Hi Guys, i just introduced myself to the forum with my nice 95 xjs,

i got the car from the states, it has been driven and maintained regularly , according to the invoices and talks with the previous owner. after a week of driving i decided to go to a jaguar specialist here in the netherlands, to look at the status of the car, change oil, have him do some small stuff. when i got the car back, everything looked fine.
until one morning i wanted to go for a drive, and after 1 minute the car started ticking very loud, from the lower side of the engine. i stopped immediately , and drove home. i was just around the corner. i checked where the sound came from with a small microphone and noticed it was coming from the lower passenger side of the car, near the automatic transmission.\the roadside assistant thought it is a crankshaft bearing, and also did my mechanic. but the strange thing was that at the garage, they did hear the noise, but it disappeared after some hitting the gas pedal. and did not come back. also not the next morning, when the engine was completely cold again. it sounds very smooth again.until now, they couldn't reproduce it.
what can this be? any idea? the thing that changed since it was brought to the mechanic, was that they put in other oil, 10w40 in stead of 20w50 that was in it, but this should not make any difference should it? also did they replace a thread because the valve cover was leaking some oil, so they drilled in a new helicoil. i read that the aj16 is very strong and dependable, especially the lower part of the engine should be indestructible. also my mechanic had never heard of any problems like a crankshaft problem with th aj16.
it has had very regular oil changes, 120000 km, so it should not be like this. obviously i hope its something else, like a loose screw somewhere...

ca they take of the oil pan easily to have a look at the bearings? or any other suggestions are welcome

thanx, pim

 

Forget the bearings, for sure it is not them! Just drive the thing and have fun, this will be something entirely innocent. The engine is bulletproof.

 

Hi greg, thanx for answering;

the sound was so loud i was really thinking the engine would certainly not survive if i would use it like this.
even my neighbour on the other side of the road looked up and reacted... something much louder than bad ticking valves. I looked at some online movies of worn crankshaft bearings; and it did sound like that. Also it was coming from the spot where the crankshaft goed into thr gearbox. The only difference was that it dissapeared. Im ready to start using it again if the sound does not comeback but then i would need a plausible reason for the sound, and i cant think of one yet.. if it eould come back during a trip i have a problem i guess...

thanx, pim

 

Something maybe got stuck onto the flexplate and made the noise. A tiny chip off a starter ring tooth, a bit of grit, etc etc.

 

You are LHD, correct??, soooo the passenger side is the LH side,OK?

The exhaust on these engines is well documented to make a LOUD clicking/clacking noise, especially where the pipes joint, called a flange.

Cold = bad, and disappears as it heats up, sometimes never to return, sometimes it does.

The 4ltr, being a USA car will be 4ltr, is also well know for cracking the exhaust manifold castings, and that "crack" can be LOUD, and often it will seal up with carbon.

I agree with Greg, these engines are TOUGH< and apart from running ot of oil, or serious overheating, will not stop easily, or fail prematurely.

 

Hi Grant, thanx for your input, its being appreciated!
I'm afraid the sound clearly came from where the bottom of the engine goes into the gearbox. I put a very small microphone on a stick, (im into tv business) put my headphones on and wiped the engine, and the sound was clearly coming from the spot as much as possible into the lower corner of the gearbox/engine. if the sound disappeared again, would you say its not possible to be a connecting rod bearing or crankshaft bearing? i sure hope so. the mechanic is driving the car for a couple of days and is hoping we can reproduce the sound. if not, we probably won't do anything, and check the oil filter for debris. also he suggested looking into the oil pan, which might be not that easy because of the subframe.

thanx, Pim

oh yes, before this, i also had a different noise coming from the back (which now i will start solving later obviously), when i make a slow sharp turn, there's a 'rubbery' sound coming from the back. as if the tires were touching something. the mechanic also noticed it vibrating a bit when the sound occurs. both on a left and right turn it occurs, same sound. it has a limited slip differential, and there was a bit of play when you put your hands at 12 and 6 on the rear wheels and push with one hand and pull with the other, so not both hands in and out, but according to the mechanic certainly not much. the car drove approx. 120000 km ... any idea? wrong oil maybe? not limited slip oil in it now?

old cars.... love them!

Pim

 

OK,

I reckon you have a flex plate cracked, the round "flywheel" looking thing the torque converter bolts to, very rare, but it can happen.

