Hi everyone can anyone help with my drive belt
on my s type 2003 the belt won't stay in it's grove on the crank shaft . All other 7 pulleys seem fine .
have fitted a new belt and tensioner the belt is fitted correctly but as soon as I run the engine it rides back off the crank pulley by at least half of the belt .
the engine runs ok but it's a pain to understand why
is it possible the crankshaft pulley as moved towards the front of the cat .
I have tried to tighten the bolt but the engine turns with the socket .
many thanks Alan .

 

It is indeed possible that your crankshaft pulley is at fault. It could have moved, cracked, lost a bit of its edge, etc. Have you closely inspected the entire area? Have you watched the new belt ride off the pulley while someone else starts the engine? If so, can you tell what is happening?

 

Alan, it would be great if you'd give us a little clue as to which engine you've got...

Irrespective of that, given the information you've presented, I suspect you have a delaminating harmonic balancer...or as you say, the crank pulley has moved - same thing.
If you have the 3.0L, could be in for a stand-down. Several years ago I had this problem on the 03, and some months prior, the crank-damper supplier to Jaguar, a Canadian company, had been driven out of business because Americans decided they'd like to see what it would be like if you had a president worse than "Jimmah" Carter...and gave him two terms, to boot!
Motorcarman found one down in Houston and had it shipped to his shop and installed it for me. It was potentially the last new one in the world, at that time! Maybe they've moved the tooling and restarted the line, since? Otherwise, you're looking at removal, send off for refurbishment, return shipping, then re-install -so you'll be hard-down for 1-2 weeks, minimum.

Upon close inspection, you'll find the crank pulley is two distinct metal surfaces, separated by a polymer material. You can put an index mark across both metal surfaces. If they separate after engine operation, this diagnosis is confirmed. However, since your belt won't stay on at this point, I'm not sure there will be enough force on the outer circumference to separate the marks. Perhaps a more intelligent gent, such as Motorcarman will weigh-in on the applicability of the marking-test if you can't load the pulley up anymore?

 

For the cost I would just replace it with a used one off EBay.
They rarely go bad and a used one is a good gamble.
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The easiest way to remove the front pulley is to cut an old serpentine belt to match the diameter of the pulley, then use a chain spanner around the outside of the pulley to hold it. You may need a long bar with the 24mm socket to get it loose. A puller is then required to remove the pulley assembly from the front of the crankshaft.

The engine must only be rotated in a clock direction when viewed from the front of the vehicle, or damage to the main and rod bearings may result.

 

I guess it's not failsafe, but most delaminating dampers start making a short, high-pitched "chirp" for about 2-3 minutes on cold-start for about 6 months before they become unserviceable. At least all three of mine (S-type, X300 and Excursion dsl) did.

 

many thanks to you I will check and let you know

 

thanks for the reply I will check and let you know

 

thanks I will check and let you know cheers