How to remove serpentine belt tensioner assembly?

[Roy_Josef]

Hi fellas. Previous owner buggered up the bolt head that holds the serp belt tensioner in place. I also suspect the tensioner arm itself is seized as I can't get it to budge turning it clockwise as you are supposed to. The bolt is actually longer than the space between the tensioner arm and the engine case leading me to believe the whole assembly has to come out to change the bolt. Can anyone comment on this?

[JFP in PA]

The belt tensioner is a nut on the end of a bolt that passes thru the spring arm. There is a great diagram of this on page 13-2 in the Bentley manual. You need to get a wrench behind the tensioner pulley and either screw the bolt back into the spring arm, or remove the tensioner pulley itself and then screw the bolt back in, after which the tensioner arm will rotate counter clockwise.

[Roy_Josef]

Thanks for the reply but I'm not sure you're picking up what I'm putting down. I need to get the bolt out from behind the lever arm. I've already got the pulley off but the bolt is longer than the space between the lever arm and the engine case leading me to believe the whole lever arm assembly has to be removed to change out the bolt. Clear as mud?

[JFP in PA]

Totally, but you are not paying attention either. The bolt that passes thru the “spring arm” of the tensioner (red arrow) can only be removed after the combination belt tensioner housing/hydraulic pump mount has been removed from the top of the engine (read a lot of work, and direct from the OEM 13 volume service manual set). The bolt you are having trouble with needs to be screwed all the way back into the spring arm (towards the pulley) before the arm can swing freely and the belt removed. I am suggesting that you try to screw the bolt back into the position it is supposed to be in rather than try to remove it, which cannot be done with out getting at the back of the housing it passes thru to remove the “tensioning element” (Porsche for the tensioning spring assembly) and then pulling the spring arm forward. But to get to that point, the power steering pump (green arrow) and AC compressor (yellow arrow) has to come out of the way, the housing unbolted and the tensioning spring assembly removed……………….



In this straight on shot of a 996 motor (same layout as yours), you can just see the tensioner arm (coming off #7) going back into the big aluminum bracket that holds the powersteering pump (#1). The AC compressor (area #5) is already off in this shot.



And this is what the arm looks like out of the assembly:



Try and get the bolt back in, you will save yourself a lot of grief if you can......

[Roy_Josef]

Thanks for all that. I suspected the whole assembly had to come out to replace that bolt. Can it be done with the engine in situ? My biggest concern is the 'head' of that bolt has been totally chewed and I needed vice grips on it to hold it while I spun out the 24mm pulley itself. I am hesitant to reuse that bolt as I will need vice grips on it again to re-install the new pulley. Not to mention my suspicions that the lever arm itself is seized in place...

[JFP in PA]

The tensioner assembly can be removed with the engine in the car; there is just a lot of stuff in the way. And, I finally found a diagram for you:



#10 has to come off before the arm, #8, can be released and removed to get at the problem bolt, #6. But as #10 is on the back of the housing, all the other aforementioned stuff has to come off first.

[JFP in PA]

I'm afraid you may be out of luck unless someone has posted a DIY somewhere; the OEM manual is the only source I know of, and even that is not all that great..........