I cant get them to seal?? just the back bottom corners. both sides. how much torque do they get? I know it cant be much more than 7lbs. is this a common problem on buick 350s? gary
I, too, had the same problem. Using cork gaskets, it appeared were they were not thick enough to seal properly. My solution was to purchase rubber gaskets from rockauto. They are a little thicker and costlier than the cork units but they seal very nicely. No more leaks.
Make sure the oil drain passages in the back of the heads are not plugged with sludge. If oil is not allowed to drain back to the oil pan and just pools on the back of the head, no gasket will stop oil from leaking. This could also be the culprit for blue smoke on cold start up. Oil is pooling around the rear most valve seal and leaking down the valve stem and allowing oil in the cylinder.
First thing I do when I replace valve cover gaskets is to make sure the rails are flat. I have yet to see a set of valve covers that dont need a little TLC with a hammer and dolly. Over the years, the valve cover bolts have been overtightened causing the area around the bolt hole to distort. Ive seen evidence of people using screwdrivers to pry them off too which bends the rails. What you need to do is take a small flat hammer (I use a tack hammer) ,a thick piece of flat stock and tap the rails flat. You can sometines use the flat side of your bench vise. Use a straight edge and go around both covers. You'll also notice that the speaders that are attached to the valve cover bolts are bent as well. Bent those flat again using your vise and hammer. Next take some solvent like DX330 and clean all the gasket sufaces. Make sure there are no remnants of old gasket anywhere. Nothing will stick to an oily surface! Next, take your valve cover gasket and give it a coating of Permatex RTV ultra black (the blue RTV looks like crap). Install the gasket into the valve cover with the coated side to the cover. After you put the gasket in place, coat the head side of the gasket. We're talking about a thin coating, dont glop it on. I run a small bead with the white applicator, then use my finger and go around the whole gasket. Install the valve cover on the engine and snug the bolts evenly. The factory spec is only 7 ft/lbs! Thats not alot of torque. Use a 1/4" drive ratchet and choke up on it to prevent you from overtightening. If you follow these basic steps, you should be able to install valve cover gaskets once with no leaks
Leaks fixed. I bought some valve cover hold down tabs from summit. Nice and dry now and dont look too bad either. I did straighten the original tabs like you said and it did help but it was stubborn in that corner. I did not do the hammer and dolly on the covers themselves. I may go back and do that later and follow your protocol when i hvae my engine running right.
