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

4.2 straight 6 engine stuck?

Thread Tools
 
Search this Thread
 
  #1  
Old 08-22-2020, 05:26 AM
brinny's Avatar
Veteran Member
Thread Starter
Join Date: Sep 2015
Location: Yorkshire U.K.
Posts: 1,296
Received 424 Likes on 251 Posts
Default 4.2 straight 6 engine stuck?

my barn find car that has been stood for the last 20 years has a stuck engine. I have pulled the starter motor out to make sure it wasn't that. For the last 4 weeks I have been feeding the bores with various penetrants. The first 3 cylinders from the front of the engine drain away, the last 3 dont. The engine feels solid when I try to turn via the crank. Is this how an engine with stuck rings behaves or could it be something else. 1976 4.2 automatic. Thanks in advance for any help
 
  #2  
Old 08-22-2020, 05:52 AM
Join Date: Feb 2010
Location: Adelaide Stralia
Posts: 27,703
Received 10,544 Likes on 6,964 Posts
Default

Thats how they will feel. The rings will basically be rust "welded" to the bore (dry liner in this engine), and nothing will move, period.

An engine rebuild shop would take the bottom off, and using a "Jackhammer" style tool, basically drive the piston and dry liner out through the top, sacrificing the piston and liner. New style "stepped" liners are recommended for this engine as they have been known to "nip up" and drag a liner downward.

NOT what anyone wants to hear, but thats the way it is.

I used one of those tools back in the late '60's, when as an apprentice, I had to dismantle a Stutz Straight 8 that was well and truly seized. Got it apart, made pistons, modified some other brand liner, and all sorted.

In this case, another engine would be more economical in MY opinion. Screws the matching numbers, but there are number and letter punches out there, so not all doom and gloom.
 
The following 2 users liked this post by Grant Francis:
Doug (08-22-2020), Greg in France (04-26-2022)
  #3  
Old 08-22-2020, 06:17 AM
brinny's Avatar
Veteran Member
Thread Starter
Join Date: Sep 2015
Location: Yorkshire U.K.
Posts: 1,296
Received 424 Likes on 251 Posts
Default

Cheers grant. Never had the pleasure of a seized engine before so wanted to make sure it wasn’t something daft I’d missed. You may be right about an engine swap. Can’t afford a rebuild looking at some of the prices. Then again may have a go at it myself.!
 
The following users liked this post:
Grant Francis (08-22-2020)
  #4  
Old 08-22-2020, 11:29 AM
JagCad's Avatar
Veteran Member
Join Date: Jul 2012
Location: Walnut Creek, California
Posts: 6,796
Received 2,399 Likes on 1,880 Posts
Default

Circa 1958,built a T Speedster from junk and cast off parts.
I a "rebuilt short block. well, it was the sof a firehad ithe open f

Key board issue??

Using a bloclk of wood and a sledge, i drove the pisotons out. As they were iron, they remained intact.

Good babbitt!!!! Honed the bores, did a valve job, fitted other pistons and new rigs. it ran great !!!

Carl
 
The following users liked this post:
Grant Francis (08-22-2020)
  #5  
Old 08-22-2020, 12:27 PM
anjum's Avatar
Senior Member
Join Date: Dec 2011
Location: London
Posts: 936
Received 192 Likes on 169 Posts
Default

If you've got nothing to lose then stick some citric acid solution down the bores for a couple of days and see if that does any good.
Next thing to try is phosphoric acid.
 
The following users liked this post:
Grant Francis (08-22-2020)
  #6  
Old 08-22-2020, 12:40 PM
LT1 jaguar's Avatar
Veteran Member
Join Date: Dec 2018
Location: Wasilla,Alaska
Posts: 1,591
Received 1,108 Likes on 612 Posts
Default

Ahhhhh.... babbitt, the good ole days.

