Questions and Answers

Mazda 626 Hydraulic Lash Adjusters Q. 1995 Mazda 626 2.5 liter DOHC 195,000 miles. I have an upper engine clacking. When the rpm is above 2,000 the noise goes away. Sound is coming from the rear cylinder bank. I replaced all 24 cam followers (lifters). This did not fix the problem. Cam lobes appeared to be in good shape. Cam bearing shows little to no wear.

The clacking is like putting a playing card against bicycle spokes and spinning the tire.Could this be coming from the injector rails? Could a weak oil pump cause valve lash to sound and behave like this?

Allen

A. Low oil pressure would most certainly cause the Hydraulic Lash Adjusters (HLA) to be noisy. What you should do is hook up a mechanical oil pressure tester up and see what the actual oil pressure. Engine Oil Pressure at 3,000 rpm should be about 48 to 71 psi.

Of course if it were low oil pressure, it would effect all the HLAs, not just one bank. You could very well have a blocked or restricted oil feed to that bank. If the inside of the valve cover and top of the cylinder head looked kind of dry, this would tend to confirm that.

Are you serious about your name??!? I think that's very cool. Your parents must have a great sense of humor! I'll never again be able to look in my tool box without thinking of your name.