Been a while since I've been on the forum but I've got a quick question. My 99XJR has the bad chain tensioners evidenced by the distinct rattle at startup. It has been just a second or 2 at the first startup of the day and no more. I recently replaced the top tensioners but didnt do the bottom since I didnt have the time money or tools to do it properly. From that point it was the same, just a second or 2 of rattling at startup. That made sense bc the tops were in great shape. I noticed the rattle hanging around a lot longer now, sometimes up to 30 seconds or more. My question is what grade of oil do you think may help a bit if at all. Any additives that may help? I know I need to replace them but I cant now and the car is only driven once a month currently. Thanks

 

no oil will help. you need to confirm where your rattle is coming from, if it's from the chain you'll have to do the primary stuff

 

thanks. It is from the primary. I know the primary tensioners, chain and guides need replaced. It's on the menu just cant be done now. I only ask because sometimes you can help an issue "not fix it" by changing oil. For example old worn engine with low oil pressure may be "helped" by a higher viscosity oil. Wont fix it of course but may help. Just wondering if anyone tried or heard of something that may help the tensioner achieve pressure quicker

 

If the plastic guides are bad enough, maybe there’s chunks in the pan that also clogged the oil pickup? It would be beneficial to take the pan off and see.

 

No point in trying to cure the symptoms and not the cause of the problem. It is actually better to hear the rattle and monitor whether it is getting worse and worse. If you mask the rattle by, say, thicker oil (unlikely to actually work) you won't know what's happening with the tensioners until suddenly something goes very wrong ($$$$). Better not to run the engine until replacement of the tensioners, gudes and chains.

 

thanks all. I did plan to drop the pan and check the pickup with the oil change. I understand what u guys are saying also about not masking the problem. Trust me I want to do the job. Just dont have the time or money so I'm trying to buy a little more time. Last question - can u point me to write ups or videos on the chain/guides/tensioner job. I have to decide if I'm up for it or if it's time to say goodbye. Thanks

 

This is a link to a forum thread that started off as a "jack stand" question, but lead to a pretty extensive timing chain tensioner upgrade saga. It has some good information and is worth looking at.
https://www.jaguarforums.com/forum/x...points-229673/

And this is a link to an excellent write up by BlackOnyx with a blow-by-blow account of the job...........
https://www.docdroid.net/2ZOPQDm/x30...eplacement-pdf

 

WWilson, my 98 xjr started getting a nice tick. After pulling the cam covers, Secondary tensioners were perfect, issue was a stuck primary. Once I got the timing cover off, All the chains and guides were perfect. Replaced all the chains and guides (primary/secondary), most likely could have gotten away with just the bad primary. the 98xjr had around 180k at the time. Another possible source of noise is the supercharger; very common for the flex joint and needle bearings to wear and make a clunk/tick/rattle.

 

Thanks all for your replies. Definitely some useful stuff. I spent 2 hours reading through that thread that started about Jack stand points. Didnt seem too bad for the guy that took it on and worked on it pretty much daily. But for a guy with a job a side business and 2 kids it sounds like a **** ton of work that I could only get to maybe twice a week on late nights. Also mine is SC, are there no differences in the parts kit, special tool kit and the overall timing chain process other than the obvious (metal coolant pipes Instead of plastic for example)?

Anyway I dropped the pan to see what we got and found no metal but 2 pieces of plastic likely broken off of the chain guides (see photo). So I know they're in bad shape.

Anyone have a good link to head gasket write ups? I know this thing could use them since an overheating issue in the past was solved with blue devil head gasket sealant.

Thanks

 

It definitely is a fairly major job, especially done in a home garage with no lift. You do have to get underneath the car to install the crank positioning tool.

I believe the SC harmonic balancer tool is a little different, it is deeper than the one used for the NA.

The SC does not have CVVTs, those units are fixed on the SC, but that doesn't really make much difference to the job.

It took me about 20 hours to do my NA, you would add extra time to remove and replace your supercharger. Once you've done one, you could do another in about 15 hours, and probably a third in about 12 hours.

You do need a second pair of hands to help remove/replace the hood.

With seeing those broken plastic pieces in your pan, I wouldn't dare start that car until the tensioners/chains were replaced.


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I've done both SC and NA engines. Definitely have the cam and crank locking set. The harmonic balancer removal tool will work with both but you might need slightly longer bolts with the SC engine. I've been able to do it without removing the hood. Two guys come in when removing the the harmonic balancer and tightening as technically your supposed to brace the torque converter with a pry bar and not rely on the crank locker.

You will need a 22mm or 24mm socket (can't remember which) for the crank bolt and torque wrench that can handle a LOT. I can't remember the exact specs but the balancer bolt has a very high torque spec. Also remember on the primary tensioners if replacing plastic with metal you no longer need the metal backing plate.

Tons of small bolts, electric or air wrench highly recommended.

If you are going to tear down that far I also recommend replacing the coolant hoses under the SC and taking off the intercoolers to clean any carbon/oil buildup.

 

Removing the crank pulley/balancer can be a major pain. Not only removing the (very tight) cetre bolt but also pulling the pulley off the crankshaft. To do this properly, you need 3 tools:

1. Crank pulley holder, to remove and later torque the pulley centre bolt - in no case you should hold the pulley over its belt grooves but use the special tool; the one for NA engines won't do, you need a much deeper one like this:

2. Pulley puller - in no case you should pull the pulley on its belt grooves or anywhere on the outside; use this type of puller that screws into the pulley's threaded holes around the centre bolt (same holes to which the pulley holder is attached):

3. Torque wrench that can do 375 Nm (277 Lb.ft). Such torque wrenches are about 32 in. long.

When undoing the pulley bolt and when torquing it, make sure the crank locking pin and the camshaft locks are not in place.

Pulling the pulley off the crankshaft may take quite some time as it sits very tight and it uses a locking ring tapered in the opposite direction than usual. Just pulling the pulley actually tightens its sitting over the crankshaft. You need to tighten the pulley puller hard, hit it in the centre, release it a bit and hit the pulley like back in again, tighten the puller, hit, release a bit...and so on, probably need to repeat this cycle many times.

 

I want to thank you all for your willingness to help. The info you provided is priceless because I don't know where I would have gotten it otherwise. So I know I cant do the job now but I'm going to attempt it. But for now I changed the oil, cleaned the pan and oil pickup which had lots of crap In it and I decided to risk it and start the car. It went well and it rattled for less than 2 seconds - a good result. The way I understand it is the time its rattling is the most dangerous time as there isnt sufficient tension on the chain and that's where it's more likely to jump teeth. Once the rattling has stopped there is now tension on the chain and catastrophic damage is less likely but of course not impossible. So I'm gonna try and drive it a few miles at low rpm to a garage where it can sit for the next 6 months until I can tackle it. Hey have any of you replaced your head gaskets? Looking for Info on that. Maybe I can tackle both in 6 months.