Talk Morgan Forums Morgan Sports Cars Morgan Three Wheeler & Super 3 potential engine disaster, oil pressure loss

Is the oil tank pressurised, I haven't really noticed any pressure when removing the cap.

If it is not pressurised then surely a rubber seal is not required.

What you do get is pressure pulsing as there is a breather from the crankcase connected to it (as well as the breather that goes direct to the throttle body) which is nominally controlled by a reed valve. Add in the amount of oil mist that is present in the air gap in the tank when it is running or just shut off and you get plenty of oil leaking from the cap if the seal isn't up to scratch. Someone (GLLOQ?? I think) did machine up a proper O-ring sealed plug for the inside of the filler neck rather than the sheet rubber pressed against the top of the filler neck which isn't a good sealing surface.
Previous Post

Yes, a shame they do this and don't give us all the information on known issues, so we can make an informed choice on which upgrades are important to us. A good number of us are now out of warranty and I would rather replace a small component at my expense if it saved the engine, then have to replace a complete engine through ignorance. You would think they would do this to save their own warranty expense.

A seal not resistant to oil in an oil tank is more important than say the NVH mounting for a noisy bevel box.

A new owner to a Morgan on taking delivery at the dealer should have a card given to them for the Talk Morgan website. I would think in proportion to cars out there, there are not many owners who know about this wonderful Savior of the M3W!

maybe interesting to have a sticky thread in the forum with known mechanical issues and occurrences as well as solutions

Thanks for the tip

Will check my oil filler cap tonight like I am sure everyone else is doing

A common problem. I advise viton over nitrile. The nitrile cannot handle the oil and heat.

Loosing the rubber seal into the tank has happened to me twice now, luckily with no damage done, I spotted it both times before most of it had dropped in. The dealer then drained the system etc.
Ironically the earlier tank cap ( which I now have ) seems more robust in this respect - it has a large metal washer holding the rubber in place giving it a lot of support.

As a consequence I dont screw the cap down hard now , as this puts twisting force on the rubber washer aggravating the situation.

Unbelievable this is still happening.

Unbelievable yes but depressingly actually true. I cannot understand how Morgan can risk an engine for the price of a decent seal. Its bonkers and i can't print what i'd like to do with my dodgy seal, or rather where i'd like to stick it - i'll save that for my next trip to the factory. Shame on Malvern - its just good enough.

It needs a Monza Cap.....!!

I spotted mine before it disintegrated & went into the tank. I made a temporary gasket out of 2 layers of gasket paper.

Tim