How much oil should i be losing

[nickfabbri]

I have a 1980 ish volvo md5 in my boat and it is losing oil. Not a great deal but over the weekend when we were motoring for about 10 hours all in all I lost about 100ml. I know that old diesels lose oil but is this a normal amount? The engine is serviced regularly and all the filters etc changed. Many thanks

 

[johnalison]

That's a litre in 100 hours which for many people is a year's use. The engineers here will tell you, but it sounds within reasonable limits to me. I believe a diesel should be using a certain amount in normal use.

 

[Phoenix of Hamble]

Thats not significantly different to my oil consumption on a Perkins Prima....

 

[billskip]

First "are you losing oil? or are you useing oil?

All engines "use oil" if they did'nt they would soon stop working.

So its the amount of usage that concerns you.

Well as said 1ltr in a 100hrs (or a year ) is not a lot.

But if you take the same 100 hrs at an average of say 1800revs in an average car (with engine same age and engine hours) say speed average 40mph that is 4000 miles per ltr.

The above is a suggestion as to how you can asess resonabe oil consumption with a comparison, and not in any way accurate but suggested as a guide only.

I will proberly get laugh at for the above but to me it is a resonable guide

/forums/images/graemlins/laugh.gif

 

[nickfabbri]

Sorry, to clarify things. I collect about 100ml of oil in the bilge underneath the engine with about 20 hours use. Is that normal?

 

[billskip]

you correctly stated in your post that you were "losing oil".

it is usual for engines to get oil leaks, but it is advisable to stop these leaks if possible.

There should be telltale signs of where the oil is leaking from..if not obvious, clean the engine and after cleaning and a few hours use you should get some idea where the leak is.

Please do not pump your builge out into the water .

good luck

 

[VicS]

[ QUOTE ]
I collect about 100ml of oil in the bilge underneath the engine with about 20 hours use.

[/ QUOTE ] That is not too good. ideally you should not have any oil leaking. As suggested clean every thing up and then investigate the source after a short run. A sheet of newspaper under the engine will soon indicate roughly were it is coming from.

It could be a crank shaft seal, a gasket somewhere. the drain plug, the oil filter.

I dont know about the MD5 but other VP MD engines have an aluminium washer old the drain plug that corrodes away. (A fibre washer seems to be a suitable replacement). If it turns out to be seal then one of the "high mileage oils" or an additive that softens old hardened seals may be an easy solution.

 

[nickfabbri]

Does anyone know the name of an additive or high mileage oil that I could use. Also the oil collect in a groove near the back of the engine. So i guess it could be the gearbox drain plug.

 

[Bilgediver]

I don t know how you say you used 100 ML as the oil level will vary for many reasons after running....like wife moved....different trim....and also oil takes a while to drain back down....


John

 

[Bilgediver]

That is 100 ML too much....where is it coming from....rocker cover gaskets.....crankshaft oil seals...Gearbox....is it black or clean.???


John

 

[robind]

Ring Morris oils at 00 44) 01743 232200 ask for Andrew brown for technical advice they are specialists in heavy use oils as used in old tractors and other industrial plant as well as complicated racing vehicle oils. They have been at it for 135 years its a number worth keeping
Let us know how you get on! I reckon you have an oill leak, I dont know the engine but many volvos have small pieces of pipework for oil that age and split usually around the side of the engine on bigger engines the cam shaft doors. Have a good look around with a mirror before you do anything. hope this helps
Rob

 

[nickfabbri]

The oil is black. I have very shallow bilges as the boat is a twin keeler. My engine mounts stop the oil moving either forward or back through the bilge .So i can guesstimate how much oil is collecting. I have checked the engine over and cannot see any obvious leaks on the top and sides of the engine case. I have very limited access to the rear and underneath of the engine so I have not checked there.

 

[VicS]

[ QUOTE ]
The oil is black ........ I have very limited access to the rear and underneath of the engine so I have not checked there

[/ QUOTE ] So it is engine oil! the only way you'll find where it si comming from is to clean it all up and check carefully. Mirrors on sticks, wads of tissue. Do check that drain plug though.

Motor spares shops sell the high mileage additive and Castrol do a high mileage version of at least GTX. That may or may not be suitable for your engine.

 

[Bilgediver]

Possibilities are the crankshaft seal at the front. The crankcase doors on right side. the rear crankshaft bearing which will leak out of area in front of gearbox. governor linkage door on back of engine,oil filter seal and rocker cover seals.

The rocker cover seal leaks can be almost invisible except where the oil collects on various ribs etc as gravity pulls it downwards .

 

[RobinA]

For comparison, I have a similar age MD7A (twin cylinder 13hp), which was using a slightly smaller amount (than yours) before rebuilding last winter. The rebuild was for completely different reasons - a broken rocker.
Prior to rebuild, I had the impression that it leaked from many mating surfaces and seals. These included sump gasket, timing cover interface, oil seal on end of camshaft, raw water pump seal etc etc.
Following rebuild, it is now completely leak free (so far, touch wood etc)
In my opinion however, it would have been totally impossible to prevent oil leaks without a major rebuild. On the up side, however, it probably doesn't matter too much as long as you keep it topped up, and try and stop any major leaks you can find - they're tough old engines.
One other consideration that is worth mentioning - if the crank case is pressurising (i.e. worn rings, blown head gasket etc) then it will force oil out of all sorts of places.

Robin

 

[VicS]

[ QUOTE ]
if the crank case is pressurising

[/ QUOTE ] It should not pressurise if the crankcase breather is not blocked unless the rings etc were very very bad. then it would probably be very difficult to start.

Anyway the breather is something else to look at!

 

[chrishelen]

just a note here that i only just found out after lots of worrying about worn rings etc,the volvo 2000series has a pressurised crankcase system so its worth checking on.

 

[nickfabbri]

Thanks everyone. I realise that at some point a 27 year old engine will need to be either rebuilt or replaced. However as our sailing becomes more adventurous and we travel further afield my worry is that the leak could lead to a catastrophic failure in a very short space of time. If you belive that this problem can be dealt with by topping up the oil regularly and keeping an eye on the oil levels then I will sleep better at night. As previously stated we had the engine surveyed six months ago before we bought the boat and it all came back ok

 

[Bilgediver]

Gearbox oil
;;;;;;;;;;;;;

Does your gearbox share engine oil...????? Dirty black on gearbox dip stick?????

I know some may but most gearboxes have their own oil which is usually clear amber!!!


John

 

[nickfabbri]

No the gearbox oil is clear and added via a different filler