Replaced Water Pump

S

stirz

Member
 Nottingham
I noticed a ringing sound from the front end and also the main drive belt was cracked on the inside ( full service history :headbang: ) so thought id take the pump off whilst i was under the car , took approx 4 hrs not a hard job .......so if any of you can hear a tinny ringing noise its proberly ya water pump on its way out.....replaced with a metal fin pump as the bmw is plastic . total cost was £70 ish that was for air con belt , main drive belt , pump . (already had anti freeze) :thumbsup:
 
I had the water pump bearing go in my old e36... god did that make a scary noise as the fan wobbled about smacking everything around it!
Glad you caught yours before it gave you that sort of heart attack! :)
 
Sorry no pictures but could help if anyone wants to have a go at it .....i used this that i found on the net

OK..here is how you really change the water pump on a Z4....(E85, m54 motor, mine is a 2.5) I have done this procedure, and all you will need are one water pump with o-ring, two m6x25mm bolts, a gallon of anti-freeze, simple hand tools, a few blocks of wood, a rolling floor jack, and jack stands. It is a good time to replace the belts, so get both of them. Yes, you do have to move the engine..a little.
1. Jack up the car on one side, place a smaller jackstand under the car where the front stabalizer is bolted to the frame. You just need to get the car up enough to remove the front plastic splashpan. Now remove the splashpan, grip it firmly, and toss it at the nearest BMW engineer to show your gratitude for designing a car that has a sheet metal support with webing placed directly infront of the water pump, thereby making it necessary to move the engine in order to remove the water pump, even though there is enough room infront of the sheet metal support to be able to desing it with a slight 1" dip towards the front of the car thereby providing enough clearance to simply remove the water pump unimpeded. Now, jack up the car a little higher, and remove your small jackstand and place a big jackstand (now that you have the clearance) under the car. place the jack on the other side, and jack it up enough to place another large jackstand under the car at the point where the anti-sway bar (stabilizer) bolts to the frame. Now place a rolling floorjack under the engine and place a block of wood between the jack and the oilpan at the front of the engine. Make sure this block of wood is long enough to support the load across the entire width of the oilpan, in order to srpead the weight of the engine across as much of the oilpan as possible, for obvious reasons. You just need to jack it up to meet the oilpan, don't go any higher yet. The reason you do this now is because the underside of the engine will soon become wet with anti-freeze, making everything slippery.
2. Now remove the belt for the A/C compressor (torx bit needed for tensioner)
3. Remove the top plastic (fanshroud?) cover and loosen but don't remove the bolts on the water pump pulley. Remove the serpentine belt. 16mm socket for the tensioner.
4. Now remove the 10mm bolts on the water pump pulley. Tap the pulley gently to get it off. It is made of plastic, so be careful. Remove the 10mm nuts on the water pump. Now install your m6x25mm bolts into the threaded holes on the water pump. Tighten them, and this will remove the water pump from the engine block. The coolant will spill out, but it won't be a lot. Now remove the upper radiator hose only where it connects to the engine by prying the metal clip. Push it up out of the way against the oil filter housing. You can remove the hose before removing the pump, but I did not because it would otherwise make everything wet that I still have to work on.
5. Now remove the nut at the left engine mount. I think it is a 16mm, might have been 15mm.
6. Jack up the engine slowly, but only go up to the point where the engine mounting bolt is just at the lip of the engine mount, where it almost clears the engine mount, but no further. (I would not want to have to line that thing up upon installation. Besides, it is not necessary to go that far.) You should now be able to pull out the water pump going in the direction of the passenger side.
Ta Da! You've now saved your self a lot of money. Now install the new water pump by lubricating the new o-ring with a little ant-freeze on your hand, and install the water pump. Put the car back together. Pour in some anti-freeze. With the car and the heater running, bleed the air out of the cooling system. (With the bleeder screw located next to the resevior cap.) But keep the old water pump. You will need this during your next trip to Germany, when you get the opportunity to throw it at the head of a BMW z4 engineer. This will make them think! It would be different if these water pumps did not fail prematurely.
Hope this helps!
 
