Jaguar Forum banner
1 - 20 of 20 Posts

·
Administrator
Joined
·
10,053 Posts
Check the belt for cracking or splits. Once a belt starts to squeak though, it’s usually terminal and requires replacement.

Easily check if it’s the belt, just put a bit of wd40 on it and the noise will go, still there it’s the tensioner.
 

·
Registered
Joined
·
4,343 Posts
Mine does this when the weather is cold and the car has sat for a few days, or if the air is especially humid. I had my belts changed under warranty just after I bought the car (4 years ago) as it was doing it on every cold start but as it's only doing it under fairly specific conditions I'm putting it down to those conditions.

Of course, now I've said that...
 

·
Super Moderator
Joined
·
6,468 Posts
The squeal on start up is usually the belt slipping on a pulley wheel - I know, obvious :)

It happens as the belt loses tension and typically is heard only for a few seconds. This could be because the adjustment has slipped, the belt stretched over time or the belt worn so far that it is no longer grippy enough, or a combination of any of these. If the belt has gone hard, overly smooth, etc., it may take longer to stop slipping, probably as it gets hotter and softer from friction.

You can get a sticky belt spray to deal with the very slight cases. If the squeal goes using the spray, it is a sign that whatever is the cause is, it is not far gone. If the belt looks fine, just re-tension it (may be easier said than done depending on access). Adding a lubricant like WD40 helps the belt to slip quietly so in the long run will wear the belt faster and may cover up a worsening situation.

If the squeal is not coming from the belts but a pulley or tensioner wheel bearing, then one should investigate a bit more closely.
 

·
Premium Member
Joined
·
23,737 Posts
“Beltslip” is the stuff to use to get rid of the squeak but in all honesty, best to change it.:mrgreen:
 

·
Registered
Joined
·
4,343 Posts
I find it hard to believe that the belts could need changed as few as 2 years later (first time it happened after changing mine) on a car that does maybe 3k miles per year though. In my case, as far as I know both belts and all tensioners were changed. I don't have the service schedule to hand but I'm sure the interval for auxiliary and S/C belts was 10 years or 100k miles on the 4.2s at least. Especially cold or humid weather could leave condensation on the belts and/or tensioners too so that would cause a brief squeaking on cold start too and surely that's no cause to change belts and tensioners?
 

·
Super Moderator
Joined
·
6,468 Posts
Modern belts are very durable. The auxilliary belt on my S-Type is original and looks like new. I expect I "should" change it but ...

Rubber timing belts are more critical so we typically change them before anything goes wrong. You could try tensioning the belt again if it appears loose.

However, another fault could be a sticking driven component like a water pump or an a/c compressor. Extra resistance would cause the belt to slip. The squeal is just the symptom. Always worth checking for the cause. I'm not sure about the condensation theory only because this is one of the the warmest parts of the car and condensation will not be really expected. Probably just that the belt has stretched a little and the mechanic did not tension it quite right.
 

·
Registered
Joined
·
4,343 Posts
You're absolutely right with the other possibilities but the main reason I suspected condensation was that the first time it happened it was an especially humid day - to give context, I started the car, drove out of the garage and within seconds there was condensation on the outside of the windows and body panels. I guess very cold weather could cause the metal pulleys to contract a little too, until they've warmed up a touch. It's only ever done this very occasionally and only on especially humid or cold days, certainly since changing the belts originally.

I'll monitor this and look into it further if it persists.
 

·
Registered
Joined
·
330 Posts
Discussion Starter · #15 ·
Okay I've had a look at the belt (couldn't get the plastic belt cover off due to the fiddly screws in plastic fixings so I took an air intake pipe off instead) - it is ever so slightly rough on one edge compared to the other edge. Other than it looks in pristine nick.

Wonder whether to spend the ££££s and get it changed as a precaution or put some stuff on it to get rid of the noise? The noise is no worse than it was when I first noticed it a few weeks back.
 

·
Premium Member
Joined
·
23,737 Posts
Beltslip will get rid of the squeak though you should change it in the not too distant future.:-D
 

·
Registered
Joined
·
38 Posts
Ive had this for a while and now I get a whining noise, and flat battery quick check with the multi meter and now charging voltage at the battery..so looks like a dead alternator!!
 

·
Premium Member
Joined
·
23,737 Posts
Good news Beefy, now you can get back to enjoying the drive.:mrgreen:
 

·
Registered
Joined
·
2,042 Posts
Old neoprene belts were ok with a bit of belt dressing as a quick fix but need replacing asap.

Newer EPDM belts with belt dressing is not a good move , unless of course you want to make matters worse.

Belt dressing makes the EPDM swell massively and can cause the belt to derail - Not a good place to be !
 
1 - 20 of 20 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top