Is this normal? Chain tensioner oscillation?

bpu699 · 10-14-2019, 04:12 AM

Alright, put my motor back together, redid the cam timing to make sure its perfect, popped in the oil fed tensioners (1988 930). Everything looks great. Spun the motor around 5-10 times, no issues, smooth as silk.

Then I noticed that the tensioner was moving up or down 1-2 mm or so during part of the rotation. Meaning, for 180 degrees of crank rotation it doesnt move at all, then for the other 180 degrees or so it moves up and down, slightly. Now, it was just installed, so there is no oil dampening as the unit was just compressed and installed...

But I would think that if the chain were perfectly even, then the tensioner shouldnt move at all while rotating. Right?

Does this mean that part of the chain is more stretched than another part?

Am I over thinking this? Don't think I stretched the chain in any way installing it (I would think it would take massive force to do this)

If the tensioner had oil in it (meaning very hard to compress) then this wouldn't be visible...

Thoughts?

Never saw this posted before, maybe a total non issue...

Catorce · 10-14-2019, 06:56 AM

On the carrera oil tensioners many people will pre fill them with oil prior to install.

dannobee · 10-14-2019, 07:02 AM

Non issue. The chain will load and unload as the valve springs act against the cam.

bpu699 · 10-14-2019, 11:13 AM

Quote:

Originally Posted by Catorce

On the carrera oil tensioners many people will pre fill them with oil prior to install.

Tensioners are old, already prefilled. Had to compress with a vice to get some oil out to put the pin in...

bpu699 · 10-14-2019, 11:15 AM

Quote:

Originally Posted by dannobee

Non issue. The chain will load and unload as the valve springs act against the cam.

Gotcha... that seems to make sense... odd that it only seems to occur during part of the crank rotation, I would think that given that there is pretty much always a vlave getting depressed somewhere it would occur throughout the cycle of rotation...

I think as I am getting closer to "finishing" this motor I am getting paranoid... I really don't want to do this again anytime soon. Though, doing it the 2nd time would be 20x faster...

stownsen914 · 10-14-2019, 03:17 PM

I’d guess the tensioners will compress/oscillate a lot less once the engine is running and they have oil pressure.