30 replies to this topic

[PoolGuy]

Why can’t people answer simple questions?

[floormanager]

 

Long engine mount bolt?

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

 

Don't ask me how I know

[Gaz66]

Surely the long engine mount bolt would catch way before a 350° turn as it would be hitting the diaphragm in several places on the way 😬

[mpialan]

Why would the long engine bolt suddenly cause a problem after years of running fine,how could it move?

[Stu1961]

You say the engine spun freely until last week, did the engine stop suddenly while running/underload or did you discover the problem whilst trying to start it. With the rocker cover off can you see the valves moving or with no1 cylinder at TDC on its compression stroke are both valves closed?  

[Cooperman]

First of all, establish where the jam occurs (TDC and with which pistons at TDC) or somewhere else.

Then push the clutch right down and try turning it. If it then turns, you know that the jam is in the transmission after the primary gear.

If it still jams you need to remove the head as a first task and thoroughly check valves, push rod and cam followers.

Then, if no success, remove the starter motor and check that out.

Should that not identify the problem, you'll need to remove the clutch cover and flywheel.

If that doesn't identify the issue, it's engine out and take it all to pieces.

[68+86auto]

Here's an option which you might think is crazy but I've seen it happen on other British cars. The inertia starter slowly pushes the ring gear off, usually in one spot. The starter can then jam up and the ring gear could hit something else.

 

Check that the ring gear is on correctly the whole way around.

[Shooter63]

Here's an option which you might think is crazy but I've seen it happen on other British cars. The inertia starter slowly pushes the ring gear off, usually in one spot. The starter can then jam up and the ring gear could hit something else.
 
Check that the ring gear is on correctly the whole way around.

A 97 car will be on a pre-engaged starter unless its had some drastic surgery.

Shooter

[Lplus]

First of all, establish where the jam occurs (TDC and with which pistons at TDC) or somewhere else.

Then push the clutch right down and try turning it. If it then turns, you know that the jam is in the transmission after the primary gear.

If it still jams you need to remove the head as a first task and thoroughly check valves, push rod and cam followers.

Then, if no success, remove the starter motor and check that out.

Should that not identify the problem, you'll need to remove the clutch cover and flywheel.

If that doesn't identify the issue, it's engine out and take it all to pieces.

Generally agreed though if the jam is not at tdc  then I'd start by removing the starter and crank sensor before taking the head off.

[68+86auto]

 

Here's an option which you might think is crazy but I've seen it happen on other British cars. The inertia starter slowly pushes the ring gear off, usually in one spot. The starter can then jam up and the ring gear could hit something else.
 
Check that the ring gear is on correctly the whole way around.

A 97 car will be on a pre-engaged starter unless its had some drastic surgery.

Shooter

 

 

For some reason I thought it was an older one we were talking about. Anyway, I'd still check that the ring gear is ok.

[Stu1961]

Have you managed to diagnose the issue?

[mpialan]

On Friday I put a boroscope down each cylinder in turn, there was clearly something in cylinder number four. Yesterday I removed the cylinder head to reveal what was once probably an M6 headless screw or stud. How it got there, I have no idea, if doing any work at the top of the engine with the air box removed, I always shove a rag in the throttle body.

I cannot believe how lucky I have been, no serious damage to the piston or to the cylinder bore. Today I will polish out what little damage there is to the piston ready for putting it back together next weekend.

Thanks for all the comments and possible solutions.

[nicklouse]

Should be no M6 anything near a Mini.

[mpialan]

It was a little difficult to get an accurate measurement to be honest.

[Shooter63]

Should be no M6 anything near a Mini.

Try MPI exhaust manifold heat shield bolts, and apparently late model bumpers are m6 and Im pretty sure I've come up against other metric threads as well.

Shooter