[SA] WL Statesmen oil pressure problems

[Adambatch]

Recently I've had oil and drive shaft warning coming up on my dash so I've taken it to the mechanic and he said the ECU needs replacing $1400 later and I still have the oil warning coming up on the dash and a lot of engine noise once it reaches 2.5-3 notches. so I took it to another mechanic and he said the timing chain and the oil pump needs replacing $2000 later I still have the oil warning coming up on my dash and a lot of engine noise once the temperature reach 2.5 -3 notches. So I took it back and he said the sump must have sludge problem and blocking the pick up . so he cleaned the Gore's and I still have the oil warning coming up on the dash and engine noise like there isn't a enough oil in the engine but there is plenty of oil and as I said this occurs once the temperature reaches 2.5-3 .What next????