Low oil pressure
I have an 1997 740 il E38 with under 100000 miles. When I start the car there is a noisy rattle in the timing chain area/lower front. After a couple of seconds it goes away and the engine is silent. I leave it idling until it reaches normal operating temp. About 5 minutes after the engine starts to make rattling noises again. At this time I shut it off.
I put an oil pressure gauge on it and when it start the pressure reads 40 to 50 lbs when the engine is cold. Most times when it reached operating temp the oil pressure remains between 25 to 37 lbs. After about 5 minutes idling at operating temp the pressure goes down to about 21 lbs and it begins to rattle and knock again.
I changed the oil and it stills does the same..
Any ideas? what may be the problem?
Will be thankful for any helpful thoughts or solutions.
This was posted elsewhere and it was recommended to post on this forum.
Appreciate the guidance.