Serpentine belt diagrams and replacement?

depends if your motor has the auxiliary tensioning roller or not. diagram for with and without are below for the alternator drive belt. for the A/C compressor belt, this will depend if it has hydraulic or the mechanical tension jack. i have posted both choices for this as well.. ALTERNATOR DRIVE BELT (2 possible routes) Without Auxiliary Tensioning Roller

With Auxiliary Tensioning Roller

A/C COMPRESSOR DRIVE BELT (2 possible routes) With Hydraulic Tension Jack

With Mechanical Tension Jack

When I start the car in the morning it sounds like a belt or fan noise under the hood (not very loud) and it seems to go away or get less noisey when the car gets warm... Could this be the fan belt or timing belt?

Also my airbag light stays on and wont go off.

Thanks.

The noise problem is almost certainly the deflection pulley and/or the tensioner pulley/assembly. I like the non hydraulic tensioners, they are cheaper and work just fine. The seat belt issue will likely require scanning to reveal the specific fault, if the fault is the passenger seat belt tensioner, rewiring may be required and not replacement as the fault is in the underseat connector

Engine Mechanical problem
2002 BMW 325 6 cyl Two Wheel Drive Automatic

How do you release tension on the idler wheel to get the belt over it. It has a hyd. cylinder.Is there a special tool?

There is a plastic cap on the pulley that you can pop off and expose the bolt holding the pulley on, turn it and you will then be able to install your belt.

I need alternator belt routing for 2002 bmw 325ci. I have looked for a diagram everywhere under the hood, owners manual with no luck. Please advise,
GJR

Check out the diagrams (Below) for the serpentine belt routing. Please let us know if you need anything else to get the problem fixed.

I had installed a new alternator and put the belt back into place. Now there is slack in the belt. Did I loop it wrong? It is the XI model.

Hello, I am Danny.

Here is the diagram you are I believe you are looking for. I have attached a picture. Hope this helps and let me know if this works for you. Feel free to ask any other questions and thanks for using 2CarPros.
Danny-

https://www.2carpros.com/articles/replace-serpentine-belt

Yes, it worked however, I stripped out the bolt hole holding the hydraulic tension-er in place. Do you think it will be okay or if there is a method to fix the grooves in the bolt hole?

Bummer, you will need to install a Helicoil to fix the stripped bolt hole. Here is the kit you need make sure you get the correct size. Should be 8mm 1.25 thread.

https://www.amazon.com/gp/product/B018LMAXFU/ref=as_li_qf_asin_il_tl?ie=UTF8&tag=2carprcom-20&creative=9325&linkCode=as2&creativeASIN=B018LMAXFU&linkId=816cc6f8bfaf345a947ef3eb6637f702

Let us know what happens and please upload pictures or videos of the problem.

Cheers, Ken

how i replace belt & what is the corect belt # thanks

For the correct size, go to Realoem.com and look for your model, as to the installation, the tensioner pulley cap pops off and there is a bolt head under it, turn to the right to load the tensioner and allow the belt to be installed. For belt routing, see popular site links at the left of the page you are now looking at.

I have a 2001 325 i with 109,000 miles. Two problems, I can hear a light knocking noise coming from the from of the motor between the fan and fan belt pulley. I have had all factory maintenance performed by BMW. Could this be a timing chain issue ?

The insulated panel on the hood developed wear and the foam portion above the intake filter box in breaking apart. My engine is running at the proper temperature.

It would be practically impossible to say what the noise is from where I am sitting. You may or may not have identified an internal engine noise. When did this start and is there anything that makes it change, like time of day, or temperature or speed? The under hood insulation can and does degrade due to time and temp. I would not be terribly concerned. please repost if further information is forthcoming.

1992 BMW 325ic the ac & gen. belt squeals & smokes when the car runs for awhile and continues till I shut car off. The generator does not turn as it should with belt tight. When I loosen gen. the fins turn freely by hand. The ac compressor sounds noisy when running with belt tight.With the belt loose it does not make noise or smoke, but neither are being tured by the belt. With loose belt dash lights up. With tight belt with squeals and smoke dash lights up. AC compressor or Generator?

[quote:8705794015="johnl3165"]1992 BMW 325ic the ac & gen. belt squeals & smokes when the car runs for awhile and continues till I shut car off. The generator does not turn as it should with belt tight. When I loosen gen. the fins turn freely by hand. The ac compressor sounds noisy when running with belt tight.With the belt loose it does not make noise or smoke, but neither are being tured by the belt. With loose belt dash lights up. With tight belt with squeals and smoke dash lights up. AC compressor or Generator?[/quote:8705794015]

Try running the engine with the air conditioning turned off. If the clutch disengages the compressor, then the belt should turn freely.
Fix the air conditioning problem and the belt should be fine.
If the belt has become damaged by slipping, then replace that also.