Advice required please V8 discovery crank noise

Hi all,
I purchased a 2003 discovery today on the understanding it had a "noise" from engine. Its a V8 ES model and on cold start its perfect but after the 50 mile drive home I can here what is discribed as bottom end tapping, it's not tappits as the noise is far slower than a tappit.
When I rev it a little it goes away?
The owner admitted running the engine low on oil, and so I decided to take a chance.

I think before it actually goes bang, I will like to get it sorted, can anyone recommend a local guy who is genuine.

And also as I'm sitting down, could you give me rough ball park figures for bottom end rebuild, I think its worth getting done as the motor as a whole is superb, the leather is immaculate, and most of the goodies seem to work.

Any advice here would be very well received.

Anyone..?

A new set of shells wouldn't break the banks, probably less than £100 with new sump gasket and oil pickup tube O-ring, assuming you do the spanner work yourself.

Bigger issue is whether or not the oil pump housing has been scored, that is alloy with the steel concentric rotor pump running inside. If that gets scored then the oil pressure will suffer.

I seem to remember that there is a take-off point for an oil pressure check on the block, might be worth confirming that it is low pressure, plus check the pressure relief valve isn't being held open by a bit of debris.

There are also other things like the crankshaft pulley being loose, flywheel/flexplate ditto.

Peter

Peter
that's is so helpful, thanks for taking time to advise me.

This is very interesting, I'm happy to get this done,and also the oil pump, see for me it did seem to be when oil gets hot, viscosity changes and pump struggles , when I rev it the noise goes (pressure increases)?.. Hmmm you could be onto something there, thanks again..!

as said previous bearings are fairly cheap £20-ish per set of which youd need 2 and maybe a crank polish or worse ,by the time you get knocking things are fairly bad and some more work is definitley needed

Not worked on a v8 , is it engine out jobby?
Or can crank be dropped out from below?

best with engine removed as crank cant be dropped out with it in but shells can be changed on the journal with some difficulty with it in

The tapping/nocking noise isn't there when cold, only when it reaches temp, when I drive it in sport mode and keep revs a little higher it isn't there, as soon as it goes to idle, then comes bottom end noise.

Any further ideas with this information.

Going to pop in to Aylmers tomorrow and get one of there specialists to have a listen.
Then hopefully we can look at getting it booked in.

Update:
My first visit to specialist showed no noise from engine, after driving back home it started so back I went and noise was very evident.
The initial thoughts are its from one of the rockers, so we are going to go the cheaper route first and change the oil and filter as its unknown, and then possibly get an additive in oil, oil pressure could be low after long running and thus starving the rocker or lifter possibly.
If no change, we will remove sump and check oil pick up, then stick a guage to show oil pressure on tick over.
If all shows nothing, then a strip down of rocker covers to show valve train and condition of rockers and lifters.

jamesmartin said:

as said previous bearings are fairly cheap £20-ish per set of which youd need 2 and maybe a crank polish or worse ,by the time you get knocking things are fairly bad and some more work is definitley needed

Click to expand...

Agree, work is definitely required now.