Deutz / Vetus PT43 Issues

[SFHB]

Hi folk ...

Please bare with me as to the full description of this message. I've just had a call from a very good friend that "Left England" a number of month's ago to tour the french waterways but has been plagued with engine issues soon after arriving.

He/they own a 43ft steel dutch cruiser fitted with a Deutz PT43 /106HP engine that keeps building coolant pressure and will not dump the pressure. So day one of cruising the pressure slowly rises all day and dumps coolant into the header tank. Over night the pressure does not drop but remains the same (I thought it should drop as it cools) and so day two of cruising the coolant pressure continues to rise, again dumping water into the header tank.

Day three release all pressure before starting, top up the coolant and start the cycle again.

It's has a cylinder head gasket changed and radiator caps have been replaced.

Can anyone put their finger on this fault please or if you need more info I'll get it as right now being stuck in a French marina is not ideal.

Many thanks

John

 

[volvopaul]

Hi folk ...

Please bare with me as to the full description of this message. I've just had a call from a very good friend that "Left England" a number of month's ago to tour the french waterways but has been plagued with engine issues soon after arriving.

He/they own a 43ft steel dutch cruiser fitted with a Deutz PT43 /106HP engine that keeps building coolant pressure and will not dump the pressure. So day one of cruising the pressure slowly rises all day and dumps coolant into the header tank. Over night the pressure does not drop but remains the same (I thought it should drop as it cools) and so day two of cruising the coolant pressure continues to rise, again dumping water into the header tank.

Day three release all pressure before starting, top up the coolant and start the cycle again.

It's has a cylinder head gasket changed and radiator caps have been replaced.

Can anyone put their finger on this fault please or if you need more info I'll get it as right now being stuck in a French marina is not ideal.

Many thanks

John

Single engine ? Feeds a calorifer? Possible problem with it split internally crossing pressure into engine coolant circuit . As it’s clear water you cannot detect it .
close off supply from engine to heating coil and re check .
seen this very often , engineers jump to head gasket failure

 

[SFHB]

Hi Paul ... Sent this to france. If there are further questions I'll post them.

Thank you - stay safe

John

 

[SFHB]

Hi again Paul et ALL

Here's an expanded message from France: All comments greatfully received and appreciated:

QUOTE:

Yes, it is a single engine.



When we first had the problem, during a longer run than normal and at high revs, I thought it was the calorifier or the heat exchanger so checked and rebuilt the heat exchanger and have replaced the calorifier. Had a pressure test done on the coolant system, with engine cold, and it was holding pressure fine. With the rare and short usage of the boat I thought the problem had been solved but once we left for France and were running all day and at higher revs it became apparent that it hadn't.

The quantity of coolant is not actually increasing, if you put back into the engine what has been expelled to the expansion tank it just brings the level in the engine back to normal.

It wasn't bad when we first set off but it was getting worse every day, so, before replacing the head gasket, we bought a CO2 tester which replaces the expansion tank cap and shows whether CO2 is getting into the coolant and it confirmed that it was, meaning that either the head gasket had blown or there is a crack in the head or block. Hence the decision to change the head gasket. Also replaced the header tank cap and the thermostat, even though I think they were both working fine.

After replacing the gasket it was vastly better so I think I was on the right track and gas is not visibly bubbling up through the expansion tank like it was before.

Now, after setting the coolant level in the header tank on the engine and in the expansion tank to the correct levels, the level in the expansion tank will stay the same on Day 1 of running 5 or 6 hours but Day 2 it will increase maybe 500ml and the Day 3 a similar amount until it is overflowing. The coolant does not flow back into the engine when the engine cools down, as I thought it was supposed to, but if you let the pressure off the engine header tank and let the coolant flow back into the engine from the expansion tank, the levels all return to correct, so no loss or gain, and you start again at day 1.

The expansion tank cap appears to have a one-way valve in it and you have to undo it to let coolant flow back into the engine so will it ever let coolant flow back into the engine?

Before and after the head gasket replacement the engine has run at the correct temperature and only starts to run hotter when so much coolant has been expelled that there is not enough left to cool it properly.

END QUOTE

John



There was a small amount of corrosion on the head surface where I think the head gasket had blown but either side of that was good flat surfaces, so I hoped it was enough to seal properly but maybe it wasn't and I just improved the situation and didn't cure it completely.



Hope this makes sense?