Morris Minor Owners Club

Worked fine yesterday .. this morning .. turn the starter Apparently no compression on number 1,2,3 .. rocker cover comes off .. the inlet valve's are all open and stuck there ... WIERD ..

Head comes off on Tuesday anyone care to speculate ?

Sounds like no oil has been getting up to the rocker shaft - and the rockers or the valves have seized. Have you recently had the head off ? Was the rocker gear soaking in oil - or bone dry - when you lifted the rocker cover off ?

the inlet valve's are all open and stuck there ... WIERD ..

have the squirrels been keeping their nuts in your inlet manifold?
;-)

Hope it's something simple, but stuck valves is a bit odd!

That was mine :>)

bmcecosse wrote:Sounds like no oil has been getting up to the rocker shaft - and the rockers or the valves have seized. Have you recently had the head off ? Was the rocker gear soaking in oil - or bone dry - when you lifted the rocker cover off ?

Rockers all fine and rocking .. valves stuck down with a screw driver under them they will not come up.

Interesting, if the valves will not come UP will they actually go DOWN any
further? If they will then I would suspect that the seat inserts have dropped
out and wedged the valves open! If they will not go any further down then they would appear to have siezed up but the puzzle is that it appears that the
engine was working normally when you switched it off!

The inlets don't have inserts do they? I know unleaded exhaust seats are hardened inserts, but if it's the inlets that are sticking then I wouldn't think it's that.

Could it be a lubrication problem? I'm thinking something like a failure of the filter, causing particles to get between stem and guide.

Or maybe valve springs.

The odd thing is to have three go at the same time - Can't imagine seats springs or valves' guides all sufferign the same failure like that at once

Most peculiar - but is there plenty of oil all over the rocker gear - AND valve stems ?

No, the usual unleaded head would only have exhaust valve seat inserts but
anything could have happened to the one in question. I was thinking on the lines of a badly rebuilt unit which had inlet inserts too. Unlikely but this is a
pretty unlikely fault we are discussing. Could the inlet valve guides have
moved downwards until they are preventing the valves from closing? This is
getting ridiculous!!

Could there be an excessive build of carbon above the valve cones as this has occured in three of four cylinders? I have experienced this before but not with a Minor.
But mainly it's been down to lack of lubrication.

Aye - but all of a sudden on all the valves - highly unlikely! You must remove the head for inspection - and then before re-fitting - PROVE there is oil coming up the little oil-way to the head - and then again prove there is oil getting up to the rockers, through the drilled rocker pillar - along the shaft - and onto the rockers. The rocker shaft should be plugged at both ends - has one of the plugs come out ?

Justinminor....well? will the valves go further DOWN or are they solid?

Are you sure the valves are stuck down ? When you take the rocker cover off - there will always be 2 valves held open by the camshaft - is this what you are seeing - or are they really stuck down ??

Sorry I've been down in Brighton watching my sister getting married.

I haven't looked at it again yet (Head change in the morning) ..

What i suspect is that the valves were opened by the camshaft and they have stuck there.

I think I know why as well ..

I picked up a jerry can (of mine!) at the stables and was surprised to find it about 3/4 full of fuel. I have a HORROR of storeing petrol anywhere but in the fuel tanks fo vehicles and certainly not in barn full of Hay.

I sniffed it, it was petrol .. So I poured it into the petrol tank ...

Turns out that it wasn't petrol .. a friend had borrowed it to drain a petrol tank that had accidently had five litres of diesel put in it ..

So we reckon about four litres of diesel in a moggie tank ..

It means very little to me as I have a very nice head here that I was going to exchange for an unleaded one ..

I'll exchange the buggered one instead ..

So we reckon about four litres of diesel in a moggie tank ..

I still dont see how that would have caused your problems, keep us updated on what you find.

It would have been very very smokey running with some diesel in the tank - and it shouldn't have caused this problem !

So I took the head off .. One thing is that the bores are in perfect condition with no wear at all, Which makes me very happy.

The inlet manifold was covered in a black treacley deposit .. Sticky and horrible ..and this continued onto the valves and was obviously causeing the problem. Also this morning the valves had returned to their "Normal" position ....

One new replacement head later (started first time with a nice cloud of blue smoke from the oil in the bores) runs fine ...

I still don't know what caused it .. I put in contaminated fuel but there was no smoke (which I would have expected)

The tank of petrol before the contaminated one was the contents of Max's petrol tank (which was half full) with 1995 vintage 4Star (I assume) ... Could that have had anything to do with it ?

Still stumped ..

The inlet manifold was covered in a black treacley deposit .. Sticky and horrible ..and this continued onto the valves and was obviously causeing the problem. Also this morning the valves had returned to their "Normal" position ....

Yucky treacle stuff - you really don't want that in the inlets!
Well done for finding the problem, but as for the treacle from mixed fuels, that's a new one on me. (sugar in the petrol causes treacle but that would have wrecked the rings too....

I hope she runs well with the new head, but if it was me Id be crossing my fingers that the rings are not sticky as well

rayofleamington wrote:

The inlet manifold was covered in a black treacley deposit .. Sticky and horrible ..and this continued onto the valves and was obviously causeing the problem. Also this morning the valves had returned to their "Normal" position ....

Yucky treacle stuff - you really don't want that in the inlets!
Well done for finding the problem, but as for the treacle from mixed fuels, that's a new one on me. (sugar in the petrol causes treacle but that would have wrecked the rings too....

I hope she runs well with the new head, but if it was me Id be crossing my fingers that the rings are not sticky as well

I'll do a photo of the combustion chambers .. slight carbonisation but nothing scary ..

There is a garage locally that sells 4star (real not LRP) .. I'm going to use that for a few weeks and hope it gets whatever it is out of of it's system ..

As you say the petrol you found was in a barn maybe someone mistook her for a horse & fed her sugar....

Taxi!