XKR 4.2 or 4.0?
Discussion
Quick question. I'm looking to buy a lowish milage XKR around the 2003/4 vintage but is there much difference between the 4.2 and 4.0L? Obviously 200cc and about 30bhp, yes? Engine aside, what other differences were there? I seem to be under the impression that there was a lot of grief with the 4.0 and the Nickasil liners but not with the later cars. Is this true?
From what i have read the 4.2 had all the faults sorted. The water pump is the metal one as opposed to the plastic one on the 4.0, The tensioners are metal, the earlier ones were plastic and apparently prone to failing. And obviously the engine is steel lined. This is just what i have read in reviews etc. I'm sure some one will be able to give more info.
pete5570 said:
From what i have read the 4.2 had all the faults sorted. The water pump is the metal one as opposed to the plastic one on the 4.0, The tensioners are metal, the earlier ones were plastic and apparently prone to failing. And obviously the engine is steel lined. This is just what i have read in reviews etc. I'm sure some one will be able to give more info.
That is correct, there are too many improvements to the engine to list hereThe extra 30BHP came not from the 200CC but from speeding up the supercharger
In fact I have now put a 4.2Lt into my 1999 XKR
pete5570 said:
From what i have read the 4.2 had all the faults sorted. The water pump is the metal one as opposed to the plastic one on the 4.0, The tensioners are metal, the earlier ones were plastic and apparently prone to failing. And obviously the engine is steel lined. This is just what i have read in reviews etc. I'm sure some one will be able to give more info.
The 4.0 was revised somewhere in 2000 - every source of information gives a slightly different date or method of checking - some claim it was in the introduction of the 2000 model year in September 1999 others suggest you can trace which engine a particular car has fitted by the VIN number.The revisions include a change from plastic to metal impellor vanes on the water pump, a different throttle body and a switch to steel dry liners rather then a Nikasil plating directly on to the aluminium bores. There was also a Mk 2 design (still plastic 'tho) of secondary timing chain tensioner introduced and retro fitted to the earlier engines if customers complained about a rattle on start up - if it didn't fall to bits to bits and smash the pistons into the valves first.
Providing a 4.0 - even a early Nikasil plated one - has had the water pump and thermostat changed, a new throttle body and the third generation metal bodied secondary tensioners fitted and has a good or very good history of regular oil changes then an 4.0 car should not be dismissed completely.
Nikasil bore errosion and subsequent loss of compression was mainy due the use of high sulphur fuel combined with short trips which never allowed the engine to warm up. Allowable sulphur content in fuel was reduced from 150ppm to a much lower figure in Jan 2000 so any Nikasil engine built after that date - including mine - would never have been exposed to the cause of the bore errosion and there's a school of thought that a Nikasil coated engine (which of course I agree with
) is superior in terms of bore wear and frictional losses to a later steel liner one. 
Now due to work commitments I can't pick it up till near the end of the month. Myobb said:
Prior to picking up my XK8 from a service saw a XKR in the workshop. Apparently the water pump failed and the engine over heated. Result? A new engine required which Jaguar will supply for £5,300. There is a moral in this.
Ouch! Fortunately, I just bought mine from a Jaguar dealer and comes complete with a fresh service and a 1 year warranty. I should be ok for a year then (touches wood). Jaguar steve said:
pete5570 said:
Providing a 4.0 - even a early Nikasil plated one - has had the water pump and thermostat changed, a new throttle body and the third generation metal bodied secondary tensioners fitted and has a good or very good history of regular oil changes then an 4.0 car should not be dismissed completely.
I'm going to look at a 4.0 2000 XKR. Is there anyway of telling if the mods have been done and if not, are they expensive to do?2000 XKR, might be Nikasil but no issue as it cant have been damaged. Water pump and thermostat , cheap no worries. Tensioners MKII so spring loaded no warning of failure. Assume not changed unless paperwork to prove. Just had my MKIIs swapped for the latest MKIVs fitted in 04
Edited by P700DEE on Tuesday 20th April 09:55
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