XKR engine problems

[hog68]

Hi

I have a 1999 XKR convertible with ( i believe) the original Nikasil engine. Mileage appears to be a genuine 76,000. Due to poor running and misfiring at 75,000 i had the supercharger hoses and gaskets replaced at a total cost of £350. All ran fine for 1000 miles ( 3 months) and then the same happened again last week only this time the car stopped altogether. I am advised that oil is carrying over into the supercharger probably from wear in the Nikasil bores/ broken rings and then contaminating/ breaking down the supercharger seals.
I have seen the evidence of this on the old seals. The oil level had dropped slightly on the dip stick and i had driven the car fairly hard on short journeys.Another repair of £350 and all is running ok, although there is a slight petrol smell. Is engine replacement the only answer, or if warmed up correctly and driven more lightly could all be ok ?

Any advice greatfully received.

Hog 68

[mike020150]

With the loss of high sulphur petrol (many years ago) the nikasil problems have largely gone away because nikasil in the absence of h s petrol is a good thing. Unless the engine has been overheated, the problem is unlikely to be current damage to the nikasil treated bores. However, if you have signs of oil usage, it could be due to bore damage or valve stem wear. A Jaguar specialist should be able to complete a quick blowby test to confirm or eliminate nikasil issues. It shouldn't be expensive and would give you an indication whether the problem could be dealt with relatively cheaply (a head issue) or not (bore damage). An early indication of nikasil issues is poor cold starting. Mike.

[hog68]

Many thanks Mike. The garage is sure that the problems with the supercharger hoses failing are caused by oil contamination, and that in turn is a result of oil loss via the bores/ rings.
However the car does start/ run fine, and did in the cold weather. I have been quoted a re-con engine complete with steel-lined bores supplied and fitted for 3.5K.
I think the car may have over heated at some point before i purchased it as there is a receipt for head gaskets and a header bottle being fitted in the history file. I agree that a blow-by test to confirm would be worth the relatively small expense. Two other 'independent' specialists have both said that they would be able to tell with-out doing this though! Is there any evidence of anyone else having had the same senario of misfire/ breakdown due to the supercharger hoses/ gaskets failing due to oil contamination? Hog 68 ( Andy)