Tmd40A getting water in the oil?

[Danish CHB]

Hi guys
on one of my TMD40 A engines I’m getting water into the oils? Oilcooler is checked, pressure tested when dismantled…
the internal fw cooling system doesn’t seem to loose any water. After refilling with new oil and oilfilter, I tried starting the engine, and running it at 1600 rpm for 15 minutes..
after 15 minutes the oil level has increased with approx. 10mm on the oilstick and oil is now completely white…

is there a way that seawater can enter the engine?? It can’t be through the oilcooler, because the oil pressure on medium warm egine at 1600 rpm was 4,6 bar pressure, and seawater pressure is less than 1 bar…. I’m close to giving up!! It would be nice with some one who had exsperienced the same problem….now I have tried a lot, and until now it costed five complete oil changes and five new luboil filteres…..and a lot of work…

 

[BruceK]

If you are absolutely certain it is sea water and not coolant it has to be the oil cooler. You could always confirm this by bypassing the oil cooler temporarily and repeating the above experiment. There after it must be coolant.

Edit: it's worth noting that the entire engine will not be at 4.6 bar. I'd expect the return to sump to be far lower in pressure and indeed the oil cooler pressure relief valves in the 41 series and up open at 2.5kpa or 0.025 bar and I suspect yours would be the same or near enough.

 

[Danish CHB]

I have an extra oil cooler with housing and had both coolers cleaned and pressure tested at 4 bar pressure, while heating up the housing to approx.60-70 degr.celcius…but no leak at all….
In my opinion there is no other ways for SW to get into the oil system???

 

[Leighb]

Could it be that there is a leak from the sea water pump? I can’t quite remember if there is a possible leakage route there if a seal should fail.

 

[BruceK]

I have an extra oil cooler with housing and had both coolers cleaned and pressure tested at 4 bar pressure, while heating up the housing to approx.60-70 degr.celcius…but no leak at all….
In my opinion there is no other ways for SW to get into the oil system???

Then it must be coolant.

 

[gery w]

Is it a stendrive boat?

 

[volvopaul]

Could it be that there is a leak from the sea water pump? I can’t quite remember if there is a possible leakage route there if a seal should fail.

No pump is designed not to allow salt water past bearing there is an open gap to allow leakage

 

[volvopaul]

Hi guys
on one of my TMD40 A engines I’m getting water into the oils? Oilcooler is checked, pressure tested when dismantled…
the internal fw cooling system doesn’t seem to loose any water. After refilling with new oil and oilfilter, I tried starting the engine, and running it at 1600 rpm for 15 minutes..
after 15 minutes the oil level has increased with approx. 10mm on the oilstick and oil is now completely white…

is there a way that seawater can enter the engine?? It can’t be through the oilcooler, because the oil pressure on medium warm egine at 1600 rpm was 4,6 bar pressure, and seawater pressure is less than 1 bar…. I’m close to giving up!! It would be nice with some one who had exsperienced the same problem….now I have tried a lot, and until now it costed five complete oil changes and five new luboil filteres…..and a lot of work…

Take an oil sample the results will tell you if it’s salt water or from the closed system.
Have you pressure tested the closed system?
My 99% hunch is liner seals .

 

[Leighb]

No pump is designed not to allow salt water past bearing there is an open gap to allow leakage

Thanks Paul, I was not sure.

 

[Danish CHB]

Problem solved…reson was the sw pump, jabsco type, that had a shaft seal pushed out, and 100% blocking the “leakage gap” and sw was able to pass along the shaft into the motor….but without any drops through the Leakage Gap…..

anyway …Thanks for all your effort in solving the problem….