Engine temperature variations

[Renegade_Master]

The surveyor called me today whilst surveying the boat and made the observations that stb engine seems to run hotter i.e. 175F Port 150F

On my Perkins the stb runs slightly hotter and Whilst you may think its something to do with calorifier thingy on stb side, whilst this will cause the engien to heat up slower than tother, ultimately the thermostate should keep them level IMHO.
Does anyone have the same symtom i.e. differing temperatures between engines.
Eh KAMD43's 230hp

P.S. He was complaining that the wind was 30kts with horizontal rRain in Menorca and his short flight this morning from Mallorca had him fearing for his life poor chap.

www.suncoastmarine.co.uk

 

[ArthurWood]

Had similar prob on my Merc V-8s until I replaced impellers. Now OK.

 

[Renegade_Master]

Could be Arthur also on my Perkins the port side has had all the cooler tube stacks cleared whereas the stb side hasnt, lots more water comes from the port exhaust now

www.suncoastmarine.co.uk

 

[DepSol]

No my Port engine is exactly the same as my starboard one ;-)

Dom

2003 is going to be a good year for me

 

[byron]

<font color=blue>My Perkins on my old Ocean 37 always had a similar variation except when revving slowly.

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[jimg]

No, I have twin KAMD43p's and they run at the same temp

 

[Renegade_Master]

Thanks fellas so could be impellors as Arthur says or blocked tube stacks. Or ?

www.suncoastmarine.co.uk

 

[DavidJ]

I've got KAD 43's which I think are the same as yours but stern drives not shafts. My guages both read 90 degrees C steady
David

 

[Renegade_Master]

whats that in F about 188 isnt it David sounds hot

www.suncoastmarine.co.uk

 

[DavidJ]

You got me worried so I looked in the book. The thermostat starts to open at 81 degrees and is fully open at 94 degrees so I guess I'm OK. I'm in the Med which in the summer the water temp gets to about 24 so I would expect to be on the high side.
thanks for the alert though
David

 

[Guest]

Hi! I would go for the tube stacks every time. then switch over temperature senders from engine to engine ( to check their reliability) having already inspected the water intake strainers, sea cocks and impellors.
Rob

robinwdunham

 

[DavidJ]

Hang on
There is an assumption that it's running too hot. Assuming the spec for a KAD 43 is the same as a KADM 43 ie 81C opening to 94C fully open then your port engine is running to cold not the S'board too hot. ie faulty thermostate... stuck open....easy job!!
David

 

[jimg]

No! Most of the time (in the UK at least ) the engines run about 75 c or 175 F ( approx) at cruising speeds.With good water flow the temperature does not require the thermostat to open. I spent an age with some-one recently on their TAMD41's on this sort of problem, the alarm was going off when running on full power. The thermostats were just opening under full load and the problem in the end was a duff sender.

 

[msimms]

Don't understand, if the thermostat is not opening wouldn't there be zero water flow? Please explain.

 

[DavidJ]

The engine will have a design temperature efficiency which for the KAD 43 will be between 81C and 94C which is why they select a thermostat which opens at 81. If they wanted it to work at 76C they would select a thermostat which opened at 76C

 

[jimg]

As you say the thermostat starts to open at 81 deg C and is fully open at 90 deg C. The Volvo manual I have states that the temperature should be 75-90 deg C. The alarm should sound if you go any higher than this. In the UK they tend to run at the bottom of that range, in the Med they probably run higher; but I think 90 deg C is getting to the limit.

 

[tr7v8]

I think it's the progressive scaling of the heat exchangers & oil coolers, a strip and descale is what is required. If the impellores haven't been changed for a while then they are probably slightly worn as well, which will reduce the sea water flow rate. The thermostats will have become lazy as well, generally opening slightly later and not as far.

Jim
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[Col]

Stbd engine useually runs the power steering. Poss restricted flow through p/steering oil cooler. I've successfully used Mr Muscle drain and sink unblocker, to shift the crud. Then Viacal to get rid of scale. Saves a strip down, and amasing what it clears out.

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[kimhollamby]

There's no power steering on the F36; but starboard engine is plumbed to the calorifier. It also runs the busier of the two alternators (the port alternator is virtually on holiday, while the starboard does all domestic load inc engine fans and the extra battery for the bow thruster if fitted).

It always seems bizarre, but a calorifier, once up to temperature, usually serves to keep engine temp higher.

Also watch out for voltage drops causing instrument imbalances.

kim_hollamby@ipcmedia.com

 

[longjohnsilver]

Col what's viacal and where do you get it?