one cylinder not working

Post by **pim123** » Sun Oct 15, 2006 2:00 pm

Number 3 cylinder stopped during driving, replaced points, cables, sparkplugs. Same problem. I think that if I've got a hole in the piston, the pressure would push out oil from every hole of the engine, this is not the case. Oil pressure about normal. What could be wrong ?

Post by **bmcecosse** » Mon Oct 16, 2006 7:15 am

Burned out valve is most likely - but could also be problem in the dizzy cap. Get the starting handle out - ignition OFF - turn the engine over by hand - do you feel 4 even compressions - or 3 good ones + one easy one ? If it was piston or ring problem - there would be clouds of smoke and as you say oil and fume coming out.

Post by **simmitc** » Mon Oct 16, 2006 11:32 am

Also, are you sure that it's only one cyclinder that's out? I've seen quite a few where the head gasket goes between 3&4. Doesn't affect oil or water as those channels are still sealed; but does reduce power on both cylinders. Usually a loud popping noise too. Valce more likely though. Check compression, then "off with the head".

Post by **pim123** » Mon Oct 16, 2006 3:59 pm

Simmitc, you are so very right !
We just measured the compression of the cylinders...nr 1: 10 Bar, nr 2: 10 Bar, nr 3: 2.5 Bar, nr 4: 2.5 Bar. Cylinders 3 and 4 are working but not normal. No water in the oil. My colleague anex meganic also came to the conclusion that is has to be the head gasket between 3 and 4. So as you say: Off with the head ! (tomorow evening, any tips ?)

Post by **simmitc** » Mon Oct 16, 2006 5:01 pm

Make sure engine is cool and drain radiator before you start !! Then it is essnetial to follow the torque sequence in the manual for the nuts on both the head studs and the rocker gear; both releasing & tightening. Release in reverse order to tighten. With rocker gear off, shake push rods before removing in order to ensure that tappets stay in their right place - otherwise the oil can cause them to stick to the rods and that just gets messy. Just follow the manual and all will be fine. Good luck.

Post by **pim123** » Mon Oct 16, 2006 5:02 pm

tnx !

Post by **Onne** » Mon Oct 16, 2006 6:00 pm

It is not very hard to do. Just make sure both surfaces are flat and clean

Post by **bmcecosse** » Mon Oct 16, 2006 7:12 pm

You said one cylinder not working - not two!! With the gasket blown between cylinders the car is almost impossible to drive. But that is indeed your problem - the thing is to determine WHY this has happened. Has the head been disturbed recently ?

Post by **pim123** » Mon Oct 16, 2006 7:32 pm

bmcecosse, I thought it was nr. 3 that wasn't working at all. But after compression measurement and visualy chekking with a 'see-through' sparkplug thingy it appeared to be nr 3 and 4 working with less power. The car is still drivable, although I haven't done that for no more then the minimum needed. The head has not been altered with. Only thing that happened is a new timing chain and gears.

Post by **Onne** » Mon Oct 16, 2006 7:36 pm

Roy probably forgot that you are in Holland. Even with one cylinder you'd still move, since there are no hills!

Post by **pim123** » Mon Oct 16, 2006 7:37 pm

Post by **bmcecosse** » Mon Oct 16, 2006 8:01 pm

Ah so! I had this once - tried to get the car home - had to stop after a mile, it was obviously going to do some serious damage. Walked a mile to buy a gasket (and a mile back) - then changed the thing at the side of the road using basic hand tools in the kit ie no sockets!! It lasted 6 years - and was perfect when I took it off to fit the 940 head in Spring of this year.

Post by **pim123** » Mon Oct 16, 2006 9:07 pm

I'm getting more hopefull now that after changing the gasket it wil be a happy Minor again and a happy owner !

Post by **nebogipfel** » Mon Oct 16, 2006 10:01 pm

bmcecosse wrote:Ah so! I had this once - tried to get the car home - had to stop after a mile, it was obviously going to do some serious damage. Walked a mile to buy a gasket (and a mile back) - then changed the thing at the side of the road using basic hand tools in the kit ie no sockets!! It lasted 6 years - and was perfect when I took it off to fit the 940 head in Spring of this year.

They make 'em tough in Scotland

Did you torque the head by waiting for the click in your elbow joint?

It's always worked for me

Post by **bmcecosse** » Wed Oct 18, 2006 10:12 am

I pulled it down as hard as I could using an 8" ring spanner - it lasted for 6 years and even then was still fine.

Post by **pim123** » Thu Oct 19, 2006 7:25 pm

New gasket...Car is running smoothly again! Thanks for your advice all !

Post by **bmcecosse** » Thu Oct 19, 2006 7:42 pm

Well done. Don't forget to torque it down after a few miles running - and reset the valve clearances.

Post by **pim123** » Thu Oct 19, 2006 8:34 pm

Ok, will do ! tnx
Learned a lot of watching my colleague doing the work and explaining everything he was doing. Until now I had only some experience with 2-stroke motorcycle engines when I was young. Looks like I have as much fun with my morris fixing it when it is broke then driving it...