What does the Idle Pulley Tensioner look like (see pics)?
Does anyone know what the pulley itself looks like? I have the extra rattling sound when I turn my AC on and was told the sound is caused by a loose and aged Idle Pulley Tensioner that needs to be changed...
So I've done a google/ebay search and i get a few different images...
I hear you could replace the idle pulley tesioner yourself....it's as simple as replacing the belts...
here are two separate images I get for the search: which one is it...?
Make sure it's the idler pulley though, because whether or not your AC is on, the idler puller is always turning as long as the engine is running, so if we think about it the idler pulley should make a rattling noise whether the AC is on or not. Someone might say because of the load the AC puts on the belt when it is turned on the pulley will make more noise, but AC on or not the tension of the belt on that pulley is basically going to be the same.
The noise can be coming from the compressor as well. Just food for thought.
The top tensioner you posted, which looks like a shock absorber, is the idle pulley tensioner, and the bottom is the water pump belt tensioner. If you are having a problem with the water pump pulley making noises, you may need the second one, but if it is the other belts and pulleys, you would need the idle tensioner. It is an easy fix, but be patient and you may want to have someone to help deflect the belt tensioner, while you remove the belt and then replace the part.
Oh, and I have the parts manual on CD, so if you give me your model and year, I should be able to tell you exactly what part # you need, if you know whether the water pump belt, or something else is causing the problem
DelMarco don't buy used parts off a 328i (M52 6 cylinder) for your 318i (M44 4 Cylinder). Most of the time they're different parts. On your 318i you actually have both those type tensioners you pictured, but which is worn out is the question. How old is your belt? Do you see it jumping near one tensioner but not the other? The A/C tensioner is p/n 11 28 2 245 087 and looks like this:
The water pump / alternator tensioner is p/n 11 28 1 748 131 and looks like this:
The 328's alternator / waterpump tensioner looks like this:
Which is what you showed in the bottom pic.
Call the folks over at Bav Auto and talk to them. They stock all new original parts anyway.
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