The End?

[T5SOR]

I have a metallic banging noise from under the cam cover area around 1750 rpm only and there is no sign of it below or above this rev range. Thinking it could be the big end, crank wobble issue or cams?

Might be the end for my 1989 1.6

[Gilhooligan]

Probably just the tappets. Make sure the oil is topped up or change it. I find that when mines does it, driving the car hard and using the full rev range stops it.

[T5SOR]

Having driven MK1 MX5s for 8 years I would be very surprised if it was only the tappets.

It has done well to get to 100K with a very wobbly crank!

[Gilhooligan]

Is it a short nose crank?

[T5SOR]

It has an 8 slot pulley, but the car is a 1989 model, so I am pretty sure it is a short nose crank engine with a long nose pulley.

[MonkeyDust]

Second-hand engines are cheap. If the body is in reasonable condition there is no reason scrap it.

[ronime]

T5SOR said:

It has an 8 slot pulley, but the car is a 1989 model, so I am pretty sure it is a short nose crank engine with a long nose pulley.

The pulleys cannot be swapped between the two types of crankshaft nose.

[MX-5 Lazza]

ronime said:

T5SOR said:

It has an 8 slot pulley, but the car is a 1989 model, so I am pretty sure it is a short nose crank engine with a long nose pulley.

The pulleys cannot be swapped between the two types of crankshaft nose.

So I guess it's had an engine swap in the past. Does the engine number match up?

[Digby]

If not an engine swap, it could be a short nose block with a big nose crank.

(Long nose pulley is still 4 slots btw as it's just a service part)

[T5SOR]

Sorry for the delay, been busy with house moving and a pregnant Mrs.

The car has low compression on cylinder 4. That and the crank wobble has made the car unrepairable. Looking at 1K to get back up together.




Mike

[T5SOR]

Digby said:

If not an engine swap, it could be a short nose block with a big nose crank.

(Long nose pulley is still 4 slots btw as it's just a service part)

I thought all SNCs were 4 slots and all LNCs were 8 slots? Has been on every MX5 I have owned.