I have a 93 EB, 4.0L extended Aerostar. It was a one owner with 133,000 miles on it when I bought it. The heads had been replaced at about 90,000 Mi. The valve covers are leaking a small amount of oil and of course it smells bad. This is a fairly expensive job, close to 5 hundred dollars here in CA, as I have to have a shop do it. I have reached an age that really has slowed my ability to do my own repairs. I have replaced the PCV as it was partly plugged, and this helped for a while, I retorqed the cover bolts that I could reach at the same time. I love my star and this is my second one. I wonder if anyone has gone through this before. What are the best gaskets? Are there better aftermarket valve covers avail. or maybe a girdle of some type to spread out the presure? Someday I will probably rebuild the engine, but as of now it does not burn any oil and runs great, so am looking foreward to 200,000 or so before major work. I hope to have this gasket replacement last until the rebuild. Any sugestions would be appreciated! I see so many good answers here.
I have a 93 Ranger with the 4.0L and just recently I had to replace the valve covers due to rust eating a couple of pinholes in the drivers side cover and the passenger side cover was about to do the same. The only place that I could find them was at the dealership for a cool $150.($100 for the right side, $50 for the left side) For valve cover gaskets(about $30 which includes upper and lower intake manifold gaskets), I went with the Fel-Pro Permadry Plus from autozone. No RTV silicone required and they were easy to install. Now 10,000 miles later, no leaks! I also used the same gaskets on my 2.9L I just rebuilt. I've put about 1,000 on it and no leaks.
If your using the same valve covers, make sure the surface that contacts the gasket is straight and flat.