Morris Minor Owners Club

Dear Morriests
My rocker gear cover breather tube had (for a long time) a slight kink in it that I removed by shortening it.
After a long run (120 miles) just as I was getting home, I noticed smoke from the bonnet.
On examination, this was drops of oil coming out off the big old-fashioned air filter gauze, dripping on the rocker cover and oozing onto the manifold. Removing the breather tube I detected a little oils smoke.

Question 1 - Have I developed a big problem?
Question 2 - What purpose doe the oil pressure relief valve play on a Gold Seal 984 cc engine and does this need checking regularly?
REQUEST - Any suggestions please.


Into - I have recently changed the oil and oil filter

I think some oil being pulled through the ventilation system is normal. Some Minors (mostly late 1098s I think, but don't quote me on that) came with a crankcase vent through the timing chain cover, which had a cylindrical oil separator attached to it. Perhaps you could find an aftermarket equivalent that you could fit into the breather tube.

Also, many Minors (948 and 1098) had the vent tube attached to a port on the carburetor and not the air filter, which would be better because any oil would simply be burnt in the combustion chambers.

The oil pressure relief valve relieves overpressures when they appear (as its name implies). I'm not sure what the pressure rating is on it, but that's what it does. The valve is very simple and functions using a long spring that's compressed; the only thing that can go wrong in the system is, over time, the spring loses its springiness due to constant compression. After fifty years, it's probably good to change the spring. Other than that, no maintenance necessary.

The relief valve is to limit the pressure of the lubricating oil to ~ 60 psi - nothing to do with oil fumes/condensate dripping from the air filter. I suspect a good clean -out of the rocker cover is required - and keep the hoses kink free.

Many thanks - to one and all

I do get oil dripping from the gauze onto the rocker cover, just like you. Over-oiling of the gauze after cleaning no doubt adds to the mess.