Hi, there,

just changed guides and timing tensioner (1991 420SEL) on right hand side (all MB parts).
I did not fill tensioner with oil, and turned the crank by hand. I felt that every little bit the tensioner would release pressure and chain would slack, then I turn again and it becomes tight again.

I would like to know if this is a usual behavior from a tensioner. I recall my old one did something like that where every other turn it would give slack and the re-tighten.

I am thinking because there is not enough oil pressure, the tensioner is loosening up and then re-tightening.

Anyways I removed the new tensioner, filled it with oil, it is better, the behavior is still there but the slack is better. and once it gets tight, it is really tight.
Ok then I checked the car again, the tensioner has some slack after not turning the crank manually for 2 hours, as soon as I moved the ratchet to turn the crank, it put more pressure on the chain and it became tight. Is this normal?

If the tensioner has a one way valve, does it relase oil and pressure (in the pin on top)? and when?

Thanks everyone