XJ6 & XJ12 Series I, II & III 1968-1992

XJ6 series 1 4.2 rebuild

Old 07-27-2016, 12:13 AM
Junior Member
Thread Starter
Join Date: Jul 2016
Location: Bright
Posts: 2
Received 0 Likes on 0 Posts
Default XJ6 series 1 4.2 rebuild

I have a XJ6 Series 1 4.2 auto. Picked it up with the motor out of the car. Previous owner had a V8 in it. Fortunately he kept the Jag motor, which I intend to put back in. It was running when it was taken out 8 years ago. To what extent should I rebuild it. Is it advisable to strip it right down and replace all seals, gaskets etc or risk it & just get it running. Much easier to do while its out of the car. Any advice from people who have done something similar would be appreciated.
Old 07-27-2016, 01:08 AM
Join Date: Jan 2014
Location: Delaneys Creek, Australia
Posts: 23,881
Received 4,564 Likes on 3,472 Posts

Welcome to the forums Aaron, when you have a moment please post an into thread in the new member area for a warm welcome.


If it was me I would at least do all gaskets and hoses, but there is a reason the motor was replaced in the first place. I would assume it was due for a rebuild.

It is not a cheap exercise, I have just been down that road. Not much change out of $6000 once you rebuild the head and bottom end then add in all the gaskets,fluids etc.
Assuming you will need a carby rebuild and transmission work as well it will work out fairly expensive, you could search for rebuilt one first out of a wreck.

eg, here is one available local to me. You may find something in your area.

Jaguar Long Stud XK 4.2 Engine | Engine, Engine Parts & Transmission | Gumtree Australia Logan Area - Shailer Park | 1117408444


Last edited by o1xjr; 07-27-2016 at 01:27 AM.
The following users liked this post:
Aaron748 (07-27-2016)
Old 07-29-2016, 04:23 PM
Senior Member
Join Date: Apr 2013
Posts: 167
Received 34 Likes on 30 Posts

Id pull the engine down and see what you find[thats what i did anyway], reason for poor running was a bent valve but i replaced all bottom end bearings, timing chains seals and gaskets, good hone and rering although in all honesty the bearings and rings were all good, also remove welsh plugs and water blast all the crap out of the water jacket. Regarding the head you may find a good series3 head for the right price otherwise just see what you have got...these engines are cheap 2nd hand in my part of the world, i picked up a engine and box off gumtree for $250, the car had been raided for its suspension-hotrod project. But as Clark says your engine was removed for a reason...
Old 08-06-2016, 07:18 PM
Senior Member
Join Date: Dec 2011
Location: London
Posts: 871
Received 169 Likes on 154 Posts

It's worth stripping the head and sump off to examine the bores and crankshaft. This will give you an idea of whether it's worth reconditioning or going for a reconditioned or second hand block.
Related Topics
Thread Starter
Last Post
George Type-S
XJ XJ6 / XJR6 ( X300 )
07-28-2016 03:56 PM
S-Type / S type R Supercharged V8 ( X200 )
07-24-2016 02:53 PM
XJ XJ8 / XJR ( X308 )
07-23-2016 11:03 PM
XJS ( X27 )
07-23-2016 09:28 AM
XJ6 & XJ12 Series I, II & III
07-09-2016 09:24 AM

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

Thread Tools
Search this Thread
Quick Reply: XJ6 series 1 4.2 rebuild

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
  • Ask a Question
    Get answers from community experts
Question Title:
Your question will be posted in: