'98 Z3 2.8L M52 serpentine belt replacement

Hi,

The Bentley manual says to remove the bottom shield and then goes on about taking the tension off of the idler pulley to remove the belts. There is no bottom shield and if there was, I don't see how this would give me any more access to the belts. Do you need to remove the fan and shroud to gain access or am I missing something? I have just replaced the belts, water pump, pulleys, hoses, etc. on my 2000 e46, so I am not a virgin here. I just don't see how to get my hands into front of the engine without pulling the fan, this is not a big deal, but I rather not if I don't have to.


Thanks,
Al

It can be done pretty easily from underneath w/o removing anything. You just have to turn the belt sideways to slip past the radiator. I did it on my 98 Z3 2.8. Just make a simple drawing outlining where your current belt goes (under and over which pulley) and then go for it. I didn't have any trouble removing tension on the idler with a heavy ratchet.

You will still have to remove the AC belt to get the serpentine belt out.

I just did the job this weekend and used the tech guides from Pelican Parts. They were very helpful.. Here is the link, just scroll down to the coolant section.

BK85

http://www.pelicanparts.com/bmw/tech.../tech_main.htm

there are two methods to remove tension on the pulleys...one the Pulley casting has a HEX on it that you can put a socket on and then use that to move the tensioner arm.

The other method is to pop the center pastic cap of the pulley and then use a 8mm (IIRC) Allen socket to again force the arm to move.
http://www.pelicanparts.com/BMW/tech...ement/pic9.jpg

Thanks. I have only had the Z3 for about three weeks now, and loving it. I will get it up in the air over the weekend and see what it looks like before ordering both belts from BAVAUTO. I have also used Pelican in the past, but receive ground shipments from BAVAUTO the next day.

As for the method to remove the tension, I will see if I have the hydraulic or spring type tension pulleys which will determine if I use the allen key or the wrench. Perhaps I will order a new hydraulic tensoiner if I have the spring loaded one along with the belts.


Al

A friendly reminder, when you have it up in the air make sure you check the rear subframe. Mine was cracked and I had to Tig weld it back. According to these forums that problem is pretty common.

Thanks. I am aware of this issue as it is similar, but not the same, as the subframe failure on 1999 - 2000 e46 (I have a 2000). The failure rate on the e46 is 2%, but I don't know the number for the Z3. Anyone?


Al

The E46 issues are NOT limited to 1999-2000 models.

I have repaired a 2003 with the subframe mounting point cracks.

I agree, but later years had a failure rate of less than 0.1%.


Al

OK, it has been a couple of months since I asked about changing the serpentine belts on my 98 2.8L (M52), and I finally had a chance to get the car in the air today. The AC belt tensioner (hydraulic) has the 8mm Allen hole, but the main tensioner (mechanical) does not have the 8mm hole nor the 17mm hex boss nut to put a wrench on. Has anyone encountered the same with their car, and if so, how did you remove the tension to get the main belt off?

Originally Posted by ALM168

I agree, but later years had a failure rate of less than 0.1%.


Al

0.1% = 1000 parts per million. Not sure if this should be considered a low failure rate for such systems.

Originally Posted by aba4430

0.1% = 1000 parts per million. Not sure if this should be considered a low failure rate for such systems.

I think the point is that for any one car (i.e., yours) the risk of failure is EXTREMELY LOW.

Not to belabor, but an owner has a 1000 chances in a million to experience the defect. The question is whether this potential defect rate is considered extremely low?

Back to my original topic......

I used an inspection mirror and found a 16mm headed bolt as the pulley shaft instead of the 8mm Allen that the book describes. Belts changed.


-Al