volvo penta md5b oil leak

[mrmaynarduk]

Hello all! new to the forum! although not new to boating..

I purchased my second yacht around 2months ago which was fitted with a volvo penta md5b diesel engine.. its been running great for the 2months ive now owned the boat.. i tidyed up the engine and bay with some fresh paint yesterday.. no know issues or leaks but today when i was running it up to go out i had a quick look in the engine bay to find oil leaking from underneath the engine some where?! gutted!! anyways its rather hard to even get my head in there to see where its actually leaking from so i have taken a picon my fone to find what looks to me like the casing gasket is where its leaking from? i will try to add a picture if i can.. does anyone know what the leak could be from? and does anyone know if i will need to take the engine out to replace the gasket if that is the culprit? just i didont want to take it out if i could help it.. anyone with any help/info on these engines would be much appreciated!

Many thanks all!

 

[Akestor]

Hello i have an md2b which is different, but now watching the md5b here
https://www.marinepartseurope.com/en/volvo-penta-explodedview-7742220-21-14989.aspx

I would start from locating the leak ( is it from the sump connection to the upper parts?) then check if the bolts keeping the sump in place are tightened as they should ) I checked the md5a manual (cant find an md5b) but doesn't give tightening torques for these bolts so you have to do it it by feel.
If the leak continue then why not make a new gasket? I guess the sump cannot get out without taking the engine out. But see if there is even some small room bellow the sump, you could unscrew, let the sump rest at the bilge, install the new gasket and put it at its place again. Hope it can be as easy as it sounds!

 

[VicS]

Welcome to the forums

I am afraid it is not easy to identify the location of the leak from the "picon my fone" or from your description of "the casting gasket"

Perhaps you could give a more precise description by referring to the parts diagrams http://www.marinepartseurope.com/en/volvo-penta-cat-7742220.aspx

I think you will have to locate the source by cleaning the area thoroughly and then running the engine while watching closely

You may be able to reduce the leak by very carefully and evenly tightening the bolts in the area but don't over do it or you might make it worse.

 

[mrmaynarduk]

Many thanks for your replys ok i shall check all bolta ect and go from there.. i have cleaned the area best i can and ran it up but now it wont leak.. atleast not that i can see the leak.. think i may have to take it for a run and get it under load and see if it leaks further.. im hoping its something simple as ive just spoken to the prvious owner and he said the entire engine was rebuilt less than 30 hours ago so hopfully something has come loose.. he did mention that he had a suspecion that the oil lift pump to crank case gasket maybe the culprit as thats the only gasket that hadent been replaced.. these engines are pretty new to me though hence the need for some advice.. im pretty good with mechanics most the time so il get the tools out and see what i can do/find.. im just not sure what im looking at at the mo

 

[mrmaynarduk]

bit of an update.. seems to me the oil is actually comeing from around the cylinder head on the sides where the head gasket sits and was driping down hence why it was on the underside of the engine.. so i took off the rocker cover and retightend the head bolts.. im hoping it now stops as i did manage to tighten the head bolts up a little more.. time will tel.. i had an interesting chat with the previous owner who informed me he had carried out the following work just before he sold it to me.. which was new piston and rings.. honed the cylinder.. had head skimmed..new gaskets ectect so im thinking/hoping it was just due a retighten of the bolts after the rebuild.

 

[VicS]

bit of an update.. seems to me the oil is actually comeing from around the cylinder head on the sides where the head gasket sits and was driping down hence why it was on the underside of the engine.. so i took off the rocker cover and retightend the head bolts.. im hoping it now stops as i did manage to tighten the head bolts up a little more.. time will tel.. i had an interesting chat with the previous owner who informed me he had carried out the following work just before he sold it to me.. which was new piston and rings.. honed the cylinder.. had head skimmed..new gaskets ectect so im thinking/hoping it was just due a retighten of the bolts after the rebuild.

Tightened them in the correct sequence to 70Nm ?

 

[mrmaynarduk]

Yes Vic i done them in the correct order all to 70nm :encouragement:

 

[Akestor]

Good you have new gaskets/pistons and bored cylinders. But if the leak is from the head gasket that means that oil is passing up from the rings and in the combustion chamber which is not good for a "new engine". But if this was the case i assume the engine would be smoking a lot of burned oil from the exhaust. Is there a tube on the rocker arm mechanism coming from the crankshaft? If there is, it is the lubricating tube and this might be the point of leak (if it is loose). So with head being in an angle the oil drips at the side.

 

[RichardS]

Good you have new gaskets/pistons and bored cylinders. But if the leak is from the head gasket that means that oil is passing up from the rings and in the combustion chamber which is not good for a "new engine". But if this was the case i assume the engine would be smoking a lot of burned oil from the exhaust. Is there a tube on the rocker arm mechanism coming from the crankshaft? If there is, it is the lubricating tube and this might be the point of leak (if it is loose). So with head being in an angle the oil drips at the side.

There will be several oilways passing through openings in the head gasket and these will be on the outside of the gasket so a "loose" head could result in oil finding its way out to the block without the combustion chamber being compromised, although that could well be an accompanying problem.

Richard

 

[SAMYL]

More than likely the leakage is from the rocker cover gasket.

Wipe the engine almost dry with tissues then sprinkle/blow talcum powder onto it to make it turn white.

Run the engine and you will easily see from where the oil is coming.

