lifters or injectors

[fishingaz]

hi hope someone can help.have a vx 3.8v6. with dual fuel with 230ks.been a great car for the last 5 years but has now developed a loud lifter type of noise.now this happens when half way up any large steep hill or under load towing trailer.when we get over the hill and back off noise goes.towing trailer on the flats noise comes on at 105 ks then back off to 80 and it goes.im running shell oil for lpg cars15w40.
could i be looking at the wrong thing in a lifter problem ?or could it be an injector?
it sounds very metal to metal to me.
any tips at all would be appreciated greatly .thanks.gary.

[GenReaper]

Injectors you would not hear over road noise at that speed.
Sounds mechanical to me, could be lifter or valve or posible broken valve spring or even worn valve guides.
As LPG has no lubrication propperties and im guessing the car has no form of oil injection for lubrication ?

[soop]

Recessed valves or no oil in the sump :P.

[delcowizzid]

or its pinging its tits off from blocked injectors

[soop]

or its pinging its tits off from blocked injectors

Surely it'd given up fairly quickly if the detonation was that bad!

[delcowizzid]

nah can ping for ages will just dent the pistons like theyve been hammered LOL

[soop]

They must be pretty good slugs then. Because that would be a fair punishment.

[fishingaz]

Injectors you would not hear over road noise at that speed.
Sounds mechanical to me, could be lifter or valve or posible broken valve spring or even worn valve guides.
As LPG has no lubrication propperties and im guessing the car has no form of oil injection for lubrication ?

i thought it maybe the gas .but it still does it on petrol as well.