Tons have been written about timing chain tensioners but somehow I cant seem to find an answer.

I am chaing my cam cover gaskets and am looking at my timing chains.
The car is a 2002 XJR with about 170K miles. I didnt have any issues with the engine at all.

Looking at the timing chains I notice following on the secondary chains & tensioners
LH: there is no play in the chain. The tensioner squeeks when pushed in.
RH: there is a couple of mm. play on the chain and I am not able to push the tensioner in or out.
Both look to have been worn down a couple of mm. They seem to have a dark red plastic upperside and a metal part below.

Is there something wrong on the RH side? Should I replace tensioners and/or chains?

For the main timing chains, I have no idea how to check the tension/tensioners.
Also my timing chain looks very different from what I find in any pictures (see picture below)
Anyone?

 

That is the 3rd gen tensioners and Morse chain. You should be good to go.

 

Thanks!
Still concerned about the RH secondary tensioner not pushing in (or out) and the chain that seems a bit loose.

 

Looks good from the pics, the red is the neoprene guide, the part that would break was the body (which used to be plastic), for which yours is metal and as Brandon said...that's 3rd gen...02's came with that.

But, as you describe...one squeaks and the other is stiff... how far can you push the squeaky one? They both should be stiff. You really shouldn't be able to push these down...its why when they come to you new, they have a retaining pin in them that aren't to be release until you've completed the installation and its the last thing you do is pull those pins before buttoning up the covers. This puts the tension load on the chain, gives you a quiet motor and prevents "chain slap" or a rowling noise and/or timing jump.

 

The LH squeeky one can pushed in 3 or 4 mm. Chain tension however seems good.
The RH is stiff, however the chain gives about 4 mm. I can put a screwdriver between tensioner and chain without force.

 

Oil pressure will bring them up.

 

The stiff side sounds like your chain may be worn (i.e. stretched) a bit or the tensioner collapsed or as RJ said, just starting the motor should bring them up? But are they spring loaded RJ?
For the Primary chains you can feel them out the same way. Check for looseness and play.
Guides would be another concern. They are on the primaries and can crack and splinter and cause issues, especially if the chain catches a piece and it gets under a gear and throws the chain or causes a timing issue. I would run a bore scope down in to look them at minimum since your there. If you don't have one, you can get one like this off Amazon or eBay...
Way cheaper than a standard scope and you can explode the view. Be sure you get one with a light on it.

Being she's 18 yrs old, you may want to consider just doing the secondaries if the primaries are ok.
This pdf is for an XK8, but its still the 4.0L... http://www.jagrepair.com/images/Auto...eplacement.pdf
You can get the lock down kit off eBay (I did) for $35-40 (US) shipped, I'd send you mine if the shipping wasn't so outrageous. Chains and tensioners on the other hand depend on how far you wind up taking this?

 

Just bought a bore scope with LED to inspect my bellhouse after my starter broke in pieces. Will have a look as suggested.
For the rest, at this point I will just close it up and pay extra attention for any suspicious sounds. Need the car running and parts will take another week to get here.
Thanks for the help and explanations!

 

Dumb question, but were you checking the correct actuating side on each tensioner? If I remember correctly the left side (as sitting in the car) pushes up, while the right side pushes down. The side of the chain that's under tension from engine rotation isn't actuated by the idler.

 

Not a dumb question. No I havent checked. I am not an expert on this at all.
So, one chain should be on tension, the other not?

 

These tensioners have one pad fixed to the tensioner body and the other is attached to the piston (spring loaded) so it can be pressed in. The "piston pad" of the LH tensioner is facing up and you can press it down. The "piston pad" of the RH tensioner faces down so you will have to push it up from below.

To check the tension of the secondary chains, you need to rotate the engine clockwise (looking from the front) a little bit with a spanner on the crank pulley. Then both secondary chains should have no slack on their top or bottom sides.