The only significant difference that I can recall is the pistons which give a lower compression ratio to compensate for the boost pressure.

 

They didn't have VVT, so they were a little simpler.

 

The components that cause concern, mainly the tensioners, are the same. Do the engines have a susceptibility to breaking apart (not including the tensioners)?

 

No, but the 4.0, especially the SC version are subject to head gasket failure, especially if overheated. Replacement with the 4.2 mls gasket is the cure.

 

All great answers. Thank you. I had asked a lady who was selling a 2000(?) XKR if the CCTs had been changed, but she said her mechanic told her "it wasn't worth doing" because it was a "better engine". I thought the CCTs were the same. I'll pass on it.


Thanks again.