Timing chain

[muzza49]

I've had the head off my S to finally fix a noisy #1 inlet valve issue.
Head now back on and I made real sure that when I removed the head, that the cam shafts were set up with the Jaguar cam tool.
I also ensured that the chain did not move on the sprockets by securing them with cable ties.
Used the cam tool again, to ensure that the cams were in the correct position, when the head went back on.
I now find that timing chain has a lot more "play" on the inlet side compared to the outlet side.
I've tried adjusting the tensioner (which I removed when I lifted the head) but no joy.
Any comments/assistance appreciated.

[cass3958]

My only advice is check and check again then before you start her up rotate the engine by hand to make sure there is no interference between the valves and the piston crowns. Do this for three or four revolutions of the engine then check the alignment of the cams again with the alignment tool.

When you had the head off did you replace the chain tensioners or are they the originals? I have heard that they can stick in the retracted position so the tension on the chain is not tight. With the head off it is always a wise idea to replace the tensioners especially if they are the original ones.

[muzza49]

Thanks cass3958, can always rely on you for prompt, reliable feedback - much appreciated.
No, unfortunately didn't even think of replacing the tensioners, but the motor has done less than 5k since rebuild, so as long as they were replaced then, they should be good to go. Mind you, they stuffed all the shims up, so can't guarantee that they were replaced !
Motor turns ok and the cams always align correctly according to the tool - maybe the chain has always been a bit sloppy !.

[cass3958]

When you are referring to the noisy inlet valve on #1 is that Jaguar #1 at the back of the engine or Haynes manual #1 which they claim is at the front. If it is the latter mighten the loose chain be the reason for your noise. A loose chain might be because it has stretched and the tensioners can no longer take up the slack. Time for a new chain?

When I rebuilt my engine I had all the valves shimmed but once the engine had run in they all became noisy and tappy. Had them shimmed again and was pleasantly surprised at how quiet the engine became. Only problem was I could now hear the exhaust blowing at the joints so they all had to be resealed.

[muzza49]

Yes, definitely Jaguar #1 (firewall end).
I'll just have to see how it goes and if not right - start again - argh !

[muzza49]

I have removed the breather and cam covers to view/adjust the chain.
Would you believe that both sides now have the same tension, no sloppy chain on the inlet side anymore !
I suspect that the comment re "sticking tensioners" may be the answer and these have loosened after running the engine.
The good book states that "there should be slight flexibility on both outer sides of the chain below the camshaft sprockets".
I assume that by pushing on the chain and getting some small movement, I should be ok.
Happy days....

[cass3958]

Good to hear. Always worrying when you think something is wrong and cant quite get it right. Worse when you know something is wrong and can't find the problem.