Water pump R&R

seatacus · 10:40 AM

I've gotta leak in my 1985 325e. Is water pump R&R a major deal? Does it involve messing with the timing belt? Or is it a simple unbolt and replace. The Haynes manual is very vague.
Thanks in advance
Mike
Renton,WA

Dub-Dub · 06-29-2004, 11:31 AM

I am quite sure it does... I've done teh job before and the water pump is behind the belt if I am picturing it correctly.

Recently my mechanic told me my water pump was going and I should think about replacing it. I replaced it 23K ago... any way it could go that fast, and secondly, how would one diagnos it as needing to be replaced soon... what was he seeing that I am not? (yes I will ask him, I just haven't been by lately)

jase007 · jase007's Garage

Honestly Guys... I have only replaced water pumps when doing the timing belt / tensioner. I would think that Bentley's would give better diagrams and explanation of the procedure (can one do the pump and not the belt) than Haynes. Just my experience. I have Haynes and Chiltons for my '99 Suburban and they are horrible in comparison to Bentley's well documented instruction.

I am pretty sure you need to do the timing belt as well. AND, why not ... belt and tensioner are cheap and are cheap insurance. Depending on mileage ... inspect the camshaft seal as well for leaks (leaks onto TBelt and causes slipping / swelling / breakage).

Jason

Jared at Pelican Parts · 07-01-2004, 06:37 AM

OK< it's pretty easy to do, however it involves the removal of the following...

Hood, makes the job much easier, just pop the hood, leave it down and remove the six 10mm bolts and the hose going to the washer reservoir, lift the hood off..

Radiator and all hoses, some people will debate this, but its easier to do it with it out.

Power steering, A/C and water pump belts.. I'd replace them all while you're there

Fan and clutch. You'll need a 32mm open end wrench and a means to lock the pulley. Pelican sells a tool for this.

water pump and lower crank pulley.

Distributor cap and rotor

upper and lower timing covers

Line up the upper and lower timing marks, then relieve the tension on the timing belt and remove it.

Remove timing belt tensioner.

Unbolt water pump, remove and clean the surface on the block

Installation is the opposite of removal...

The Bentley manual does a much better job of explaining this... Or if you like, you can give me a ring and I'll explain it in detail.. Done it so many times, I can get it done in about an hour..

1-888-280-7799 ex. 259

Dub-Dub · 07-01-2004, 08:12 AM

An hour!!! that is amazing... wow... I think I am at like 4-6!

Jared at Pelican Parts · 07-01-2004, 08:18 AM

Well, that's "Got to get the car running to get to work tommorow" time....

seatacus · 07-06-2004, 04:54 AM

All of you,thanks so much.
Mike

Mark325is · 07-08-2004, 11:09 PM

Here's a quick follow up question to this water pump r&r thread. I'm noticing that Bentley and some other tech how to walk through guides are not mentioning the use of gasket sealers on the water pump, thermostat or belt housing covers. Are they not needed on M20 motors (87 325IS)? If usage is recommended, what are you using?

I’m about to change out the H2O pump, thermo and timing belt this weekend and I’m looking to be prep’d with all the essentials before starting.

jase007 · jase007's Garage

Mark:

Quote:

gasket sealers on the water pump, thermostat housing

Yes, I use Permatex product (get at any auto store). None needed on the M20 TB covers.

Jason

Mark325is · 07-09-2004, 04:00 PM

Perfect! Thanks for the the reply. I've used permatex on other car pump replacements so should be a breeze.

7hills · 07-10-2004, 07:26 AM

Permatex works great for the gaskets, but would you use it for the o-ring on the t-stat housing? I don't use sealers on the o-rings and have yet to have one leak. Not sure about everyone else, just my .02

bderrick · 07-11-2004, 02:14 PM

Just a note on the water pump gasket - I've been also told not to use sealant on the gaskets I was using. They have sealed fine after a water pump replacement.

So far as the timing belt replacement - it is not that hard but you really need someone to guide you. You cannot get the timing marks out- of - line or you will have disaster. The new belt can be pretty difficult to get on, they are very tight. but you can't turn the cam sprocket to get it to fit or you will throw off the timing. The water pump provides support for the tensioner spring so when you pull the pump you have to be careful not to let the tensioner spring pop out. It is best to do both jobs at once. They usually require it at about 50 - 60,000 miles.