Dave
 
  #7  
Old 08-22-2020, 12:55 PM
Doug's Avatar
Veteran Member
Join Date: Mar 2008
Location: Pacific Northwest USA
Posts: 24,894
Received 10,952 Likes on 7,196 Posts
Default

Originally Posted by Grant Francis

In this case, another engine would be more economical in MY opinion..
Not that your opinion needs back-up from me, but I agree

In my experience, if an engine is seized up then you can bet the cylinder walls, pistons, and rings will be shot. At the end of the day it always comes down to a full engine overhaul....so why even bother trying to un-seize unless a full overhaul was in the plan to begin with?

A good used motor is a great alternative in this case.

All "IMO"

Cheers
DD


 
The following 3 users liked this post by Doug:
Grant Francis (08-22-2020), Greg in France (04-26-2022), Jag7651 (08-22-2020)
  #8  
Old 08-22-2020, 08:37 PM
brinny's Avatar
Veteran Member
Thread Starter
Join Date: Sep 2015
Location: Yorkshire U.K.
Posts: 1,296
Received 424 Likes on 251 Posts
Default

Originally Posted by anjum
If you've got nothing to lose then stick some citric acid solution down the bores for a couple of days and see if that does any good.
Next thing to try is phosphoric acid.
Thanks. Still soaking it at the moment. Looking like an engine swap.
 
The following users liked this post:
Greg in France (04-26-2022)
  #9  
Old 08-23-2020, 05:08 AM
redtriangle's Avatar
Senior Member
Join Date: Jun 2014
Location: Australian Capital Territory
Posts: 354
Received 112 Likes on 80 Posts
Default

Had the same issue with my Series 1. Tried for weeks with all sorts of penetrating fluids. Would not budge.

Ended up buying another Series 2 for $500. Turned out to be a "blessing in disguise", lots of useful spares, interior, fuel tanks, front brakes (4 piston) etc. plus of course the engine. The previous owner paid $7000 for the car, bought it "sight unseen".

I thought at first it would be a shame to part-out the car, until I nearly fell through the trunk floor due to rust!

Plenty of Jag "stories of woe" out there it seems!
 

Last edited by redtriangle; 08-23-2020 at 05:11 AM.
The following users liked this post:
Greg in France (04-26-2022)
  #10  
Old 04-26-2022, 12:14 PM
JeffR1's Avatar
Veteran Member
Join Date: Aug 2013
Location: Lake Cowichan BC Canada
Posts: 1,709
Received 726 Likes on 520 Posts
Default

Oxendine has to take the head off, starting with the cam shaft covers.
He thinks he can fudge it along and get it running.

Isn't that true Oxendine ?

You know what has to be done, there's all sorts of help here when you need it.

 
  #11  
Old 04-26-2022, 04:32 PM
JagCad's Avatar
Veteran Member
Join Date: Jul 2012
Location: Walnut Creek, California
Posts: 6,796
Received 2,399 Likes on 1,880 Posts
Default

Circa 58, I built a T Ford speedster from discarded junk, I got a short block for free that had been rebuilt, so he said. but spent a few years in the bsrn yard Froznen stiff. My tools to remove the stuck pistons was a chunk of 2 x 4 and a sledge!!1 got them out, a bit worse for the wear. but, Yahoo, great babbitt in the rods and mains. it became the engine tht I installed and ran great..

Carl
 
The following users liked this post:
LT1 jaguar (04-26-2022)
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
jimbalayajag
XK / XKR ( X150 )
0
11-19-2015 09:55 PM
Jagrick
E type ( XK-E )
1
02-12-2015 04:12 PM
Mr. Mohr
General Tech Help
3
09-22-2013 06:45 PM
Untame
XJ6 & XJ12 Series I, II & III
3
06-26-2013 06:20 AM
dneu
XK8 / XKR ( X100 )
5
09-10-2010 07:27 AM

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


Quick Reply: 4.2 straight 6 engine stuck?



All times are GMT -5. The time now is 08:28 AM.