 

[mrmaynarduk]

Thanks for all your replys! Akestor no there is no smoke coming from exhaust. she runs great with no know issues as of yet hence why i want to get on top of this oil leak. be a great shame to kill the engine when its just had alot of work done to it. akestor could you possibly show me that tube you mean on a diagram picture? as im not sure which tube you are relating to? Samyl.. funny you should say that as when i had the rocker cover off yesterday i relised there is no rocker cover gasket fitted atall.. which is probly adding to the oil seapage down the side of the head.. il be ordering one of these soon although i may just go for the complete head gasket kit which includes the rocker gasket.. as my thinking is maybe the preious owner fitted a cheap head gasket hence the leakage.. but who knows!

 

[Akestor]

There will be several oilways passing through openings in the head gasket and these will be on the outside of the gasket so a "loose" head could result in oil finding its way out to the block without the combustion chamber being compromised, although that could well be an accompanying problem.

Richard

Thats relieving to hear! (combastion chamber not compromised)

 

[Akestor]

Thanks for all your replys! Akestor no there is no smoke coming from exhaust. she runs great with no know issues as of yet hence why i want to get on top of this oil leak. be a great shame to kill the engine when its just had alot of work done to it. akestor could you possibly show me that tube you mean on a diagram picture? as im not sure which tube you are relating to? Samyl.. funny you should say that as when i had the rocker cover off yesterday i relised there is no rocker cover gasket fitted atall.. which is probly adding to the oil seapage down the side of the head.. il be ordering one of these soon although i may just go for the complete head gasket kit which includes the rocker gasket.. as my thinking is maybe the preious owner fitted a cheap head gasket hence the leakage.. but who knows!

This are the tubes i am talking about but its on the md2b (with banjo fittings). I am not sure its the same on the md5. I guess there should be a tube somewhere for the rocker arm lubrication though.

I bought a new head sets for very good price online here https://poseidonmarine.eu/index.php. Also good prices in thermostats and lift pumps.

 

[VicS]

This are the tubes i am talking about but its on the md2b (with banjo fittings). I am not sure its the same on the md5. I guess there should be a tube somewhere for the rocker arm lubrication though. View attachment 71408

I bought a new head sets for very good price online here https://poseidonmarine.eu/index.php. Also good prices in thermostats and lift pumps.

No it does not appear to be the same

I have been looking at the on line workshop manual and the official parts list but I cannot work out how oil reaches the rocker shaft . If there is no gasket on the cover then that is almost certainly going to leak.

The oil feed to the rockers my be via a passage through the block and the head. If so then there is a pressurised pathway which also may leak if the head is not torqued down correctly or if the head gasket is dodgy ........ is it anew one wonders or did the PO reuse the old gasket?

 

[mrmaynarduk]

I was told by the previous ownr it was a new head gasket. could a cheap head gasket cause a simular issue? its 100% seaping out around the head gasket.. just got back in from a 2hour run and its deffo leaking from around the gasket! im debating weather to change the head gasket at this stage as i realy dont see what else could be the issue? like i said i have retightened the head bolts but its still leaking could i cause much damage if i continue to run it like this? obviously im keeping an eye on the oil which is still just under full. its not a major leak but it annoys me its there and it shouldnt be there lol Akestor no there is no oil pipe running from the head to the crank.. i think its probly like Vic said.. it must pass the oil up through the head/cylinder passesges ect

 

[RichardS]

Provided that there is not oil spraying out all over the place, then it is very unlikely to do any harm is you keep an eye on the oil level and whether there is any water in the oil.

However, I would check/replace the head gasket at the end of the season and would not start a transatlantic until it's sorted.

You might well find that the engine has overheated at some point which is why the previous owner had the work done. He should have had the head checked and skimmed at the same time as it is probably distorted. If he didn't he has been badly advised.

Richard

 

[VicS]

I was told by the previous ownr it was a new head gasket. could a cheap head gasket cause a simular issue? its 100% seaping out around the head gasket.. just got back in from a 2hour run and its deffo leaking from around the gasket! im debating weather to change the head gasket at this stage as i realy dont see what else could be the issue? like i said i have retightened the head bolts but its still leaking could i cause much damage if i continue to run it like this? obviously im keeping an eye on the oil which is still just under full. its not a major leak but it annoys me its there and it shouldnt be there lol Akestor no there is no oil pipe running from the head to the crank.. i think its probly like Vic said.. it must pass the oil up through the head/cylinder passesges ect

Its a nuisance but as Richard says keep an eye on the oil level and check the oil condition to be sure no water is getting into it.

Its not a big job to take the head off though with view to replacing the gasket provided the head is not warped.

 

[Akestor]

The oil feed to the rockers my be via a passage through the block and the head. If so then there is a pressurised pathway which also may leak if the head is not torqued down correctly or if the head gasket is dodgy ........ is it anew one wonders or did the PO reuse the old gasket?[/QUOTE]

MD5A's manual confirms the internal oil path


If the gasket is new then maybe a check for head distortion as Richard suggests? Skimming is an inexpensive job ( at least here).

 

[scottie]

For what it’s worth I recollect that the MD5 was marked made in Norway and is inclined giving a very low profile I think that several bits like valves cam followers etc came straight from the Volvo parts bin but the block head and crankshaft are unique

 

[mrmaynarduk]

yes i have kept an eye on the oil level which is firmly staying around the max mark.. no signs of water in oil as mentioned.. oil is black with no milky crap in there. i messaged the previous owner again to confirm what he had previously told me and yes the head was skimmed when the rest of the work was carried out and also he used a new head gasket.. could a pattern head gasket realy go bad that quickly? engine has just under 30hours on it since the rebuild.. think i may have to just order the complete head gasket kit and just replace it just so i know its done. guess this is the trouble with trusting other peoples workmanship.. i will post back with any updates as soon as ive done something about it lol