Faulty Bukh Temperature Sender?

[Little Dorrit]

When these go rogue do they tend to ground at a lower temperature than normal? I have an alarm when the engine warms up. There appears to be a 'normal' water discharge and although I haven't checked the water temperature the engine head is not excessively warm when the alarm goes off. I was wondering if anybody has any insights into telltale signs if the sender is faulty as opposed to a more serious problem? I have recently changed the exhaust elbow and replaced the impellor.

 

[RichardS]

The senders are not usually expensive so you could just replace it, or buy a cheap temperature reader (£5 max) or IR temp gun (£20 max) and see what you're actually dealing with.

Richard

 

[Little Dorrit]

The senders are not usually expensive so you could just replace it, or buy a cheap temperature reader (£5 max) or IR temp gun (£20 max) and see what you're actually dealing with.

Richard

Thanks, I'll go for a replace first and see what happens.

 

[Rhylsailer99]

Is it the 2 prong one or the original bukh sender . You could place it in a pan of water and check the temp as it heats up then make sure youbget a closed circuit at around 70deg I think it goes off.

 

[Rhylsailer99]

Also check the thermostat is not stuck and clean out the therostat housing cap and block .if you need a replacement I know the one to buy as I replaced mine a month or so ago.

 

[Little Dorrit]

Also check the thermostat is not stuck and clean out the therostat housing cap and block .if you need a replacement I know the one to buy as I replaced mine a month or so ago.

What one did you buy?

 

[Little Dorrit]

Is it the 2 prong one or the original bukh sender . You could place it in a pan of water and check the temp as it heats up then make sure youbget a closed circuit at around 70deg I think it goes off.

There are two prongs, one for a temp gauge and one acting as a ground when the engine overheats.

 

[Little Dorrit]

I'm not sure how these work I am hoping when they fail they ground at lower temperatures?

 

[Rhylsailer99]

 

[Rhylsailer99]

Furneaux and ridall i also bought the vdo and fitted thats as well so I can see the temp.

 

[RivalRedwing]

When these go rogue do they tend to ground at a lower temperature than normal? I have an alarm when the engine warms up. There appears to be a 'normal' water discharge and although I haven't checked the water temperature the engine head is not excessively warm when the alarm goes off. I was wondering if anybody has any insights into telltale signs if the sender is faulty as opposed to a more serious problem? I have recently changed the exhaust elbow and replaced the impellor.

check the pipe feeding water into the block - it can become blocked. Water flow is not diminshed, it just all goes around the bypass. The blockge can be subtle and out of sight around the u bend. A piece of monel wire can be effective in clearing it.

Thread on its removal here: Raw cooled Bukh DV24 salt crystals on engine block

 

[Rhylsailer99]

I ran barnacle buster for 8 hours through the block and the water flow improved 10x at the end of the flush. I removed the thermostat and pinched the bypass pipe and used a bilge pump to push the fluid through the block.

 

[Rhylsailer99]

And don't take the flywheel off just buy a mini socket set and you can just about get the Allen bolts out .

 

[Mort]

Not sure which Bukh you have, but if its not the sender and temp appears ok, , check on this forum about faulty temp alarm and the fix for it, common issue, especially with DV20's

 

[Poignard]

And don't take the flywheel off just buy a mini socket set and you can just about get the Allen bolts out .

Another way is to shorten the short leg of a hex-key.

 

[Rhylsailer99]

View attachment 106318

These senders fail. Reluctant to buy a third I decided to put the original bukh sender in my thermostat housing. Whilst removing the sender it crumbled, and now half is stuck inside the block. I think they're made from brass and maybe not suitable for a raw water cooled engine.