The oil pressure light coming on at idle is not a big worry, so long as it goes out as soon as revs rise.. First step is to remove the oil pressure sender unit and screw in an oil pressure gauge. a mechanic can do this for you. This will tell you if the sender is faulty (common enough) or the oil pressure is low. A rule of thumb is to have about 10 psi per 1000 RPM in the normal rev range
If it is indeed low, possible causes are - worn big end or main bearings (the car is old enough) -faulty or weak over-pressure relief valve in oil pump -worn or faulty oil pump -blocked or sludged up oil passages -blocked or sludged up oil pickup strainer mesh in sump
Some of these can be investigated by putting the car on a hoist and removing the sump . .
Answers & Comments
The oil pressure light coming on at idle is not a big worry, so long as it goes out as soon as revs rise.. First step is to remove the oil pressure sender unit and screw in an oil pressure gauge. a mechanic can do this for you. This will tell you if the sender is faulty (common enough) or the oil pressure is low. A rule of thumb is to have about 10 psi per 1000 RPM in the normal rev range
If it is indeed low, possible causes are
- worn big end or main bearings (the car is old enough)
-faulty or weak over-pressure relief valve in oil pump
-worn or faulty oil pump
-blocked or sludged up oil passages
-blocked or sludged up oil pickup strainer mesh in sump
Some of these can be investigated by putting the car on a hoist and removing the sump
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