Changing serpentine belt, tensioner and pulley.
- Thread starter stekar
- Start date
Finland
Hi stekar,
There are three differences in our E85s afaik.
First, as E85 has electric power steering and thus it has just a dummy pulley instead of the pump (lower left).
Second, we tend to have an idler pulley (upper middle) that some M54 applications are missing.
Third, M54s on E85 came with a mechanical tensioner which have a tendency to fail: It’s hard to find a correct roller for these and when replacing the complete tensioner (which are also getting harder to find), it might be an opportunity to do the hydraulic conversion: BMW later on released a technical service bulletin to replace the tensioner with a hydraulic one, which has less noise problems and lasts longer.
I did recently full replacement of all pulleys plus hydraulic conversion to get rid of a cold engine squeak. The water test indicated just a worn belt but finally turned out to be a failing tensioner pulley. The original manufacturer for BMW is INA, but some recommend SKF as well.
There are three differences in our E85s afaik.
First, as E85 has electric power steering and thus it has just a dummy pulley instead of the pump (lower left).
Second, we tend to have an idler pulley (upper middle) that some M54 applications are missing.
Third, M54s on E85 came with a mechanical tensioner which have a tendency to fail: It’s hard to find a correct roller for these and when replacing the complete tensioner (which are also getting harder to find), it might be an opportunity to do the hydraulic conversion: BMW later on released a technical service bulletin to replace the tensioner with a hydraulic one, which has less noise problems and lasts longer.
I did recently full replacement of all pulleys plus hydraulic conversion to get rid of a cold engine squeak. The water test indicated just a worn belt but finally turned out to be a failing tensioner pulley. The original manufacturer for BMW is INA, but some recommend SKF as well.
To add, the reference image on realoem is misleading as it doesn’t show the idler pulley (aka auxiliary tensioning roller) and only shows the mechanical tensioner, which at least my dealer couldn’t order anymore. Correct pullleys are depicted here:
https://www.newtis.info/tisv2/a/en...lt-with-tensioning-deflecting-element/2Zdb00B
In case you’d need to replace the tensioner, INA also has a complete hydraulic conversion kit (INA Mechanical to Hydraulic Belt Tensioner Conversion Kit BMW M52 M54 ref. 533009710). Nice thing with is that the rollers for it can be ordered separately, should it fail some day.
https://www.newtis.info/tisv2/a/en...lt-with-tensioning-deflecting-element/2Zdb00B
In case you’d need to replace the tensioner, INA also has a complete hydraulic conversion kit (INA Mechanical to Hydraulic Belt Tensioner Conversion Kit BMW M52 M54 ref. 533009710). Nice thing with is that the rollers for it can be ordered separately, should it fail some day.