This is a weird one one me. I just put my car on the road after 10 years of restoring it. The motor is a rebiult LS5. I have about 75 miles on it so far. When I am idleing with the car warmed up I get 60lbs of oil presure. When Im driving the presure drops down to 40 lbs. I pull up to a light and the presure goes back up to 60lbs. I have enough oil in it. The motor sound good and runs fine. I have always had motors that would drop oil presure at an idle and increase at higher driving rpms this is the first motor that I have had to do this. Any ideas.

According to Melling's web site www.melling.com (http://www.melling.com) (I think that's it) a drop in pressure as rpm rises is usually a rod bearing with too much clearance. As the crank speed increases the oil is thrown off the rod bearing faster than it can be replaced, causing a drop in pressure. Check out their tech section, lots of good info.

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Pat Kelley
66 El Camino, daily driver
67 El Camino, STRIP/street

Don, another possibility may have to do with oil pickup spacing off the floor of the oil pan. I've always shot for 3/8".Sometimes more or LESS can cause a vorteching of oil and start sucking some air. Along those same lines if there is any 'leak' between the pickup on up the tube it may be covered with oil at low rpm then as rpm increases and oil level decreases along with some normal vorteching it may start pulling some air in as that leak becomes uncovered. It just reminds me of oil level problems either statically or dynamically. Best of luck. Rob