Great guide stirz... Lets hope no one needs to use it!! :wink: :thumbsup:

Love the comment about the metal support but hey ho, at least its not a VW where just all of their old engines needed an engine mount off to change the cambelt. Furthermore the waterpumps commonly broke at 70k run by the same belt, yet it wasnt in the service advisory list!!

Edit: Maybe this needs to go into the How To section!
 
Yes my run around is a passat .......wish you could take certain bits off bmw ,vw ,ect and make a car that was easy to work on and didnt brake down ......some examples passat handbrake after 200,000 miles still one click and it wont move as for the z4 i dont have to say anymore.....passat timing belt relacement ya got to take the back wheels off :D .........bmw rear springs.............what a joke.....and so on
 
Good job, but you took the long way around to get there.

When I replaced my water pump, all I had to do is pull the fan assembly. That will give you enough room to remove the water pump.
Same for removing the VANOs hydraulic unit if you do that repair also.

Just a thought.
 
As we say more than one road to London..... :) i had a look at your method but was unsure. The way i used isnt too hard, i didnt follow everything just used it as a guide ie managed to get the belts off/on without loosening the belt tensioners ! :driving:
 
I'm gonna do the WP on my wife's Z4 before it decide to go by itself and planing on going with the EMP Stewart which has always served me well on the other cars...

You mention to remove the fan assembly: I'm at work but if memory serves me well, isn't that behind the metal frame that blocks the WP? I'm not sure I'm clear on how that would help?

I was thinking to lift the engine up a bit with a hoist, but I was also thinking it's probably best to release both the engine and transmission mounts so you don't stress them... No?
 
I know it's been a while but can you confirm that by left you mean UK drivers side/manifold side of the engine when standing in front of the car facing it? Gpoing to replace mine next week as I've got a really faint wiiirrrrring noise that started today (going to replace the belts and tensioners while I'm there, 68k so about time)

Thanks
 
:thumbsup: much better access on that side! Parts ordered, collecting next week and then I'll spend an afternoon swearing at the car and ripping the skin off my knuckles!
 
BMW recently had to replace my water pump because when they took the old one off to do some other work they forgot to store it in a bath of anti freeze (apparantly your must do this or it goes bad - technicians words not mine).

Anyway, it was all under warranty so I didnt pay for a thing but IIRC the cost was about £300 so you saved a fortune.

Andy
 
Well I got the parts this evening so rather than sitting on my butt watching TV I decided to get on with it, job took me about 2h30 not including setting up the ramps and making a wooden block to increase my jack height, pretty straight forward once you get going. I found it easier to undo both engine mounts but leave the nuts on top of the treads so you can't over raise the engine. The pump comes out but it's f-ing tight, even with the engine up you still need to jiggle it about to get the extra 1mm you need. The old belts were totally shot and the water pump had the slightest bit of play in it but at 68k it's to be expected. :thumbsup:
 
Bit of a necro there!

To answer your question though, you actually need to undo one of the engine mounts and lift the engine to get the pump out due to the structural crossmember placed directly in front of it, you can do this from above and save jacking the car if you have an engine crane or similar, the BMW tool for the job sits on the strut towers for instance.
 
Glad this cropped up. Thinking a bit of preventative maintenance on my car wouldn’t go amiss and since I have no evidence of a replacement WP in the past might give this a go myself. Doesn’t sound too bad.
 
I just have a scissor jack and have to replace the pump somehow :|

Should I find some wooden block and jack the car on the oil pan?
 
bbrys said:
I just have a scissor jack and have to replace the pump somehow :|

Should I find some wooden block and jack the car on the oil pan?
Click to expand...

I had the front wheels up on ramps and used a trolley jack and a large block of wood, I wouldn't be very keen using a scissor jack though. You can get decent hydraulic trolley jacks for about £30.

You have to undo the left side engine mount (UK passenger side, intake side of the engine) and jack it up, I left the nut just biting onto the mount thread and it was just enough space to wriggle the pump out, without any risk of the engine slipping and falling off the mounts.
 
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