I'm crossing this to Honda and Toyota because there are some sharp
individuals in these groups, and also in the Ford group since this is a
common engine among Fords, IIRC.
The problem: 1989 Mazda 626. Over the course of the winter, occasionally
on cold days the engine would clack from just under the valve cover. Since
I seem to recall seeing somewhere that this engine has hydraulic lifters
of some sort, it just seemed that allowing the engine to warm and
circulate oil would cause this to stop as the lifters (or whatever!)
responded to the rise in oil pressure. It always worked, and when it
didn't, I would check the oil, add 2/3 3/4 of a quart, and be done with it.
Saturday the oil was down less than 1/4 from the Full on the dipstick.
Since it's getting an oil change in about 500 miles, I let it go.
This morning I had to make a trip about 30-35 miles one way. When I
returned home I noticed the engine was making a louder noise than usual,
and when I went to investigate it was the clacking noise from under the
Valver Cover. I shut the car off and let it cool.
Before I left the house later, I added 2/3 of a quart of Castrol Synthetic
(the closest bottle of oil I had) and started it. I let it run for a
while but the clacking continued. I added about 1/3 quart of Marvel
Mystery and let it run till warm and the noise never went away. After
parking the car for about 2.5 hours, when I started it up the clacking was
still there. I drove home still clacking, but quieter.
The partiulars: this is the 2.0L 12-vavle engine, OHC, new timing belt
<3,000 miles ago, fuel injected. It's going to get parked in 1-3 weeks
when I take my Supra out of winter storage. Any ideas about what it is or
what I should look for? If I find the Haynes I will be able to answer more
questions concerning the motor. It looks good and runs great, even with