Hi everyone,

I just bought my first car and it was a 2001 Jaguar xjr. When I bought the car it had 105k miles on it and it still had its original timing parts and because I like to tinker and I was worried about the loud tick when it was cold, I decided to replace the secondary tensioners and when I got the valve covers off I saw a lot of cracks in the guides as well so I decided to replace guides, chains, tensioners, and spark plugs.

I just got it all done last night and when i first fired it, it came right to life and ran good and as it started to find itself and lower the idle I noticed a loud tick and I got worried and consulted a mechanic and they assured me that everything went well and the tick may be piston slap or a lifter issue.

I got the car up to temperature and it seemed to be running great, no tick and smooth and powerful so I am wondering if anyone else has this tick and if they may know exactly what it could be?

thanks for all the help.

 

Not knowing how long you had it running before the "tick" went away, it sounds like the motor was just getting oil into all the journals and up to the cams and chains.
Listen again at the next cold start and let us know.

Just curious, did you drop the oil pan and check the oil pickup for any obstructions?

 

+1 on highhorse's comments. These engines will make some noise as the oil pressure comes up. I always let the rpm's go below 1000 on a cold start before putting it into gear. I even tell valet attendants to do this before handing them the tip !!!

 

I’ve put a few miles on since doing the timing and it seems to tick on every cold start, maybe 5-6 cold starts(I also mentioned it above but just to remind you, it made this noise before) it seems to be coming from the center of the supercharger almost underneath it. My mechanic friend stopped and listened and said that it sounds like it’s coming from the fuel injectors but he wasn’t sure why they’d be ticking. It also seems to disappear as the car warms up a little or if you rev it above 1000 rpm.

I didn’t take the oil pan off and check the sump, maybe I should?

 

could just be the usual supercharger tapping noise

 

I’ve never heard that issue before, is it alright or something that should be addressed?

 

eventually it’s gonna get louder as more annoying but you can put it off for a long time, when you have the blower off to change the coupler it’s a good time to upgrade upper pulley, maybe new snout bearings and and quicksteel the silencers shut

 

Could be your SC coupler, if you do replace yours (its 20 yrs old after all, won't hurt), you want this one, not the green solid one... https://www.ebay.com/itm/New-OEM-Eat...YAAOSwvyxevE4i

 

Interesting, I’ll do some research on it and think it over. It doesn’t seem terribly expensive and it would be some peace of mind. Thanks!

 

You could take the supercharger belt off and do a cold start. If you still hear the ticking noise you can rule out the supercharger as the cause.

 

I have exactly the same ticking from my AJ26 SC engine (1999 Daimler Super V8). It sounds like it comes from the supercharger, or from one or two injectors, or cam shims/followers on the left head. In my case, it is not from the supercharger as it was still present when I removed the SC belt. The ticking gets quieter as the engine warms-up and completely disappears at 88C (I have a digital temp gauge installed). Before that, it stops if I rev the engine to some ~1,200 rpm.

I have listened to the injectors with a stethoscope but they do not seem so loud to be able to produce the ticking heard from the engine.

One thing I noticed is that the ticking appears to be initially twin, like "ta-rak, ta-rak" and, as the engine temp reaches about 80C, the ticking slowly changes to a single "tak, tak, tak" and soon disappears. I therefore suspect that it comes from two valves on one cylinder (exhaust or intake) having slightly bigger shim clearances, one a bit more that the other since one seems to stop ticking earlier than the other. I have bought the special tool for shim replacement in-situ and I intend to check all valve clearances and adjust if necessary but I am not in a hurry as the engine sounds perfect once warmed-up.

Otherwise, I have recently rebuilt my engine - replaced the heads with very good used ones, everything new in the cam timing area, new cam followers etc. and adjusted the valve clearances as best as I could on the bench. However, as I did not have the exact required thickness of a couple of the shims at the time, I put in the closest I had. Perhaps those are the ones now ticking. Jag engine seems to be very sensitive to the valve clearances as the shims were initially made in just 0.02 mm (haven't seen this small increments in any other engine) and the increments were later revised to even smaller steps of 0.015 mm.

Another thing is that the sounds from the camshafts area seem to be somewhat amplified (or not muffled) by the plastic cam covers.

 

Reply to M. Stojanovic,

Crossing my fingers, I’ll have to test it by taking the belt off and firing it up. I sure hope the noise is just the SC coupler though. If it was the same issue as you would that require pulling the heads or could I just shim something at the cams.

