Replace Serpentine belt alone, or Tensioner, Upper & Lower Pulley too?

MrSteak · 02-22-2018, 04:44 PM

2008 E92 just hit 90k miles and I'm having my indy replace OFHG & VCG due to a slight leak. Paranoid about possible Serpentine belt damage from the leaks, I'm having them put a new belt on too.

Do I need to replace the Tensioner, Upper and Lower Pulleys also?

Any other preventative suggestions?

Thanks!

TheeGovernor · 02-22-2018, 05:01 PM

Why not have them check the pulleys while the belt is off?

MrSteak · 02-22-2018, 06:00 PM

Quote:

Originally Posted by TheeGovernor

Why not have them check the pulleys while the belt is off?

Makes sense.

Just didn't know if there was a consensus on replacing pulleys WITH the belt or if replacing pulleys is necessary.

PichaDis11 · 02-23-2018, 02:01 AM

Replace as preventative measure and be done with it. Best to do it now than to figure later on the tensioner and pulley are bad

El Cheapo Loco · 02-23-2018, 11:01 AM

FWIW when I replaced my tensioner at 100k as a regular maintenance item, it felt less than half as strong as the new one. But the belt was still in good shape and riding straight on the pulleys.

Efthreeoh · 02-23-2018, 12:01 PM

I did mine at 300,000. It was still in good shape. The bearing had a little play in it, but who knows when it wore in to that level. The tensioner pulley (not the entire spring assembly) is separately available; it's one of the idler pulleys on the Z3 M44 engine.

Boland01 · 03-15-2018, 08:00 AM

I just replaced my tensioner only rather than the idler pulleys at 90K miles. The bearing in the tensioner was bad. When I rotated the idler pulleys they were fine still. If those weren't $50 a pop I probably would have gone ahead and switched those out too.
Overall, when you remove the electric cooling fan it's not a hard job to do. Just be very careful removing the coolant reservoir crossover pipe on top of fan. The plastic part will be very brittle if it's original.

02-22-2018, 04:44 PM	#1
MrSteak Captain 83 Rep 634 Posts Drives: 08' 335i Coupe (6-speed) Join Date: Mar 2007 Location: New York iTrader: (0)	Replace Serpentine belt alone, or Tensioner, Upper & Lower Pulley too? 2008 E92 just hit 90k miles and I'm having my indy replace OFHG & VCG due to a slight leak. Paranoid about possible Serpentine belt damage from the leaks, I'm having them put a new belt on too. Do I need to replace the Tensioner, Upper and Lower Pulleys also? Any other preventative suggestions? Thanks! __________________ ED & PCD = DONE & DONE! 08' AW/Coral 335i coupe 6-speed (Premium Pkg, Sports Pkg, Heated Seats) *European Delivery
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02-22-2018, 05:01 PM	#2
TheeGovernor Life is better with burnouts 97 Rep 611 Posts Drives: BMW Join Date: Dec 2011 Location: Mile High iTrader: (4) Garage List 1996 Toyota Forklift [0.00] 2007 BMW 335i [0.00]	Why not have them check the pulleys while the belt is off?
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02-23-2018, 02:01 AM	#4
PichaDis11 Colonel 295 Rep 2,202 Posts Drives: E90 N52 Join Date: Mar 2013 Location: NY iTrader: (3)	Replace as preventative measure and be done with it. Best to do it now than to figure later on the tensioner and pulley are bad __________________ Retrofits: 322, 609, 6FL, 6NR, 6VC, 2TB.. Upgrades: Bilstein B8 Eibach Spring kit
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02-23-2018, 11:01 AM	#5
El Cheapo Loco douchebaggo 186 Rep 972 Posts Drives: stick Join Date: Oct 2009 Location: CA iTrader: (1)	FWIW when I replaced my tensioner at 100k as a regular maintenance item, it felt less than half as strong as the new one. But the belt was still in good shape and riding straight on the pulleys.
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02-23-2018, 12:01 PM	#6
Efthreeoh General 17303 Rep 18,727 Posts Drives: The E90 + Z4 Coupe & Z3 R'ster Join Date: May 2012 Location: Virginia iTrader: (0)	I did mine at 300,000. It was still in good shape. The bearing had a little play in it, but who knows when it wore in to that level. The tensioner pulley (not the entire spring assembly) is separately available; it's one of the idler pulleys on the Z3 M44 engine.
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03-15-2018, 08:00 AM	#7
Boland01 Lieutenant 149 Rep 460 Posts Drives: 2010 535ix, 2008, 2007 335i Join Date: Sep 2013 Location: Magnolia, TX iTrader: (0)	I just replaced my tensioner only rather than the idler pulleys at 90K miles. The bearing in the tensioner was bad. When I rotated the idler pulleys they were fine still. If those weren't $50 a pop I probably would have gone ahead and switched those out too. Overall, when you remove the electric cooling fan it's not a hard job to do. Just be very careful removing the coolant reservoir crossover pipe on top of fan. The plastic part will be very brittle if it's original.
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