I'm trying to chase an oil leak (or leaks) under my intake. The engine is a 1966 421 Tri-power. I've removed the intake and it appears I'm getting some oil p***ing the lifter pan bolts. Is there supposed to be a rubber washer between the bolt/washer and the pan? It also appears I've got a leak at the fitting in the valley pan for the crankcase ventilation. Is it typical for the PCV valve to p*** oil or do I need to replace the valve, the grommet or both??? Thanks in advance for the help.
Replace that leaky grommet and PCV valve. Replace the hose if it's hard. I always put a fiber gasket [taken from parts left over in old carb kits] or slide a rubber o-ring under the heads of those 2 bolts to stop leaks..works for me.
The only factory seal I've ever seen on the two valley pan hold down bolts has been a thin copper washer. I usually seal them up on the outside with grey silicone after I snug the bolts down. A fresh PCV grommet is always a plus, they do seem to harden up and shrink a bit before too long. They're cheap enough to replace every couple of years to help maintain a good seal.
OK, O-rings on the bolts........ done. I'll seal the outside before the intake goes back on. The valley pan isn't leaking so I really don't want to pull it if I don't have to. The grommet feels like it's plastic, not rubber it is so dried out. I wonder if I can get it out without dropping pieces in........ if I do, I guess the pan comes off. Is the grommet available thought Napa or similar or do I need to go to a specialty supplier? Also, when I put the intake back on, do I torque the bolt connecting the intake to the water pump before the head bolts? I'm ***uming so? Any other tricks? This is the first Pontiac I've worked with, and the intake is a little different. Thanks again.
We ran Pontiac's exclusively in our Nascar modifieds from 1962 to 1976 and chased an oil leak (which is a black flag from the starter and your parked on asphalt tracks) until one of the crew members was watching my father ***emble an engine. What he noticed that no one else did was that the head gasket was protruding past the head enough to slice the valley pan gasket. A little trim and the leak was forever gone.
When I removed the valley pan bolts, there were lock washers on them. Should they be there? I'm thinking some lock***e without the lock washers and a o-ring on the bolt. Thanks again.........
Every Pontiac I've had used a flat washer under the bolt. I think they were copper as mentioned above, but it's been too long since I had a valley cover off to be sure. I just checked my 1961 parts catalog, and it shows just a flat washer, no lock washer. I ***ume later engines were the same. edit: You probably should check the surface of the valley cover around the hole where the lock washer was, to make sure it's not deformed from overtightening. Also, make sure there aren't any burrs in the metal; if so, use a file or something to make sure the surface is flat and smooth.
No lockwashers. No Loc***e, the tension from snugging the bolts down against the valley pan itself will keep them from backing out. The Loc***e will have a hard time holding/setting up unless the threads in the block and the bolts are completely free of any oil, but again it isn't at all necessary. I'd think that by the time you got the valley pan bolts tight enough (don't go crazy, the block can crack in this delicate area and the bolts can go in far enough foul the cam bearings) to seal the pan that the O-rings would get torn up, but I suppose it's worked fine for others here.
Ready to start putting it back together. Do I need to use sealant on the intake gaskets also? If so, what is recommenrded? Thanks in advance.
I always use aviation sealer (permatex) around the water ports on intake gaskets. Some guys use other sealers, some guys seal the intake ports, some guys used the printoseal gaskets with no sealer, etc.
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