Guys,

Please excuse me for trespassing onto your forum for your help, I hail from the Land Rover pages - however, I feel that we are kindred spirits!

As I'm sure many of you know, LR fit the superb Jag AJV8 to the Range Rover (and the SPort, but we won't talk about that!) I'm not sure whether many Jag cars use the ZF box? But if it's of relevance the RR is fitted with the ZF6HP24, I know some Jags do use the same box...

I absolutely love the engine, I find it the perfect balance between performance and refinement. Far far superior to the BMW M62 engine the earlier years had.

Anyway, my propblem:

This is a really difficult one, no-one I've taken it to seems to know what it can be, half the people can't even hear the noise!

At 1900-2300RPM under load I get a noise that almost makes your ears want to pop. It sounds like a reverberation noise or intake related noise, but you can't feel it through the car at all. At that RPM under no load I get no noise, after 2300RPM the noise goes away and is soon replaced by engine noise. Road speed is irrelevant. It is specifically RPM AND load related. It "feels/sounds" as if it's from the front of the car rather that underneath me or behind me, so think I'm right to rule out the gearbox for now?

I've replaced the exhaust from the cats onwards (not inc the cats).
Replaced the engine mounts.
Replaced the main gearbox mount.
Removed and refitted the whole intake assembly.

RPM & Load = Noise
RPM No Load = No Noise

The only difference between those who scenarios is throttle/air intake, am I right?

So that is still pointing to some sort of intake noise?

What can I try next? Could there be an issue with the Supercharger? I've not heard of this problem relating to a failing SC before.

Worth noting that the car is relatively high mileage at 170,000 miles.

Dan

 

Take off the SC belt and drive the car (It won't hurt anything you just won't have any power). Report back if the noise has changed.
.
.
.

 

Thanks Tbird! It's a bit of a pig to do the SC belt, I might as well get the belt and tensioner replaced at the same time. Will speak to my mechanic and come up with a plan for driving it without the belt back on.

One problem is my mech can't hear the noise, although very competent - I think his hearing is shot!

 

"RPM & Load = Noise
RPM No Load = No Noise

The only difference between those who scenarios is throttle/air intake, am I right? "

Its not the only difference. The entire drive line is torqued up in one case and is coasting in the other case. But apparently nothing else draws suspicion in that direction.

 

Well until you run it without the SC turning you can't rule out the SC. If the noise does stop then you are pretty sure the SC is the problem.
.
.
.

 

Right guys, an update on this:

This evening I cut and removed the SC belt - up and down the road but the noise/reverb is still there. This is definitely RPM/Load dependant rather than speed dependant.

I've also replaced the tyres, all belts and tensioners/pulleys. I've had the car for 12,000 miles now and there has been no change in the noise.

 

You probably didn't need to cut it - if it's like my STR it has a sprung tensioner.

Our 4.2 with ZF 6HP26 (not 24) do not have the problem you mention so I suggest you try a forum for LR owners.

 

Thanks, it was cut to avoid 2 hours of labour to remove and then 2 hours of labour to refit after a short road test....

I have already exhausted the Land Rover forums, the engine is the Jaguar AJV8 - a great engine but the SC Range Rover was not overly common so even the Specialist LR garages have not worked extensively on these cars/engines. Hence me coming here.

It's re-assuring to know that Jaguars do not suffer from any noises. Thanks for your help.

 

dan_uk,
Jags DO make noises, and had you had a knocking suspension or irritating hidden trim piece rattle, pages of suggestions would've poured forth!


Possibly driveshaft or other drivetrain noise? Do you have access to a large empty parking lot you (and helper) could test same thing in reverse?

 

Agreed ....... but this thread is about a Range Rover.

Graham