Hi,

I bought an XJ40 a couple of month ago and I have noticed a clicking/tapping noise from under the bonnet. Using a stethoscope, the source of the noise seems to be coming from the injectors, particularly at cylinders 5 and 6. All injectors are emitting the clicking noise but the sound increases from cylinder 1 (most forward injector) to cylinder 6.
The noise is quite obvious when standing next to the idling engine. Behind the wheel, the clicking noise can still be heard quite clearly while at low speed the noise is faint but still noticeable below 30mph. As the speed increases, the noise is covered by the engine rev.

I am already planning to replace the fuel filter over the weekend and pour some injector cleaner during my next trip to the petrol station.

However, I would like to know whether this is a common problem (if that is indeed a problem) on the AJ6 4l, and if there is another fix beside replacing the injectors (~£350 for a full set I believe).


Cheers,

Nick.

 

as its gets louder as yer go towards the bulkhead, are you sure its the injectors?
there is a rubber pipe behind the dashboard which can harden with age , it then produces a clicking sound in time with the injections.
I'll have a look in me books and see if I can find more info on it for you.

 

its the force required to tighten it to spec

shouldn't this have a thread of it own?

 

Pay strict attention to the orientation of the bearing
halves, seals and spacers most importantrly the adjustable spacer which determines the
pre-load of the bearings on assembly. Assuming that the
correct spacer was used to set the pre-load on the last
assembly of the hubs on your car, you should be safe using
the same spacer with the new (OEM or equivalent) bearings to
retain the correct three thou pre-load.

Note too that the hub nut, is a one-time use only item and you are advised to use a new nut
on reassembly - using about 230 lbf/ft torque. A number of
people have re-used that nut - but it can be disastrous to
do so. The nut has a hardened steel thread insert to take
the huge torque and is a 'deformed thread' locking type nut
which will strip the thread if used repeatedly.

 

has anyone found anything on the fuel injectors, why they are ticking??? Any sulutions?? I have the same problem, just had a injection service done and didnt help..

 

Injectors are noisy, another reason jaguar and others went to engine covers with sound insulation. And not only do you not hear the clicking as the engine revs comeup, but you can no longer disern the clicks, theyre too fast...dont conjure up problems that arent problems youll go gray

 

On here looking for an answer to noisy injectors. The noise transmitted from the fuel crossover pipe to my ear via a screwdriver, is really loud!
Perhaps is just normal on the 5 litre engine. My 4.2 s/c and 4.0 s/c jag engines do not make this tappet tap noise.

 

I have never seen or heard of a 5.0 in the XJ40 sedan.

You should start a new thread instead of finding one over 8 years old.

bob

 

Hi Neville,

Please help us by telling us the year and model of your Jaguar with the noisy fuel crossover pipe.

I assume that the reason you were using a screwdriver as a stethoscope was to track down the source of a noise that is audible either from outside the car or from the driver's seat?

Cheers,

Don

 

to answer you question, yes 5.0 injectors are very loud and this is normal. they operate at 1000's of psi. you 4.2 only 45psi. not to mention the hipressure pumps are on the side of the 5.0 and they contribute to the engines noise at idle too. the injectors spring rate is much higher to open and close the pintle for such hi pressure where the 4.2 and others are weaker operating at non direct injection pressures

 

Wrong Forum! This is the forum for the XJ40.

FYI: The XJ40 was a sedan manufactured by Jaguar Cars between 1986 and 1994

 

HE WAS ALREADY CHASTIZED A FEW POSTS BACK....GEEZ

 

oh yeah? I didn't see any corrections, just suggestions ...go back to your own frorum and quit shouting at me, ok?

have a nice day

Larry

 

In post #9 Bob hinted that Neville was in the wrong forum, and in post #10 I asked for the year and model of his car so I could move his post and replies to the correct forum. I saw no reason to disparage Neville since he's asking a perfectly legitimate question and just needs some friendly help to get to the right forum.

Cheers,

Don