Hi all sorry to be posting again but need more advice. I have a 3.2 XJ auto. The car pulls like new and each gear change is silky smooth and the kick down works a treat the only problem is that between 1700rpm and 2000rpm when at constant speed in 1st, 2nd and may be third gear there is an audible grinding sound heard both inside and out side the car. If I was to be at a constant 20 mph I will be in this dad rpm range and as long as I am touching the throttle you can hear the grinding sound, the second I come of the throttle the sound goes. Also if you accelerate at a normal rate or harder there is now sound. It is only when you are in traffic or have to accelerate super slow that you get the grinding sound. It is not from the engine, well I can not get the engine/ car to make the noise when in neutral or park, is only when the car is moving. I have changed all the pulleys and water pump ( not change the crankshaft pulley) any ideas?

 

The transmission on the 3.2 liter is a ZF4HP22 and not the 24

Behind the transmission is a driveline joint of a certain name that from reading others can act up

There is some rattle areas if you can differentiate that from a grind , or a ticking bearing

At the rear wheels there is a bearing that goes out as the output short shafts as the bearing is inside the center differental

I've heard that in person on another X300 and may be able to determain left of right side

 

Is it not the usual timing chain rattle? If not, the center driveshaft bearing can sound a bit like a grind at certain RPMs if it has loosened up too much. Check the jurid rubber coupling at the differential while underneath too.

 

So I have left the car over night and went to start it this morning, there is no chain slapping or rattling on start up, I can not get the engine nor the gearbox to make this sound when cold it is only after the car has been driven or engine is up to temperature that I can get the sound to come and go on command.
the next thing I noticed is that I was checking the gearbox oil but incorrectly, I was checking it cold and engine off not know that this is not the way to do it. I have now checked it hot with engine running and after selecting all position pausing for 5 seconds in each position and I am below the min hot level. Can I just top the box up through the dipstick tube?
can someone please tell me why when the engine/ box is cold why is my oil level above max cold but below min hot after I’ve selected all gear selections? Where does all the box oil go?

cheers all

 

You will want to top up the trans oil through the dipstick tube, but make sure the trans is actually hot. If you can drive for at least half an hour that should be sufficient. If not fully hot, you end up overfilling. Only add a bit at a time because overfilling is bad too.

Your original description of the noise is very much like the timing chain rattle of the AJ16. 1700-2000 rpm is about the range it is usually heard. And it will often only be heard under light engine load, but not in Park as you rev up. Its possible the sound could start as the engine oil warms up, since the chain tensioners use the engine oil. Could you record this sound and post it here? I have a clear memory of that sound (as many of us do), it is unique but hard to describe with words. Sounds like a moving chain dragging on an aluminum cover.

 

With the upgraded timing chain tensioner ( fwd high right engine block ) it will have a large arrow cast on it

The upgraded tensioner takes longer mound bolts

You can change your oil viscosity a bit and the timing chain is very robust , never heard of anyone changing the chain

03.1-09 (jagrepair.com)

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