Greeting All! I've been on these forums for quite a while, but mostly on the XJS group. A couple months ago I bought a 2003 XJ8, overall things seem pretty good but it does sometimes have a little squeak that seems to come from the idler pulley. It's not loose or rough, just a bit squeaky, so I ordered a replacement pulley from Rock Auto - Continental 49145. The part numbers and dimensions on the website seemed right, but now that it's here it seems wrong. The replacement has flanges on both side while the one on the car has only one on the front side. That would be fine I guess but the space between the flanges is narrower than the belt - I didn't install it but with just hand pressure the belt touches only the flanges, not the pulley which doesn't seem right. Probably not the original belt but it seems to fit all the other pulleys normally.

So what's going on? Has anyone else used this Continental replacement? Am I off base and it's ok for the belt to be wide like that? Maybe wrong part in the right box (pulley itself has no markings)? Any recommendations for another pulley?

And kind of a side question - should I be replacing the belt tensioner also? Or maybe just the pulley on the tensioner if that's available? 91000 miles, spring pressure seems quite strong still. I'd rather not since they are quite expensive compared to ones I've done on other cars.

Thanks, Eric

 

I'm new to Jags but looking at it online, that pully is definitely different and if you hunt around I bet you'll find it goes elsewhere on the front of the motor than where you're replacing. I see at least 2, maybe 3 different pullys under the listing "Idler Pulley".

I'd return what you have and recheck your original against the images on the rockauto website and get what looks like the right one...or figure out where this one goes and replace that as well since you'll already have the belt off.

From my experience of replacing just the one making noise, you're 50/50 that the tensioner will start making noise in the nxt few months. I would lean towards replacing at the same time, especially if you have to do any gymnastics to get them done.

 

Yes it definitely looks different than the others Rock has, but they don't look just like the one on the car either - I don't think that's necessarily strange though - the width in the specs listed seemed right to me but I guess it's the width including the flanges, not between them. And there's only the tensioner and this idler, everything else is driving something so it's not in the wrong spot.

Regarding the tensioner, I'm inclined to wait - the cost is approaching $200us vs under 50 for other cars I've bought them for. It's pretty easy to get to.

Thanks, Eric

 

The plastic idler (NCA2221AA) was used to VIN 878717.
Metal idler (AJ82266) from VIN F00035.

These part numbers are likely superseded.

 

Could be I just ordered the wrong part though this was listed for the model year / engine on Rock. The Jaguar part number I was using for reference was C2C22758, from Jaguar parts diagrams on the web. My car ends in F57753, 2003 with 4.0 v8, the pulley on the car is metal, don't know if it's original but looks like it could be.

Thanks, Eric

Edit: Looked around a bit more and it seems the number I used, C2C22758, was listed as superseding AJ82266. Rock listed both those numbers as oem / alternate numbers for their pulley.

 

I kinda remember possibly running into this issue as well, I believe what I did was return the pulley and I just replaced the bearing in the pulley. It's worth a look, just remove the pulley and you may be able to press the bearing out with a bench vise and a big socket

 

that's the double flange pulley for late 4.2s it only has enough space for a 6 rib belt

you can use smooth 89016 pulleys in the bracket mounted idler even on old plastic pulley cars

 

So, I haven't checked in for a few days due to work etc, but did order a Dayco 89016 pulley from Amazon - it had the same part number cross reference and sizes as the old one, but no flange on the front - (just like lots of other idlers I've seen). Put it on this afternoon and immediately when starting the engine, quite a lot of noise. When I looked at the pulley, I could see that the belt was tracking toward the front of the pulley, and had actually climbed up onto the front flange of the alternator pulley about 3/32". I thought I might not have aligned the belt right when I put it back on so loosened it and made sure it was right - same result when starting the engine. I took the pulley back off and reinstalled it even though there isn't much to possibly screw up, same result. Ended up putting the old pulley back on - much better. I was replacing it because it was squeaking sometimes, and still turns smoothly so should be ok for a while.

I'm pretty puzzled by this - I'm sure the pulley was on right, that's really simple, and I've had other vehicles with smooth pulleys like the Dayco that worked fine. All the other pulleys seem straight, not loose, and lined up, and just by looking at it the Dayco pulley seems normal with all the dimensions about the same as the old pulley. No idea what's making the belt go off track. I'm thinking now I'll bite the bullet and buy the (much more expensive) Jaguar part next.

Thanks for your help, Eric

 

odd. I replaced mine with a smooth no lip pulley and have had no issues whatsoever. Perhaps there is a misalignment somewhere else that is just compensated for by that lip?

 

the metal pulley 308 isn’t supposed to have a flanged idler as a replacement piece anymore. uropoor sells the smooth C2C22758 with the centering bolt or you can pay the dealer 5x more.

i know what you’re talking with the belt jumping around and it only happened to me on an x350 that had the discontinued c2c5093 single flange (your pulley). the bolt it came with messes everything up if you try to use a standard pulley pretty much

 

Some info from Jaguar about the FEAD.

 

I'm starting to think so - maybe the noise was belt vs pulley flange and not the pulley bearing after all.

 

I had read that about the smooth pulley being standard now and the Dayco one I got looks about identical to the pulley on the tensioner. I hadn't heard anything about the bolt causing problems though, it seems like that pulley is located by the bracket more than the bolt.

 

Thank you very much for those service bulletins Motorcarman! I did install the belt as that bulletin recommended and I'm quite sure it was on correctly until the engine started, so it looks like the tensioner may be the culprit and not the replacement pulley I have. I guess it should be a lesson to me about trying to do this stuff cheaply - the last time I replaced an idler (on a different car) I ended up replacing the other idler and tensioner within a few months - it cost more and way more hassle than doing it all at once. Maybe I'll learn this time.

I'll check the ac compressor too though it seems like any alignment problem there would be isolated by the other flanged pulleys between it and the idler.

Anyhow, the bulletin said the tensioner was revised - do you know if it was a wear issue or design issue, and is there a way to know if I'm getting the new or old design?

Thanks for your help! Eric

 

Well it took me a long time to get to it but put the new tensioner on today along with the smooth replacement idler pulley I tried before. I had doubts because the new tensioner seemed almost exactly the same as the old one, and same part number on it, but the belt seems to be tracking right now, at least just idling in the garage. I'm hoping its good out on the road too.

Thanks to all for your information and insights!

Eric

 

Here's an update - hadn't driven much since changing the tensioner as I was out of town. When I returned there was a noise on startup, but it stopped before I could open the hood to check. I had put the old belt, which was a bit frayed from derailing, back on because I didn't want to wreck the new belt if things went bad. Put the new belt on yesterday thinking the noise might be from the old belt damage, noise was stronger and before I could shut down the belt flew off, so back to the drawing board I guess. I put the idler with the lip back on again and it's ok for now.

One of the bulletins Motorcarman was kind enough to post said to check the a/c compressor mounting bracket, so that's the next step, but it might be a while due to other obligations.