Hi little but infi for all u series 4 xj6 owners I recently bought my fifth xj6 for restoration after buying I knew weren't charging battery after three weeks and power drain tests galore no close fixing problem eventually figured was alternator but also had squeak from belts so one morning gone car battery light on realise drive belt has snapped and gone completely rang motor factors bought two new belts fitted them took me two days messing soon new belts on worst squeal g ever!!! Worse than before and still alternator not working after two days an very frustrated I realised the alternator wasn't high enough on bar and belt was too loose so I bought an 80p pack ten mm washers this morning took top bolt off alternator adjuster put two more washers on managed force alternator up and get belt back on now belt was tight great first belt now on fan belt tension was terrible not spring loaded it awful bracket type system anyway must had on an off car twenty times in end had put two layers electrical tape round back clip to hold still just get tensioner to stay on tight enough adjusted it so was tight enough just get belt back on and slid it on tadah now moment truth I started up my jag xj6 3.2 1995 and guess what alternator was now working perfect instead being on ten volts in red was back up 14.5 and guess what else the squeak was gone completely so my advice on these cars is if u got squeak or alternator not charging u can guarantee u need new belt and tension tightening this can be done on drive belt by removing bolt hold alternator to adjustment bracket removing top bolt that holds bracket in place adding couple cheap metal washer to make pressure tighter and revolting alternator an bracket back on slider so tonight after weeks trying find problems all problems with my jaguar are solved I'm a happy boy but my advice is if it's squealing get new belts and tighten tension a little thought this might help some people seems be common problem if any one wants advice just ask cheers

 

My belt for SC was squeaking too. I have exchaned idler pulley and drive belt tensioner and belt. But squeaking remained. So I take out pulleys and there is (for me) inexplicable fact (see pic, yellow arrow).
The belt wipes on the pulley body and causes squeaking. I don´t know where is error, but I used all things new, belt from Jag and other OEM. But result is the same. It seems, that the belt is long, but it is "C2C37055". Any idea ?

 

Hi that is different to mine what year model do I have mine was drive belt too slack on alternator had tighten up actual alternator screws and bolts with washers to get desired tension mine xj6 3.2 1995

 

 

On older cars if pulleys don't line up can cause squeaking get a ruler put from each pulley to next if looks straight its not that if at slight angle your pulleys need aligning or u can buy special belts look on utube for checking pulley alignment if its this I can advise u couple things try cheers hope u get it sorted
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Hi.
Pulleys are straight, problem is only in length of belt. I try another (1310 mm) lenght and maybe it help. Thanks.