Hi Jacques:
Have you checked the filter? It's possible you're using the wrong kind of
filter and it's not holding the oil back inside it after the engine is shut
off. This could result in a lack of pressure on start up. I've seen this
problem on Brit cars with inverted filters. It's unlikely that there is a
failure in the engine. If that were the case, the oil pressure would
likely drop as it warmed up or be non-existant all the time.
John
>I would very much appreciate if someone could give me some clues towards the
>resulution of my problem.
>THE CAR: 1974 MGB. The engine was totally rebuilt about 6000 mi.ago (3
>years).All internal parts were replaced with new parts and assembly was done
>according to the book. Engine was balanced, all clearances were set to specs
>and assembly was done by an old British Layland pro. (unfortunately, he died a
>few months later). The car is not a daily driver but is only used under ideal
>conditions in the summer time, has never seen any "brutal" driving and the car
>is a 98 points. Total mileage on the car is 36,000 mi.since new.
>THE PROBLEM: When the engine is started from cold after being stopped for
>several hours, the oil pressure takes up to 10 to 15 seconds to buil-up to
>normal. During that time taht looks eternity to me, I can hear some knocking
>and chatter coming from some oil starved parts inside the engine. Once
>pressure is up, everything returns to normal with oil pressure between 55 and
>60 psi, whatever the temperature is. The engine runs perfectly with no signs
>of distress. I know I am preparing myself for a pretty hefty bill but I don"t
>know what to look for anymore.
>To try and identify and correct this problem, the following has been done:
>New oil pump installed (gaskets are positionned right)
>Oil lines to the oil cooler replaced and oil cooler cleaned. Oil presure
>checked with an outside oil pressure gauge (confirming the problem)
>3 different brands of oil filter tested ( (top loading) . Oil changed from
>the regular 20/50 to 5/50 (syntetic), 15/40,10/30,5/40 and 5/30. (Have you
>ever heard someone changing oil and filter 5 times in a week end?) I"ve done
>it. Used oil has been tested by a lab and no abnormal traces of metal or other
>substances were found. Oil pressure relief valve has been replaced and spring
>tension checked according to specs.
>The engine will be coming out next week-end and I'll have a look at the
>internal.
>WHAT SHOULD I BE LOOKING FOR?
>Thank you for your help.
>Jacques Dupuis
>Magog, Quebec, Canada
>BRG 74B
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