Oil & water leak...

wazza

wazza

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It is said that oil & water don't mix, well they do unfortunately in my bilge (sort of)...

I believe our water leak (only a trickle when only when the engine is running) comes from the impeller housing which should be easy enough to fix..
BUT it's the oil leak which worries me... no idea. Now my main concern is, is it doing any damage to the engine? It's not a tremendous amount and the oil is black not a a gray watery worrying colour.
So what do you all think, am I being an idiot for thinking its ok and fill up with oil every few times I go out??
Btw... it's a Volvo MD17C if that helps... and thanks in advance for any tips:)
 
wazza said:
It is said that oil & water don't mix, well they do unfortunately in my bilge (sort of)...

I believe our water leak (only a trickle when only when the engine is running) comes from the impeller housing which should be easy enough to fix..
BUT it's the oil leak which worries me... no idea. Now my main concern is, is it doing any damage to the engine? It's not a tremendous amount and the oil is black not a a gray watery worrying colour.
So what do you all think, am I being an idiot for thinking its ok and fill up with oil every few times I go out??
Btw... it's a Volvo MD17C if that helps... and thanks in advance for any tips:)
Click to expand...

Needs action fairly quickly if sump oil goes grey, as water will get inside the engine and corrosion will start soon enough. Also oil/water emulsion lubricates far less well so causing wear and possible damage to loaded moving parts like big ends.

The leak needs to be dealt with before it does more harm: it is the seal behind the water pump, where the pump drive shaft comes through from the engine. A common fault, that needs prompt attention, but fortunately is both cheap and easy to rectify and not expensive. There is a small drain hole which drains water off before it gets in to the sump. When (not if) this blocks and it will, your engine oil will go gray and you will have to flush the engine through as well - messy and time consuming! Catch it now. The oil leak is likely to be the same problem - the water pump oil seal, but not necessarily. The only way to find oil leaks anywhere else is to clean everything off thoroughly, run the engine up until it is hot, then do a bit of detective work! Only life threatening to the engine if you have an emergency and have to run it hard for a long time, or the leak gets worse without you noticing between top-ups.
 
How much oil?

I don't know this particular engine, but typical areas to look at are rocker cover gasket and head gasket (both near top of engine). Clean it up as previous poster says. Worth checking that dipstick seats properly. Hope you don't have a hole in your sump as I did once...

If you can keep your bilge water-free and dry, then lay some oil absorbent mat in it and then you should be able to work backwards from the drips.
 
oldharry said:
Needs action fairly quickly if sump oil goes grey, as water will get inside the engine and corrosion will start soon enough. Also oil/water emulsion lubricates far less well so causing wear and possible damage to loaded moving parts like big ends.

The leak needs to be dealt with before it does more harm: it is the seal behind the water pump, where the pump drive shaft comes through from the engine. A common fault, that needs prompt attention, but fortunately is both cheap and easy to rectify and not expensive. There is a small drain hole which drains water off before it gets in to the sump. When (not if) this blocks and it will, your engine oil will go gray and you will have to flush the engine through as well - messy and time consuming! Catch it now. The oil leak is likely to be the same problem - the water pump oil seal, but not necessarily. The only way to find oil leaks anywhere else is to clean everything off thoroughly, run the engine up until it is hot, then do a bit of detective work! Only life threatening to the engine if you have an emergency and have to run it hard for a long time, or the leak gets worse without you noticing between top-ups.
Click to expand...

When you say "The leak needs to be dealt with before it does more harm" are you now talking about the water leak? As silly as I feel to ask this question, but I must, as I am not mechanical minded, but want to try:) I changed the impeller pump housing cover last season and I believe that is where the water is coming from..
As to the oil leak, sorry to sound extremely stupid but where abouts is the the water pump oil seal??? I be a little confused, aye.... ;)
 
Behind the impeller housing is the drive for the pump which connects internally to the engine. The shaft that drives the impeller has two seals on it, one to keep the water away from the engine and the other to keep the oil from getting near the water. In between the two seals there is normally a hole in the casting which drips water (or oil) if either of these seals fails. If not fixed water and oil can mix.

If the water is just coming from the front cover, replace the gasket. As already advised for the oil leak you need to clean the engine completely and see where the oil is coming from. There are many places where it can leak out if a seal or gasket has failed.
 
I would agree with the previous post's in as much it will be the WATER PUMP.

The pump should be removed after closing the sea cock and draining out the water.

There is a shaft this also must be checked to ensure it is clean and smooth.

Change the water seal and the oil seal.= job done

Highly unlikely to be the impellar cover. It also is unlikely that you will have to do any flushing!!

Fair winds

Peter
 
Thank you for your help & input, I'll attempt a strip down and hopefully Robert will be my Dad's brother..
 
Two other possible sources of oil leak to the above - If you recently serviced the engine and fitted a new oil filter. Often one forgets to remove the older rubber sealing ring and screws the new one on top of the old, buried in the seal groove. If you haven't fitted a new one this may or may not be a source.
As the MD17 is getting on a bit you could have an oil leak from the front bearing, or sometimes resulting from a slack crankcase fastening.
The first checks are those mentioned by others previously, then a closer look.

ianat182
 
Bugger.... Firstly thank you all for your help and advice.

Changed the water pump seals and it doesn't seem to have worked. Possibly, a little hard to be 100% and I will continue to investigate the problem. BUT good practise for me to change things in/on the motor:)
 
Funny, or maybe not so funny you should say that but yes it was..
But having said that, after re-installing the pump house and running the engine hand under the housing, no water and definately no oil.
 
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