timing belt 89 325i

[Nick325is]

I also had allen head bolts on the rotor when I replaced it.



-Nick

[DJB]

The cam shaft gear is held on by a bolt with one of three heads:
8mm, T50 or E12

I had a 8mm and E12 ready at the time. Guess which one I had? Hint: I still have the cam shaft seal and o-ring ready for the next time.

I suggest taking the distributor cap and rotor off (10mm socket, 3mm hex) before starting the job to see which you have and to verify that the rotor screws can be loosened without destroying them.



The reason for turning the crank twice is make certain that the belt has settled in before bolting down the tensioner. You can turn it more than twice if you wish. The first time you probably will turn engine a bunch of times to be certain you have it right. Once the tensioner pulley is clamped down, the spring has no function until the next timing belt change. This is not clear from the directions.

[viali8]

thanks that clears some stuff up. So what is the purpose of the spring?

[bimmer8604]

Just for setting the tensioner against the belt while installing for correct tension. Also, don't forget to re-torque your front crankshaft bolt. Being your first time it should take 2.5-3 hours, maybe a bit longer. I know the first time I did mine I also replaced my head and all the seals/gaskets and that was about an 8 hour job with a dinner break and other interruptions. It also helps to have a lift:-).

kyle

[viali8]

thanks bimmer8604

[8atman]

I have heard that you should chance your timing belt every 50,000 is that to early or is 70,000 the standard?

Thanks

[viali8]

t-belt

Yes, you should change your timing belt every 50,000 miles

[DJB]

60,000 miles was the original recommendation.

I don't know where it is documented, but many now suggest 50,000 miles or a maximum of 4 years.

You only need to change the tensioner and water pump every other belt change, but you'll often end up changing them just because you don't know the service history.