The factory
The FACTORY plastic cover is the only way to go. The aftermarket aluminum covers look neet but will leak quicker than the factory plastic one. They don't
have proper baffles which allows oil into the air cleaner and the pcv valve will start to drink mass quantities of oil. they also have a puch in oil cap that sits over the front rockers that has a tendancy to all out after the rubber hardens in a few months. The rear of the cover also has a yery thin section near the rear head bolt where the gasket (special) tends to slip outof place. Did your kit come with the updated headbolts and clamp washers? Did you clean off the surface of the head spotlessly? You could also try re-sealing the cover you have now using a high quality rtv sealer and making sure the head and cover surfaces are 100% oil free and letting it cure overnight. The best solution to this problem is to replace the head with a late YJ 4.2l one that has the factory aluminum cover. All other parts are the same. Its a bolt on for 86 & 87 engines with 1/2" head bolts. The 81-85 used 7/16 head bolts so spacers may be needed to keep the late head centered on the block. I work at a Jeep dealer that used to sell the aftermarket covers but I won't use them any more as I can't guaranty them not to leak for the customers. I hope this helps.
did you
The FACTORY plastic cover is the only way to go. The aftermarket aluminum covers look neet but will leak quicker than the factory plastic one. They don't
have proper baffles which allows oil into the air cleaner and the pcv valve will start to drink mass quantities of oil. they also have a puch in oil cap that sits over the front rockers that has a tendancy to all out after the rubber hardens in a few months. The rear of the cover also has a yery thin section near the rear head bolt where the gasket (special) tends to slip outof place. Did your kit come with the updated headbolts and clamp washers? Did you clean off the surface of the head spotlessly? You could also try re-sealing the cover you have now using a high quality rtv sealer and making sure the head and cover surfaces are 100% oil free and letting it cure overnight. The best solution to this problem is to replace the head with a late YJ 4.2l one that has the factory aluminum cover. All other parts are the same. Its a bolt on for 86 & 87 engines with 1/2" head bolts. The 81-85 used 7/16 head bolts so spacers may be needed to keep the late head centered on the block. I work at a Jeep dealer that used to sell the aftermarket covers but I won't use them any more as I can't guaranty them not to leak for the customers. I hope this helps.
did you
