[Andretti]

Hello, I am new to the forum and up and until recently a proud new owner of a 98 540i. Since march i have gone through two water pumps and a series of belts and hoses. Most recently I replaced everything, again,
and now I cant get my belt to tension. new belt. new water pump pulley. Bad tensioner.? Suggestions.? thanks in advance

 

[Fudman]

You said you replaced everything. Did you replace the tensioner? The cooling system overhaul requires you replace everything, to include all tensioners, pulleys, belts, wp, exp tank, radiator, fan clutch, fan blade, etc. If you can't get belt tension, replace the tensioner.

 

[Andretti]

thanks for the quick reply. Ive already purchased one. my biggest issue is getting the old one off and putting the new one on. the bolt is very difficult to get to. the 13mm socket i have fits fine but due to space there is not really any room to maneuver. any suggestions in this regard.?

 

[Fudman]

sorry, can't help on the V8. The I6 is straightforward. Do an advanced search for V8 cooling system overhaul for more assistance.

 

[Rstyman]

If it is the ac tensioner then I have just finished pulling mine off and putting it back on changing the alternator. If you remove the plastic cover under the engine compartment it is WAY easier to get to from underneath. On my 2002 540i that is how I got it off.

 

[Brandon540/6M]

also just take the plunge and buy a 32mm wrench and take the fan off.. reverse threaded and bang the wrench with a hammer a few times like an impact wrench, and that fan will come off in 39 seconds.. much easier then trying to work around it..

13 mm socket and a funky big ass torx (forgot the size sorry) and you are good

 

[edjack]

Make sure the belts are properly seated on the pulleys.

 

[Andretti]

also just take the plunge and buy a 32mm wrench and take the fan off.. reverse threaded and bang the wrench with a hammer a few times like an impact wrench, and that fan will come off in 39 seconds.. much easier then trying to work around it..

13 mm socket and a funky big ass torx (forgot the size sorry) and you are good

That is quite a plunge for a (hopefully) one time use.. I'll check autozone and see if they have one they can loan. I have the torx it was a t-47 but I can't get it seated to try and get it aloose. I'm afraid to strip it, the stealership is unforgiving. I'll also try accessing it from under the car.
Thanks for your suggestions I'll let you all know how it goes

 

[collardgreens]

Just had to replace my ac tensioner as mine had a cut in it spewing hydraulic fluid as I tightened it.

Not sure if you have hydraulic or mechanical tensioners on yours.
Mine is an 01'.

Wich tensioner are you referring to?
The main belt tensioner or the ac tensioner?

I don't remember using torx for the tensioners
If your not changing the the pulleys.

 

[collardgreens]

The tensioner on the alternator side you have too turn the large nut counter clockwise to tighten the tensioner

 

[Andretti]

The tensioner on the alternator side you have too turn the large nut counter clockwise to tighten the tensioner

mine as welded as some of the other forum members' are. weird im not sure if thats factory or not, but regardless im stuck with just a single "axis" and the two bolts.

I bought the torx planning on removing the entire assembly, allowing better access to the bottom bolt of the tensioner, no success there. As far as the tensioner I believe it is hydraulic. the one on the car now does look worn, specifically the rubber parts.

 

[bluebee]

As far as the tensioner I believe it is hydraulic. the one on the car now does look worn, specifically the rubber parts.

Before you buy tensioners, read this:
- How to tell if you have spring-drive or hydraulic belt tensioners or both (1)

 

[Andretti]

Before you buy tensioners, read this:
- How to tell if you have spring-drive or hydraulic belt tensioners or both (1)

I figured out i have hydraulic one prior to, also ive done very extensive research on this forum, others like it, google and various local certified bmw repair shops. many of the diy posts here in fact encouraged me to tackle the job myself. this forum post was another step in the process, ive never heard of too much advice. thanks for your input.