Belt Tensioner Removal: 1995 525i, M52
On a 1995 525i, M52 motor, how do you remove the fan belt tensioner. I am trying to isolate a squeal. At idle, the car sounds like the engine compartment is full of cicadas. It's embarassing at the stop lights.
Here's what I have done so far:
First the easy part. I removed the A/C belt. The squeal remained. Then I removed the fan belt and ran the engine briefly with no belts. The squeal is gone. Both belts are relatively new and in good shape.
With the belts off, I manually turned the water pump, steering pump and alternator pulleys. They all appear to be in good shape. As does the stationary idler pulley on top. But the belt tensioner pulley seemed a little loose, as if the bearings are worn out. So I thought, "Aha! here's the source of the noise. All I need to so is replace the pulley and the cicadas will go back into hibernation." To double-check I swapped in the pulley from the A/C tensioner which is the same part but appears to be in better shape. Ran the engine and the squeal came back. So now I suspect the tensioner itself. This suspision is enhanced by the fact that when I yank down on the belt from below, and thus compressing the tensioner, it makes a creaking sound as it compresses.
So back to my questions: How is the fan belt tensioner attached to the engine? It's hard to see in the narrow space between the radiator and the engine. Do the water pump and the tensioner share a bolt? Will the water pump have to come out? Bentley doesn't mention it and a search of the archives didn't yield any info. Is the tensioner a likely candidate for a squeal that goes away above idle? Anyone replaced their fan belt tensioner recently?
Thanks for any input.
Eric Fraser
