ?

 

[clivew05]

Re: KAD 42 \'running hot\'

Sorry dont understand the selections? /forums/images/graemlins/confused.gif

 

[dynamic]

Re: KAD 42 \'running hot\'

have you checked the Stacks are not bloked in the oil coolers and intercoolers?

 

[Viscount]

Re: KAD 42 \'running hot\'

Could be the sensor or the guage - I suggest swapping one at a time with the other engine.

 

[Erre]

Re: KAD 42 \'running hot\'

Faulty dial! /forums/images/graemlins/laugh.gif

- sorry - 'couldn't resist. i haven't a clue really.

 

[Deleted User YDKXO]

Re: KAD 42 \'running hot\'

I would'nt bother with a poll for this kind of post. If you've checked all the obvious bits as it seems you have, I would start with the simple stuff like checking whether the temp guage is telling lies. Maybe replace the sensor and/or guage? Is the seawater inlet or strainer blocked?
Are these engines intercooled? Maybe the intercooler is blocked or the calorifier? Is there a thermostat or valve on the calorifier circuit which is malfunctioning?
I guess some experts will be along in a minute
My money is on the sensor

 

[volvopaul]

Re: KAD 42 \'running hot\'

Engine with calorifier always runs hotter after a run to operating temp.

Check you have the same degree C stats as before there are sometimes different climate stats as for med use they are sometimes lower degree rating so they open earlier or later if in colder climate area.

 

[spannerman]

Re: KAD 42 \'running hot\'

Have you checked the exhuast bend for rust/blockage? its OK having all the rest of the system functional, but if the water can't get out it will overheat.

 

[clivew05]

Re: KAD 42 \'running hot\'

I have KAD42's aas well and the temperature always runs hotter on the engine that is coping with the Power steeering and the calorifier - your temps sound about right to me ... if it alarms on High revs then you have something wrong - but if it doesnt and always stays about the same difference then it should be fine ....

 

[clivew05]

Re: KAD 42 \'running hot\'

I still dont understand the options given in the original poll though they seem to be the same answer ... or question .... /forums/images/graemlins/confused.gif

 

[Dave_Snelson]

Re: KAD 42 \'running hot\'

Following the obvious swapping gauges and sensors, you need to check the flow of water through the system. The cal may be blocked, or maybe the inlet strainer on the raw water side or the exhaust elbow on the raw water outlet. 95C - if accurate - is quite hot.

BTW - you set the poll wrong but no matter.

Welcome to the forum, hope you get sorted.

 

[powerskipper]

Re: KAD 42 \'running hot\'

have a look at the colour of the water it make be a brown colour , check it against the other one, if it is mucky it may need flushing though, older engines sometimes do need this. as the water is older and muckier it can run hot as it heats up the mucky bits which hold heat etc. mite be worth a try.

 

[DoubleVision]

Re: KAD 42 \'running hot\'

Hi Simon and welcome to the Forum. I have kad 42s in my Sunseeker and I think I may be able to help. I had one engine over heating and virtualy exhausted every fix for it. Eventually it was the earth to the guage. I have known this on other Sunseekers too so I would suggest running a wire from a known good earth point to the negative on the guage (black wire). When I did it the temp dropped 10 degrees inmmediately. As its a simple fix I hope this is your problem too.
Paul

 

[A_8]

Re: KAD 42 \'running hot\'

There are IR type temp measurement devices on the market, some quite cheap. I keep one in the boat at all times just to be able to quickly faultfind a heat problem.

Get one and point at different locations on each engine to compare...ie start at the same place (close to the thermostats)on each engineblock to confirm that one engine is actually hotter then the other. Then follow the flow from the impellor, heat ex, intercooler etc until you find where it differs the most. Should be a good indicator as to where u'r problem is.

If one engine goes down to 35 at tickover I would suspect that one of the two thermostats on each engine is not shutting the flow.

/Michael

 

[alt]

Re: KAD 42 \'running hot\'

Sorry to be hi-jacking a thread, but while we're on the topic....

I am having the same trouble with my KAD 32, in that when I open her up to full RPM (3800RPM) the temp keep's rising, even up as far as 200F, when I see the temp getting that far I have to slow down again. I can sustain about 3500RPM, anything over that will eventually set off the alarm.

I am going to try the earth on the back of the guage to see. I changed the impeller (Other one was perfect so I kept it, may use it another time). I also drained the coolant (hoping that it was the heat exchanger)

Has anyone got any other tips before I change the thermostat?

 

[jimmy_the_builder]

Re: KAD 42 \'running hot\'

Furred up heat exchanger?

Cheers
Jimmy

 

[alt]

Re: KAD 42 \'running hot\'

Would a simple 'flush' help this at all? I replaced the coolant, and while doing so ran the hose through it (with the 2 exchanger drain plugs open) for a few minutes, no junk came out.

I will consider removing the heat exchanger, I need to see if it will be possible (Space tight in the engine bay)

 

[jimmy_the_builder]

Re: KAD 42 \'running hot\'

I'd get a ir thermometer per michael_j's suggestion above and use it to find out if the heat exchangers are doing their job before trying anything else. Maplins do them - have a look here.

Cheers
Jimmy