Actually when I cold start mine it’s not noticeable as it has high rpms upon start up, but once you shift it into reverse or drive it really starts to tick.

also Im surprised that I can start the car without the supercharger pulley on, wouldn’t that mess something up?

sorry for all the questions and thanks for all the information.

 

Same in my case - no ticking during the initial warm-up stage when the idle rpm is held higher by the ECU; then, after idling for a while and the idle rpm is brought down below 1000, the ticking starts; if I rev it to just above 1000 at that time, or any time later, no ticking; the ticking completely stops at 88C and above.

You don't remove the supercharger pulley (not easy to do anyway), just take out the supercharger belt. No problem starting the engine without this belt (SC not running).

To replace any shims without removing the camshafts, you need a special tool:

It is tool No. 303-540 and currently seems only available from Bosch Automotive Service Solutions (https://jlrequipment.service-solutio...px?SKU=303-540). I got it from them, made in Hungary, by the way.

You will also need a set of feeler gauges in smallest increments you can find. I bought the shims that I did not have (at the time of heads rebuild) from SNG Barratt.

 

Reply to M. Stojanovic,

I believe I may be in the same boat as you. I removed the supercharger belt and the ticking remained.

So I guess my next question is, is this something that should keep me from driving the car until it’s fixed?

 

M. Stojanovic,

If you have some shims for an AJ26 that are to thick and provide very little clearance, you could possibly take them to a machine shop and have them ground down to a desired thickness? Just an idea. I have a feeling that the shims you used provided too much clearance seeing as the noise goes away when up to temp.

Kroeger
I don’t think it’s an issue to keep driving it that way. Should it be?? Not really, but if you have to ever do a set of head gaskets, do yourself a favor and let a reputable machine shop take care of all the machine work and pay the price to be done with it. It’s such a pita!

 

I hope the ticking is due to some incorrect valve shim clearances - I will know when I decide to have a go with my special tool (I now have all shim sizes ready, in 0.015 mm increments). However, it may be a kind of "mysterious knock" (to do with the engine design?) as others have also reported it and I have not seen a solution posted by anyone. I interpret the fact that the factory went from initial 0.02 mm shim increments to 0.015 mm increments (for the engine, I presume, very sensitive to valve clearances, causing ticking if not perfect) was due to difficulty setting the valve gaps accurately so that they don't produce ticking thus even finer increments of the shims were necessary.

To replace valve shims, you either (after reading the existing gaps):
Remove the camshaft(s) - done in-situ but quite a bit of work, or
Use the special tool No. 303-540 - requires only removal of the cam covers

Otherwise, I have been driving my car for now about 2 years (having the cold ticking) with no issues. The ticking warm-up "pattern" has not changed in any way (not getting louder nor lasting longer than 88C) so I am not concerned at all. And the engine runs perfectly smooth when warmed-up, that is why I am not in a hurry to go over the valve shims.

 

Just an update

I have driven the car probably 1000 miles now and the ticking seems to be staying the same so I am pretty sure that it is just what you said it is m. Stojanovic.

However last night I was scrolling through the forums and just reading stuff and I saw one guy said that the crankshaft sprockets had to be offset a tooth and I didn’t know that, I believe I put them back correctly but if I didn’t it would be pretty obvious right? Also my primary chains were really tight like I couldn’t even fit a shim in between the guide & tensioner.

also I’ve been meaning to post my trick to getting the crankshaft pulley bolt off, what I did was take a very large pliers (20.25”) and I placed that on the two raised sections of the pulley between the regular belt and supercharger belt and with two people we could take that bolt out pretty easily.

 

Don't use that method again. The pulley is not solid but it has a rubber segment between its centre and outer parts as it is also a harmonic balancer. Holding the outer part of the pulley may shear the rubber segment (a new pulley is USD 1,800). You may have been lucky as it seems that your centre bolt was previously not tightened to its full torque of 375 NM.

You may remove the bolt using a powerful impact gun (don't hold the crankshaft using the locking pin for setting the camshaft timing in any case) but to torque the bolt you need this tool which holds the centre part of the pulley:



This is for SC engine pulleys. For NA engines, the large spacer is not needed.

 

The crankshaft sprocket is one-piece, so the offset is already there. You didn't mess up anything.

 

The crankshaft sprockets are two separate parts but, as they are the same part number, they can be installed in a way that their teeth are aligned. If the teeth are aligned when installed, one sprocket needs to be flipped-over in order to have the teeth offset as required.