1999 Patrol 2.8 Diesel...weird running...any thoughts?

[Mjtray]

Hi

I'm based in the UK and have a 1999 2.8 TD Patrol with 93,000 miles on the clock....i've recently bought this Patrol, having had others in the past.

This one is doing something weird....when you drive it, there seems to be a rythmic surge to it...ie when accelerating or just driving on a light throttle, the engine will be lovely and smooth and then 3 seconds later you will get a diesel rattle, back to smooth, then 3 seconds later a diesel rattle and so on. When the rattle happens the car will lose a fraction of acceleration so you get this very slight surging sensation.

When I followed the car being driven by someone else, I also noticed a puff of black smoke every time it gets the diesel rattle.....I'm assuming that the rattle is potentially being caused by it overfuelling, which probably accounts for the black smoke.

Any thoughts on this.....a mechanic I know who does nothing but Land Rovers thought it may be a split vacumn hose and the surging is being caused by the injection system coming upto pressure, then loses it, comes back upto pressure, loses it etc etc and when it loses it, it momentarily over fuels.

Any help or thoughts would be much appreciated.

[Thirsty]

Possible air in the lines. might be worth a bleed, when was the fuel filter last changed? also clean your maf. Clean the intercooler and check your air cleaner. If that all fails, get the diesel pump checked.

Cheers

[ThePup]

G,Day mate my 2.8 was doing excactly the same. I started going through the obviouse things but couldn't find the problem. Then the motor died. I'm not sure if it was the problem with the surging or a second problem but have a look at your bottom pulley the one that comes off the crank. mine was flogging around. The harmonic ballancer sits behind this pulley and I wonder if that why it was surging. I could be wrong. Good luck.

[Radmobile]

Did u fix the problem? My 2.8 is doing exactly the same, I'll look into air in the lines I think and hope it's the problem...

I think the harmonic balancer is an unrelated problem... They have been known to rattle loose due to harmonics from the flywheel, which is why everyone swaps to a dual mass flywheel.

Anyone else shed any light on the surging?