30 replies to this topic

[mpialan]

1997 Mini MPI. My Engine will not turn through a full 360 degrees,it will turn approximately 350 degrees one way and then approximately 350 degrees back the other way. What could be stopping it rotating the full 360 degrees. My initial thought was a dropped/stuck valve but after an albeit very quick inspection, the valves all appear to be good.

Does anyone have any ideas?

Just to add the engine was spinning freely until last week and no major work has been undertaken.

Edited by mpialan, 20 October 2024 - 01:02 PM.

[Steve220]

Is this with the plugs out?

[mpialan]

Yes, plugs are out.

[PoolGuy]

Just to add the engine was spinning freely until last week and no major work has been undertaken.

Any non major work?

[mpialan]

No major work done to engine. Engine was turning freely until last week. Then starter wouldn't turn turn it over. My initial thought was that it had seized, but that is not the case.

[Lplus]

Where in the cycle is it stopping?  TDC? halfway round?

[mpialan]

I'm not sure of exact position it is stopping at the moment and have given up for now.

I have loosened off the rockers and inspected the top of the valves, all are OK. I am erring towards a broken valve stem and the broken valve preventing one of the pistons reaching the top of its stroke.

[Lplus]

I'm not sure of exact position it is stopping at the moment and have given up for now.

I have loosened off the rockers and inspected the top of the valves, all are OK. I am erring towards a broken valve stem and the broken valve preventing one of the pistons reaching the top of its stroke.

If a valve stem had broken i would expect to see the top of that vavle sticking up higher than the rest.

[mpialan]

If it's not the valve, what else could it be? Something is definitely jamming rotation.

[Steve220]

You haven't replaced anything on the clutch housing / wok have you?

[nicklouse]

So what work HAS been done?

[mpialan]

No work whatsoever. Engine was rebuilt about eight years ago but has done very limited mileage since. It is not a daily driver and is never over revved or driven hard.

[stuart bowes]

Sounds like you'll have to take the head off and have a look

Or get a cheap borescope off amazon plug into your phone and go in through the sparkplug holes

Edited by stuart bowes, 21 October 2024 - 04:34 PM.

[floormanager]

Long engine mount bolt?

[Icey]

Long engine mount bolt?

Having seen this a few time I was going to say the same.