Tomorrow, during the snowstorm we're expecting, I'm going to get myself some snow tires and hope my old garage knows a thing or two about Jaguars.

Of the things I knew I needed to get addressed, the two things that stuck out the most when I bought the car were the clunk and the tick, and I'm going to have them both checked out.

The clunk is in the rear, right side. I'm beginning to think it's not related to the rear suspension, and may be the exhaust. All I know is something back there makes a clunk every so often when I hit a bump. There's also an intermittent rubbing/skidding sound that I hear when I accelerate from a stop while turning right at an intersection, or when I hit a dip in the road at speed. Something on the passenger's side of the car also makes contact with speed bumps if I take them faster than a snail's pace. I've crawled under there, but couldn't for the life of me see anything out of the ordinary. No unusual wear on the tires, either.

The tick is in the engine. I can hear it at idle, or when in motion - but only when accelerating. if I'm coasting, I don't hear it. It's linked to engine RPM, and it sounds like a sharp snap, so I'm convinced it's electrical in nature. I broke out the mechanic's stethoscope and poked the distributor cap, the coils, the amplifier, and a bunch of other stuff (mostly just for the novelty of it) but couldn't find the source of it. It doesn't seem to hamper the car's performance, and it hasn't gotten worse, so I can't say I'm too worried about it.

I'll also have to inquire about more sophisticated ways to remove stuck cassettes. I've heard butter knives and dental picks work alright, but I might just pull the thing and give it a once-over to see if there's anything that can be done about preventing this sort of behavior in the future. I'd love to keep the stock deck in. I know it's not the 1980s anymore, but it's just too cool to sit on a shelf somewhere... Unless it is totally broken.

 

The clunk could be all sorts of things, bad rear cage mounts, loose exhaust, generally it is the big trailing arm bushings though, they will twist and rotate and cause a clunking sound, my car is currently doing it.

The ticking is harder to say without more clues or info on where it is coming from. I would check all the ancillaries for ticks and the exhaust for leaks (which can sound like a tick)

As for the front clunking..how are your shocks? How are the bushings on the tops of the shocks?

 

+1 on the radius arm bushes.
Ticking could be the distributor cap arcing; run the car in the garage with the doors shut (not too long or you will surely die!) and lights off (bonnet open obviously) and you will see nice blue snakes crackling around if there is any arcing.

 

haha, they most certainly can crack!

 

I had a very similar 'Clunky/Banging' noise, especially when going over Road Humps, even at very slow speeds.

And so I spent the best part of a Week adjusting the Exhaust, as I thought that this might be Banging on the bottom of the Car, which to my complete surprise turned out to be exactly what it was!

Unfortunately this didn't solve the problem.

Which continued to persist up until the moment that I found the Shock Absorber Bushes missing as they had completely worn away!

In some ways this turned out a Blessing in Diguise as I made some up from Rubber that was harder than the OEM, which not only cured the Banging but my XJS now handles like a dream.

In point of fact I also got the Clicking sort of noise that you described, when starting off at Traffic lights and Junctions, which completely disappeared when I replaced the Shock Absorber Bushes.

And never gave those Bushes a thought, as She had just passed her MOT where of course they missed them but not half as much as the Car!

 

If the tick is the distributor cap, I'm the luckiest man on earth - I would think for sure that the current would have got me good when I poked it with the metal probe on the stethoscope! It'd be an easy diagnosis and easy fix if one of the terminals under the rotor was toast, though. Exhaust does make some sense. Not being used to the engine, I'm not sure how it should sound, so if something is amiss, I'm none the wiser. It certainly doesn't sound like I have a leak otherwise.

I'm hoping the clunk is something as simple as a worn bushing or broken exhaust hanger. Poking and prodding and jiggling didn't produce any results of note, so we'll have to see.

 

There are two exhaust mounts in the rear subframe (one for each side of the exhaust). It's hard to tell that one has gone bad without being under the car. Common enough for the exhaust to fall out of the mount, or for the rubber to have rotted away giving the pipes more freedom than they should have especially around corners..

 

yeah the dizzy goes pretty fast, not much fun to get zapped by a v12

 

Well I'll be damned - the clunk and tick are totally exhaust related. Loose hanger and a failing gasket.

Everything else checked out alright - "for an old car." Nothing moved that shouldn't and everything that should move did.

I'm actually kind of disappointed.

 

You should just leave it, will give you peace of mind. My GF's discovery has lots of exhaust noise because of a stupid joint design and its nice to always trick myself into thinking it is just the exhaust so I am not constantly worrying.
lol, no really though, being quiet is one of the best things about the XJS, definitely get it back to where it should be. Good thing it isn't something super expensive!

 

Don't worry, your disappointment won't last long!

 

That's for sure one thing I'm quickly learning is that Jag's eat $100 bills faster then a high class escort !

 

I'm sure the ROI with the Jag is substantially higher