Can I replace the water pump without touching the timing belt?

[eek142]

Car has been running warm recently and I've decided to just replace most of the cooling system since the parts have been sitting around now for a while anyway.

The timing belt was replaced a few thousand miles ago by the previous owner, so it's still good. I've researched and asked around, and I'm seeing differing opinions on whether or not I can install the pump without undoing the timing belt.

The car is a 1989 325i. Will the tensioner spring pose a problem? Can this job be done without releasing tension from the timing belt so I don't have to buy a new one?

[bmw325csi]

yes you can

Its quite simple, take the radiator out for ease.

[eek142]

Will I need a new accessory belt to run it? I read the old one is a pain to get out, so I was thinking of just snipping it.

[jlevie]

The pump only can be replaced but the timing belt tensioner will cause grief. it bears against the pump and you have to fight the spring to get the pump back in. It is almost impossible to accomplish that single-handed and just barely possible with two people. Since there isn't anything other than the bolts to index the pump, damage to the gasket when wrestling it into pump is very possible.

I've done just the pump, once. As cheap as a belt is I won't do it again except in an extreme emergency.

[tinkerputzer]

The water pump can easily be changed separate of the timing belt. Just don't loosen the bolts for the t-belt tensioner.

The trickiest part about changing the water pump is dealing with the tensioner spring. A trick for this, before installation of the water pump, is take the pin and spring and push it as for though the hole in the tensioner as possible then lock onto the exposed portion of the pin with a small vise-grip. When the water pump is bolted in place, just release the vise-grip so the tensioner spring and pin sit in the detent of the water pump.

As for the accessory belt, I believe, you'll have to take off the other belts in order to replace the alt/wp belt.

[bmw325csi]

Thats why you remove the radiator and do it from the front, takes twenty minutes to remove but it saves you tons of grief

[nando]

you don't need the spring if the tensioner is bolted down. it's only there to set the tension while you tighten everything. leave it out when you bolt up your waterpump.

[nando]

and actually, why are you changing just one. they have the same service interval, and the parts are only like $30. just do both.

[eek142]

Thanks for the advice everyone.

and actually, why are you changing just one. they have the same service interval, and the parts are only like $30. just do both.

Well, the previous owner never changed out the water pump from what I understand, but he did swap the timing belt a few thousand miles ago. The cooling system seems to be pretty old anyway, so I thought I'd take care of it now - especially with the car acting funny.

[nando]

ah, that makes sense I guess.

make sure the tensioner bolts are tight, and go for it..

[MR 325]

I has no spring in mine. :)

[Sirotto]

Change the belt. You are talking a 35 dollar part and at least 4 hours of labor. Unless teh prior owner can show you when he bought the new belt and tensioner and has pictures of him putting it in I would change it. But yes can change the pump without changing belt, but why would you?

[Wishno87]

Change the belt. You are talking a 35 dollar part and at least 4 hours of labor. Unless teh prior owner can show you when he bought the new belt and tensioner and has pictures of him putting it in I would change it. But yes can change the pump without changing belt, but why would you?

+1 just do it. Im doing a water pump too right now and im changing my belt and tensioner even though they only have 25K on them because they are RIGHT THERE!!

[ZM Blue Devil]

+1 for doing it all.