I recently discoverd an issue with my 2004 Jaguar X-type 2.5 manual with 62k miles. It sounds like a faint knocking during acceleration in 1st and 2nd gears. I am at a loss of why this is happening (I always use 93 (premium gasoline) in the car). Any ideas and a solution to the issue?

 

akhanaa, does the knocking get worse if you are turning? If so, then you may be experiencing a bad CV joint. Does the knocking occur at all RPMs or only in a limited range? Does the knocking occur if you rev the engine with the tranny in neutral? Does the knocking occur if you accelerate hard when in 3rd (or 4th) gear?

If the noise is only occurring when in 1st/2nd gears, then I would be leaning towards a chipped tooth in the tranny. What you are hearing is the gears meshing with the space, creating a change in sound. This can be caused simply by not shifting properly once and grinding the gears or could simply be a weak gear and you managed to chip a tooth. If you are getting the sound in more than only 1st/2nd under hard acceleration, then I would be leaning more towards the transfer case. But then, could also be a sticky lifter or something else internal to the engine. Without hearing the noise, it is hard to say what it could be. Something even as simple as the knock sensor going out could cause something like this. But then, normally if the knock sensor is going, it will toss a code too.

 

engine knock ( pinging)? drivetrain knock? suspension knock? please be a little more specific.

 

I first discovered the sound when I was traveling on a straight stretch of road with the windows down...slowed down for a speed bump in a residential neighborhood went over the bump slowly, put it in first gear and hit just over 2200 RPM's and heard the knocking noise......shifted into second and then heard the knocking again (around the same RPMs) and then it stopped after shifting into 3rd.

In attempt to isolate the problem I have parked the car and revved the engine gradually to about 2500 RPMs and didn't hear any knocking.....additionally giving it a spike on the gas pedal a couple of times...but heard no engine knocking sound.

 

akhanaa, based on what you are describing, that is sounding like something more than likely inside the transmission. No garantees on that, but since you only hear it in a few gears, it is leading me to believe this. If it was the engine, odds are you would hear it in other gears and/or when revving the engine. The CV joints tend to make noise at all speeds and tend to get louder the faster you spin them and especially make noise when turning. The transfer case would make noise in any gear, same with the driveshafts. So, through a process of elimination, it seems the chipped gear tooth is your most likely suspect. But, this is also by no means the end all diagnosis. Your best bet would be to get a fluid change done on your tranny and see if they mention anything about lots of metal flakes/chunks when changing the fluid. That would confirm your problem. But, if they don't find anything, then I would continue to look. There is something going on, I'm just not sure what.

 

I'm noticing a similar noise on my 03xtype. clunking, ticking snapping noise between 20-30mph. It doesn't happen if you keep it in 2nd, all other gear selections it makes the noise.


Did you ever figure out a solution to your problem?

 

I found all the allen head bolts ready to fall out of the drive shaft front universal joint. After torqueing them to 40nm about 90% of the noise is gone after driving about 20miles. I suspect the remaining noise is due to some damage done to the universal joint and or alignment issue of the driveshaft.