I’m a bit mixed up and got some information that conflicts about the idler pulleys - is the smaller one (70mm) supposed to go by the tensioner and the larger one (80mm) by the PAS pump, or the other way around like how I had them in this picture? I keep going back and forth… Would it be a problem if they’re switched? This is a Bosch engine. Thank you

At 6:05 in this video, he says the opposite, so I switched mine in case they were switched before. Maybe his were, though…





A post here showed the opposite info, which is how I had them in the picture, but I switched them because of the video. My notes showed this is how they were since I had the smaller one labeled that it went by the tensioner…




This diagram seems to show that the smaller of the two idlers goes by the tensioner as I had it originally until I switched it because of that video. I guess his were already mixed up? I guess I’ll switch mine back…

 

The larger one should probably go by the PS pump to allow more belt wrap around the pump pulley and ACE (if equipped) or water pump (if no ACE), but in reality as long as they don't interfere with anything it won't make any difference.

 

I've never noticed a difference or any issue in cars that have the idlers swapped. I have seen 2 small plastic ones, 2 large metal ones, one plastic one worn almost down to the bearing. I would just go with 2 large metal ones to give you the most wrap and the most wear resistance.

 

Thanks, I had them correct which is when I took the picture above, but switched them incorrectly after I remembered something from a video that’s incorrect. I’d use two larger ones, but the kit from AB comes with one 70mm and one 80mm, so I think I need to switch them back how they were.