shfletch
I know this has been discussed before and I have read many posts about it but here is my delema. Fresh 360 with 1100 miles on it, had a lifter bleeding dry over night so every morning for about 5 seconds it would tap until it pumps back up. I replaced all 16 lifters and now when I start it oil pressure is normal until hot, then when starting to drive within 1 mile the pressure drops to around 8psi. If I shut it off, wait 5 seconds and restart pressure comes back up but then falls off again within 30 seconds.
Pressure when warm is never over 50 when it used to be around 60 - 65 at 2000 rpm and above. I figured it might be the pressure valve so I took it apart and it did take some hard bangs on a wood block to get the plunger out. I lightly smoothed it with steel wool and cleaned the housing and re-assembled. Now I have no oil pressure at all when started. I am at a loss and any help would be great....
jeepsr4ever
Before you throw in the rag try a better filter like a wix or napa gold. What weight of oil were you running and what was the temp outside?
shfletch
I am using a napa gold filter and straight 30 weight for break-in. The outside temp here in phoenix is 107 today but last week before I replaced the lifters it was 112 and pressure was normal. When pulling plate off is there a special way I need to prime the pump? I ran the motor about 20 seconds before shutting down with the pressure guage at zero. I did not feel comfortable letting it run longer than that.
shfletch
In my frustration, my pea brain forgot to prime the pump after taking the cover off, assuming this is my problem. I will prime it later today and pull the distributor and spin with drill to see what happens. What are you all doing to have the best luck in priming the pump? Anything special or just oiling the gears and shooting some oil through the filter hole?
jeepsr4ever
Just a clockwise motion and hold it for about 20-30 seconds. I would also take the plunger out and reinstall it to see if their is any foreign particles holding it back.
shfletch
Just pulled the spring, and the plunger slid right out. I filled the oil filter and put it on with minimal oil loss. I pulled the distributor and ran the pump with a drill for probably 3 minutes with no pressure. What am I missing? Should I pull the housing and fill the whole thing with oil or white grease?
jeepsr4ever
Hmmm I wonder if its a pressure sending unit.
shfletch
Its a mechanical auto meter guage, I just pulled the cover and packed with white grease and spun it with success, finally pressure.
Now the bad, fired it up, pressure ok until temp reaches 180 then rev it and pressure no higher than 35, let it idle and it drops to 8. I have had it with this motor, its coming out tomorrow and going back to the machine shop for disassembly. Problems: Had bad lifter bleeding off over night, replaced all lifters, 1100 miles and still using 1 quart of oil per 100 miles, sucking oil through pcv even with valley pan and intake pan with copper pad inside between manifold and pan and line going through 2 catch cans. 3 holes with rings not seating due to oil wash on cylinders with major blow-bye, now rear main leaking.
Now the oil pressure, I am tired of screwing with this thing for over 2 months now and getting no where. So far the machine shop has been real good to work with, he has given me the new lifters and all new gaskets so far, we will see how cooperative he is when I bring the motor back to start from scratch.
jeepsr4ever
A clearance issue somewhere...well if its under warrantee bring her back.
shfletch
I agree, but the bizzare thing is all I did was change out the lifters and the pressure went to crap, it does not make any sence with a minor change like that.....
AMX69PHATTY
I guess you made sure and installed the little platic spacer button thingy in the bottom of the Oil Pick Up assembly to prevent the oil pan from getting sucked up againt the Pick-Up ????? It's an easy thing to over look or knock off when installing the pan. Usually put a lttle permatex, silicone or somthin' on it also to help keep it in place.
Alway closely inspect the assembly of parts at the front of the cam and that they all line up properly. The Oil hole in the forward face of the first cam bearing journal lines up with the grove in the back of the Cam Sprocket and the Sproket has to seal tight against the front of the Cam, then the groove in the back face of the cam sprocket has to line up with hole in the cam, but not be too long to go out past the diameter of the cams front bearing journal, then the groove in the Cam Sprocket hole, and then the Fuel Pump Eccentric also has a groove in the hole that must line up with the Cam Sprocket, and then finally the Distributor Gear has a groove in the hole in it that has to line up too, and finally a hole through the face of the Distributor Gear between two teeth, which sprays out oil under pressure to lubricate the Distributor Gear. All these little passages just to lube the Distributo gear, and they all have to line up or it won't get lubed, and all of'em have to seal up tight and not leak, or one can loose oil pressure.
As far as I understand the only thing that creates preesure in the oil system is there is no where for the oil delivered by the pump to "leak out" very fast, so "back pressure" builds up. The fit of the lifters in the bores, the cam journals in the bearings, all that stuff stacked up on the snout of the cam and the oil hole in the distributor gear, and of course all the bearings on the crank, rods and mains. If any where in the system it "leaks" out oil too fast, pressure will drop. Or on the other hand if the volume of oil delivered by the pump decreases while the "leaks" remain the same, once again oil pressure will drop. Or if the little spacer button on the bottom of the Pick-Up Tube is left off and the pump sucks the bottom of the oil pan up against the Pick-Up and restricts oil flow to the pump, it'll drop pressure.
Some guesses. Sounds frustrating. Good Luck.
