4.0 P38 Air Filter Box Noise

My 51 plate p38 has a popping noise from air filter when rev'd up(not gassed up).It is lacking power and has a miss fire,we have replaced the following.New plugs,leads and crank sensor(been on diagnostics to be told crank sensor at fault),replaced down pipes(as some clowns cut the cats out).Had gas anylaser tube up its pipe and it has no issues with emmisions.Had the engine compression tested and all cylinders achieved over 175 psi easily.We have had the coil packs checked and they to are ok,very fustrating,any ideas boys(or girls)?

Hi i'm new to Range rovers but my experience on other cars would indicate timing. Usually if a car backfires into the inlet side of things its because the timing is out.....i could be wrong and prepared to be corrected but if you checked everything else this could be something to look at.

Thanks for the reply,but i have been told the timing is none adjustable?ECU controlled,but they could be wrong.
Cheers.

Hi there,
did you solve this issue? I am currently having the same fault with my 02 plate p38.
Suggestions so far are either a coil pack or head gasket failure.
Thanks

Hi,
The p38 has known isues with Bosch ignition leads.

This ones worth a try even though you have new leads.

Wait till its dark and look under the bonnet, cover any illumination and look for arching. Also check leads for chaffing or crossed leads, also check ends.

This link may help

coil4


Good luck

Fred

Hello again,
its just had brand new plugs and leads,all originals from landrover.A little experimentation with the plugs reveals that the plugs causing the fault are 2 and 4 (rightbank drivers side).No 2 is badly sooted and when left disconnected stops the blowback throught the airbox.There is compression on all cylinders.

Brand new sooted no. 2 plug.

Is she running on petrol only?

Definitely one for the engine guys

Good luck

Yes Petrol only no LPG (yet).

Ok replacement coil pack fitted still has same fault.Compression test on all cylinders are 150+ on each cylinder.
Arghhh

myolford said:

Ok replacement coil pack fitted still has same fault.Compression test on all cylinders are 150+ on each cylinder.
Arghhh

Click to expand...

Poss silly sugestion, have you tried cleaning air flow meter? ten mins with can of carb cleaner!

I did mine recently and theres a huge difference in performance/driveabilty!

may be worth a try?