I am wondering if anyone around there has any ideas about an oil pressure problem I have been having. I rebuilt a 350 chevy engine in about 1998 and it ran flawlessly for years. Then I had several problems very close together. It became very difficult to crank when it was hot. It reached a point where if I turned the engine off, it would have to sit for 30 minutes or more before it would even turn over. During this time, I replaced a bent a pushrod, and a couple months later, a seized lifter. At this point, I noticed that my idle oil pressure was low, so I decided it was time for a rebuild. I pulled the engine out and went completely through it. I replaced everything that I new of that could cause an oil leak: new rings, new bearings, a new oil pump, a new (longer duration) cam, and lifters. The pump is a Summit piece that included a welded on pickup and new pump shaft. The cam is a CompCams XE274H with matching lifters. I also checked all of the oil galley plugs and they looked fine. However, after getting the engine back in the truck, I still had the same problem with oil pressure. The engine produces great oil pressure cold (over 50 psi at idle) but only about 7 psi idling hot at about 700-800 rpm. I took the valve covers back off to check the preload on the lifters and found that oil was spraying out of the rocker arm on #1 cylinder (a steady stream against the fender well). It drenched the side of my truck before I could shut the engine down. Does this mean that another lifter has seized or is it just a result of the low oil pressure? Considering my relatively good oil pressure when cold, would a high volume oil pump help the problem? Do you have any ideas about the root source of the problem?
03-02-2003 08:03 PM
its common for one or two rockers to decorate the fender and walls on a small block, thats why they make "rocker stoppers", have you tried a different gauge? or maybe the line is partially plugged? Did you put in new cam bearings on the rebuild? what kind of main bearing clearance?
Did you check or replace your cam bearings when you did the rebuild?
03-03-2003 07:20 AM
This is not the normal amount of oil that I have seen coming out of the rocker arms in the past. I have always seen a trickle of oil that gets splashed around the engine bay by the rockers. This was like I put a water hose against the bottom of the pushrod and was "spraying for distance". I lost half a quart of oil in the time it took to shut the engine down.
I did not put a guage on the bearings this time around. All I can say is that there was no visible wear on the crank and everything was on the low end of the tolerance during the last rebuild. I didn't replace the cam bearings but they appeared to be in good shape.