Hello Forum, I have a 1984 Jaguar XJ6 that I need to replace the head gasket on. I am however unable to loosen the top chain tensioning mechanism (pictured) because I don't have the special tool. I tried my needlenose pliers but couldn't turn it. Was wondering if there is a go around for this? I live in the US and I can only purchase these from overseas and that will take a while. Also to be sure, we loosen the center nut first, than turn the tensioning gear clockwise to loosen and counter clockwise to tighten correct?

Also the intake is stuck on the head pretty good, I have bottle jacks I plan to use for the head removal but I need to remove the intake first to get them under the head. Is there a trick to getting the intake off without breaking anything? Should I hammer in a pry bar or screw driver at the end of it towads the front of the engine and pry it off, I am concerned that will damage the mating surface though!?

And last, does anyone know the size of socket needed for the crank bolt to turn the engine?



Thank you in advance,

 

https://mossmotors.com/jd-2b-timing-chain-adjuster-tool

https://mossmotors.com/c3993-cam-alignment-tool

1 5/16" 12 point short socket
Rgds
David

 

Hello!

For the tensioner, you are correct - loosen the center nut, then tighten and loosen on the tensioner are opposite what they usually are (so it's clockwise/right to loosen). That metal tab that is sticking out in the 11:00 position in your picture has to be pushed in order to turn it. The tool makes it simpler, and they are not too expensive, but I've heard other folks make do with pliers and some creative hand positioning. I believe you can get the tool in the USA on ebay, and from various suppliers with domestic warehouses like Moss Motors, Welshent, etc.

The crank bolt is 1 5/16". I recommend a custom tool like David showcases in this thread, although honestly jumping the starter to get close then using the tool just for small adjustments worked well for me: Newbie engine questions (SIII) - Jaguar Forums - Jaguar Enthusiasts Forum

You will also want a camshaft alignment tool to get the engine to TDC, and may also want to look into a tappet stakedown kit for the exhaust side, as well as plan to measure and replace tappet shims as needed while you have it apart (there are some threads and youtube videos that go into details on this).

Finally, there is a guy on youtube who has an in-depth video series on pulling the head, making all sorts of adjustments, and replacing it. The channel is "Living with a Classic" - here's a link to the first video in the series: He's working on a 1975, but it's a very similar setup. He has a bunch of videos on other stuff too (suspension, etc.) that seem to be really great quality, and have helped me on a number of occasions.

 

Thank you for the links David.

 

Thank you very much for this, I think I can get the tensioner with the pliers I just didn't push in the metal tab. I'll try and report later.

Any tips on how to get the intake off the cylinder head?

 

Check very carefully that you have removed every nut holding the intake manifold to the head. I have seen this problem a number of times. The manifold should release easily.
I recommend a tappet stake down kit on both the intake and exhaust as I have had two occasions of inlet guides coming loose.
A camshaft alignment tool is absolutely essential. Beg, borrow, buy or steal one!
When you do get the head off NEVER repeat NEVER put the head face down on a flat surface while the camshafts are in place, or you will bend valves which protrude past the head's surface.
Cheers