Volvo MD11c advice.

[Alfredmylne]

I’m looking for advice regarding removal of the inspection hatch (Volvo call them lids) on the crankcase of a Volvo MD 11c. I understand the oil circulation system works on a pressurised basis so don’t want to do anything stupid. I seem to remember from other posts it’s a real faff to restore whatever the system is if you remove the part that the dipstick sits in.
So, can I remove the hatch without any precautions (engine cold and not running obviously) and also is the oil level in the sump lower than the hatch aperture? If it’s lower that saves me the job of pumping out the sump oil before starting the job.

Should mention that I’m removing the hatch because it’s leaking oil through one of the retaining screw holes.

Thanks in advance for any help that can be offered.

 

[pvb]

The oil circulation doesn't work on a pressurised basis, it works unusually on a vacuum basis, which is why the dipstick is sealed and screws in. The oil level in the sump should be below the bottom of the inspection lid, so you can just remove the lid. New gaskets are available from VP dealers, although the lids are obsolete.

 

[VicS]

As PVB says the crankcase is not pressurised, it is infact vented via a hose on the " ventilation cowl" at the back of the engine to the rear "frying pan" air cleaner

The dipstick and coarse strainer are part of the oil pump suction therefore always inspect, and renew if necessary, the O ring on the dipstick when checking the oil level. Like wise the Oring or gasket on the coarse strainer when checking that ( I found fibre washers in a plumbers merchants that were the right size for that)

When changing the oil we removed the dipstick/ coarse filter assembly and extracted the oil from there with a hand pump ( But also drained the last bit via the drain plug oh the bottom stbd corner of the sump) and refilled /topped up via the same route.

IIRC there are two different designs of coarse strainer. Ours could be removed easily with a large-ish spanner on a square . The other type ( older ?) required a special key.

Never run the engine with the dipstick removed or the oil pump will not suck up oil.



Take care when removing the bolts that secure the crankcase side covers. My recollection is that there is not a lot of metal round one of them!

 

[Jcorstorphine]

I had the predecessor of your engine, namely an MD2B which I hated with every fibre of my body and soul. One of its many nasty tricks was for the oil pump not to prime even though the dipstick was leak tight, the problem being wear in the oil pump. Having carried out a partial rebuild, the engine almost seized when I started it up due to the oil pump not priming. To get over this concern on subsequent work or oil changes, I fitted an oil pressure gauge as previous owner had messed up the oil pressure switch.