Thread: Noisy 3.5

Unusual though it may be, it can happen to any alloy block with shrunk in
liners that have no more positive means of lateral location in standard form, it
would have helped if Rover would have pressed or dropped the liners all the way
down to the bore shoulder at the bottom of the block, then decked off the liners
flush with the block deck, this would have removed any potential scope for
movement or slippage.

In fact they did what you say but as the block cooled the sleeves would rise off the step. But seeing that 3.5s have 2MM alloy extra around the sleeves the inaccuracy of the moulds did not matter so much.

The real problem is that if a crack does occur, the water is able to migrate up between the sleeve and block then into the combustion chamber,as the tin gaskets did not fully cover the join between the sleeve and block.

If they would have used flanged liners , the problem would be alleviated to some extent, although the water can stilll go into the sump.

It all starts with an overheat and crack in the block behind the liner which causes a loss of tension between the liner and block.
Regards Philip A