Running Temperature for a Perkins 3HD46

[gilly1964]

Hi all. Looking for some advise, could any one tell me the correct temperature my Perkins 3HD46 should be running at please regrades Paul    

[Tony Brooks]

Direct raw water cooled, or tank/keel cooler/heat exchanger. Typical values across all engines, direct raw water 60 to 70C, the other 80C+. In all cases, depending upon the thermostat setting. Not sure how this helps, so why are you concerned.

[magnetman]

If it is much over 80'C it is probably overheating.

I wonder if this might be an overcooling subject. 

 

 

Plus of course remote temperature gauges may not always be entirely accurate. 

[Tony Brooks]

1 minute ago, magnetman said:

If it is much over 80'C it is probably overheating.

I wonder if this might be an overcooling subject. 

 

 

Plus of course remote temperature gauges may not always be entirely accurate. 

 

That is why I asked what prompted the question. It could be an apparent overheat, underheat, or, as you say, a faulty gauge. It would help to know exactly what type of cooling system it has, and if it does seem to be a fault, a bit of history leading up to it.

[gilly1964]

22 minutes ago, Tony Brooks said:

Direct raw water cooled, or tank/keel cooler/heat exchanger. Typical values across all engines, direct raw water 60 to 70C, the other 80C+. In all cases, depending upon the thermostat setting. Not sure how this helps, so why are you concerned.

Keel cooled/heat exchanger just thought she was running hot, temp reading 115 C if gauge is reading correct ?  

Purchased boat 4 years ago been out of water till 2 months ago , she runs ok oil, fuel filters all changed but she has blown off  Bowman 3419NP Keel Cooled Manifold Blank End Cap when gauge reading got 135C, she cruised 10 days earlier with no issues when gauge read 75C for a 40min cruise       

[Tony Brooks]

Properly installed keel cooler systems do not use a heat exchanger for coolant cooling, but may use an oil cooler for a hydraulic gearbox. The exhaust manifold (the Bowman) looks exactly like the same item with a heat exchanger core in it, except the keel cooler one has just two, usually large diameter, hose connections, while the heat exchanger manifold has four hose connections, two large and two small, plus the raw water pump.

 

I am certain 115C is definitely incorrect, but as the engine was not spewing steam, my money is on a faulty gauge reading in the first instance. I would be looking to change the temperature sender BUT note that the gauge and sender has to be matched, there are two standards US and European. if you mix them the gauge will either read about half or twice what it should be.

 

Make sure the alternator/water pump drive belt is properly tensioned and make sure the cooling system has not run out of antifreeze mixture. If you actually mean skin that cooled, make sure you bleed the tank and top up the system if required. It could be air/gas in the skin tank. Check these things before buying a new sender, or use an infrared thermometer to measure the actual temperature of the engine.

[gilly1964]

Cheers  will do , thanks for your help will get back to you as soon as i have checked over all items you have kindly mentioned in you last message    

[StephenA]

39 minutes ago, gilly1964 said:

Keel cooled/heat exchanger just thought she was running hot, temp reading 115 C if gauge is reading correct ?  

Purchased boat 4 years ago been out of water till 2 months ago , she runs ok oil, fuel filters all changed but she has blown off  Bowman 3419NP Keel Cooled Manifold Blank End Cap when gauge reading got 135C, she cruised 10 days earlier with no issues when gauge read 75C for a 40min cruise       

 

Blowing off the end cap doesn't sound good.

[Bee]

The temp gauge on Bee started reading hot a while ago, turned out to be some awful DIY connections at the back of the gauge. Note to self - do it properly next time.

[BoatinglifeupNorth]

What is the canal running Temperature of a keel cooled engine  60-70 degree ish?  On normal speed 2-4mph?

[StephenA]

9 minutes ago, BoatinglifeupNorth said:

What is the canal running Temperature of a keel cooled engine  60-70 degree ish?  On normal speed 2-4mph?

 

Depends on the engine and the thermostat that's in place. Our BMC 1.5 sits at about 80 once it has warmed up.

[BoatinglifeupNorth]

Yes I should of made it 80*

[Ex Brummie]

I had to chNGE THE SENSOR ON MY 4108M and as the thread was smaller was provided with a bush. this I installed, and then bled the sensor. This meant I had the sensor in 'dead' water and it overread as the bush took it out of the flow except for the bottom.  when I installed it without bleeding, it read correctly.

 

Sorry for the capitals, didn't notice til I'd posted

[Tracy D'arth]

Your boat has been out of the water and the overheat started when it went back in?

Was it blacked whilst out?  Have they put too much blacking on where the skin tank is?

[Tony Brooks]

11 hours ago, StephenA said:

 

Blowing off the end cap doesn't sound good.

 

I did not understand that bit of the post, and that definitely sounds like boiling, but the OP did not mention steam. If the end cap or hose blows off a pressurised system, then the over 100C coolant would likely flash off into huge amounts of steam. Odd, it was not mentioned.

 

Good shout @Tracy D'arth , hopefully the OP will confirm if it has been blacked.

 

It is also worth mentioning that if a bad overheat occurs, many thermostats will vent their wax, so they then open at a higher temperature than they should.

 

 

 

 

Edited November 21, 2023 by Tony Brooks