OR

The torque converter bolts are loose, rare again.

Rear end:

Get him to grease the 4 grease nipples in the half shaft uni-joints, Then try again. They are soooooo forgotten, sadly.

 

Could it be a cracked exhaust manifold or maybe just a manifold gasket blowing ? I have tried the gasket failure on an AJ6, and the sound is quite strong and 'sharper' than you would expect from an exhaust leak.
A crack in the manifold could probably be tight when warm and leak when cold

 

Hi grant, that is exactly what he decided to have a look at; if the torque converter bolts got loose... And the rear end, he did talk about some nipples he greased, but i will ask him which one exactly...

I will keep you guys posted!

thanx a lot, pim!

 

He found them, there are ONLY 4 on an X300 based XJS, well done mechanic.

 

Yes he found them; but the sound is still there... differential outside bearings maybe?

thanx

 

Bugga, maybe, they are an issue on some.

Suggestion on that "ticking"

While he is in there, drop and refill the Auto trans fluid, do it again after 50kms, and again, and again, until what is coming out is the same colour, or close to, what is going in. No need to remove the pan, simply drain what he can via the filler tube connection.

Stale trans fluid in these "electrckery" trans units can cause weird stuff, and fresh fluid works wonder. Same for the power steer system.

Oils is cheap, parts are not, Aussie phrase from the '50's, and worked for me for that many years.

 

Can you record a video and post the noise?

 

thanx for the suggestion; i will let him change trans oil.
i am not able anymore to post a video of that ticking sound, since it has disappeared and never came back. the car is in the garage, and the mechanic is driving it regularly right now. i'm abroad, so had him test it for a while.
he told me yesterday it runs perfectly, no strange sounds anymore. but when he first got it, he thought it sounded exactly like a crankshaft bearing, also the roadside assistance thought it would be that. after revving the engine a couple of times, the sound was gone.

he checked the flex plate and torque convector by looking at it as good as possible, and saw no strange things. its a mystery to me. you can imagine its a bit scary to just continue driving with it right now. i don't want to blow up the engine. but since the sound is gone the mechanic is also not capable of diagnosing anymore, and can't just start replacing expensive stuff... any more suggestions?

thanx, pim

 

Pim,

The mysteries of the Internal Combustion Engine. Bigger than teh WWW in total.

Many of my Jags, and I go waaaay back, made odd noises at times, and I kept on motoring. I have never seen a Jag engine fail, apart from stupidity of running out of oil/coolant, which you cannot blame Jaguar for.

Worst was my old MK7 (back in 1971), started a strange snarling noise, I was at about 100mph at the time, 400KMS from the nearest anything, unsealed Aussie highway, and decided to keep going. Slowed to 70mph for about 20 seconds, gauges all stayed OK, and the noise stopped, back up to cruising speed, and to this day I have never found what that noise was, and I still have the car.

Wifes Series 2 V12, nudging 650000kms, and untouched. Noises come ,and noises go, but it keeps on motoring.

If your mechanic is driving it around, and it is behaving itself, drive it, enjoy it, and IF it ever goes 'bang" worry about it then.

 

Drive the wheels of the thing! The engine will not fail.

 

Hi all; i got the car back from the mechanic; he drove it for 150 kms and the sound did not come back any more.
I drove it for another 300 kms, without strange sounds or problems. i had the mechanic also change the tires (they were not perfectly round anymore) and he changed them for new tyres with a slightly less outside diameter,(although same inch) it had those 'balloon' kind of tyres that look great but did hit the inside of the front wheel arches when i did a sharp turn.Also he changed differential oil, and now i also do not hear the strange rubbery sound from the back anymore when i make a slow sharp turn. i wasn't able to test that very well but it looks like that also disappeared.
Its a hell of a difference to drive with perfectly round tyres (strange, no?) and new brake discs. it behaves like new now. So i'm following your tips and just start driving it and try to get some trust in the engine... Shouldn't be too difficult..!

thanx for the help, if it fails, i'll let you know.
Pim

 

Tires- yes these cars are sensitive to tires. A couple of years ago I got some cheap Falkens because I figured, the XJS gets driven once a week (weather permitting), I don’t need expensive tires. I was really wrong on that. I just went back to Pirellis and it’s a world of difference