AD41P ev limiting

[oncewaswafu]

AD41P Rev limiting

Hi all. Had a problem occur twice now, as follows.
Transitting Pompey harbour at hull speed, temperature climbs to 80 degC which is its normal OT.
Then, a while later, Temp gauge flickered and dropped to zero. Then, trial and error showed the engine would not accelerate above 2000rpm.
On the first accasion the temp gauge came back to life, and normal engine response was available. Yesterday, not so.
Hull sparkling, props ditto, new fuel filters, oil and filter. New impeller. Plenty of water out of the drive. Coolant level good.
I'm thinking there must be an interlock between the temp and the governor, as in the Overtemp scenario.
Would anyone like to comment? Or at least inform me where the temp sensor/sender is?

Thanks in advance

 

[oncewaswafu]

Re: AD41P Rev limiting

Unusual - there's normally someone with an idea!

 

[[2068]]

Re: AD41P Rev limiting

Temp sender below.
But I have no clue as to why a low temp reading would correspond with a rev restriction - it's a mechanically governed diesel.
It could be you have two different problems here.
Check belts for tightness, earth and connections on alternator etc. as well.

 

[Montemar]

Re: AD41P Rev limiting

You say engine will not rev above 2000 rpm. Do you tell this audibly or by only what the rev counter is saying? If the latter then whatever causes the temp. gauge to misread may also be affecting the rev. counter.

 

[oncewaswafu]

Re: AD41P Rev limiting

Thanks.. Its both. The rev counter shows 2000, the boat wont accelerate etc. I'm safisfied it is rev limiting. I'm off to have a look as soon as it's on a maintenance rack, check all connections etc.

 

[oncewaswafu]

Re: AD41P Rev limiting

Many thanks. I had a vague idea about it limiting due to bad connections, but if it's purely mechanical then that's out of the window. Thanks for the photo of the sender. I'm going to tighten / change the fan belts and see if that makes any difference, but as it has never run hot I can't really make a connection. There is something dodgy, or why would the temp drop from normal to bouncing off the bottom stop. Buti if there is no connection to the limiter, why would that have an effect? Who knows! Anyway, thanks again