1990 Mazda MPV is leaking oil from top of the engine?

Answer 1

A 1990 Mazda MPV with oil leaking from the top of the engine sounds like it could likely be the valve cover gasket(s) - (4 cyl 2.6L engine has one valve cover gasket; the 3.0L V6 engine has two v/c gaskets). The valve cover gasket is made of rubber, and eventually deteriorates and becomes brittle over time ... at which point oil will begin to leak. It is recommended that the valve cover grommets be changed at the same time as the valve cover gasket(s). Those are also made of rubber and get old and brittle over time. If the oil leak is coming from further down below the level of the valve cover gaskets, it could be a camshaft seal leak. On the MPVs with V6 engine, there is a plastic piece (called a camshaft holder?) with an o-ring that often develops a leak. While you're checking that possibility, another common issue is oil leakage from the distributor shaft o-ring. Finally, if you see oil on top of the valve cover where the oil cap sits, you might also check the seal under the oil cap to be sure it's not worn and leaking from there. Another possibility: After replacing the valve cover gasket twice on my 1996 Mazda MPV V6 3.L, and still finding a leak, I took my van to a local repair shop and they found a crack in the passenger side valve cover. The crack was welded and resurfaced. Finally, I have no more oil leaks onto the exhaust manifold.