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R2D2

Water Pump Replacement - M54 Engine

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Job Time:

- 2 hours.

Symptoms of faulty water pump

- Rattling noise coming from pump/impeller
- Increased engine temperatures

I would do this job as a matter of course every 80,000 miles or so. You dont want to end up like me, stuck in the middle of nowhere with collapsed pump bearings!

 

What you'll need


- T-50, T-25 Torx bits
- 10mm socket & Ratchet
- Various length Ratchet Extension bars
- Set of cross and flat headed screwdrivers
- Large splash pan

- M6 bolts

- WD40

- Jack and stands (the smaller the better, wooden planks worked well for me)

 

Parts

 

I would recommend either the GSF or Meyle water pumps as they have a metal impeller instead of the crappy plastic one. You may also want to replace your serpentine and V-belts since theyre coming off anyway.

 

- Water Pump - 11517503884 - £23.75

- Serpentine Belt - 11281437450 - (Optional but recommended) - £8.30

- V Belt - 11281706545 (Optional but recommended) - £5.20

- Coolant & Distilled Water (50/50 mix) - £20

 

 

Tips

 

You may want to replace your thermostat at the same time as replacing your waterpump seeing as you will be removing your belts and dropping the coolant from your system anyway, however it wasnt necessary in my case as a previous owner had already changed it.

Expect to drop around 3litres of coolant from your radiator, so make sure your splash pan is a decent size.

 

Procedure

 

Pump Removal

 

Firstly, get the car on axle stands or something that just raises the front of the car off the floor enough so that you can remove the skid tray from underneath the car for accessing the coolant draining plug. You dont want to have the front too high as it will be at too much of an angle for emptying fluids. Wooden scaffolding planks worked well for me.

 

Place your splash pan underneath and loosen the drain plug (blue and located underneath the expansion tank), then remove the expansion tank cap. Coolant should now flow out of the radiator portion of the cooling system:

 

 

coolant_zpsd464c8ce.jpg

 

 

After a minute or so when youre confident that youve removed all the coolant, move the splash pan underneath where the waterpump is attached to the engine block. When you eventually remove it you should in theory have no coolant spilling out, but its better to be safe.

 

Youre now ready to work from the top of the engine.

 

Firstly remove the front air intake units including airbox/MAF. To do this, there are 3 retaining clips at the front of the unit, and two 10mm hex bolts that hold the airbox to the chassis:

 

 

20121204_155058.jpg

 

 

Then unplug the MAF sensor and loosen the jubilee clip that surrounds it, the whole lot can now be removed:

 

 

20121204_155107.jpg

 

 

 

The next job is to remove the radiator fan. For automatic transmission cars you will need a special fan clutch removal tool, but in this case you just need to unplug the sensor plug and junction box on the left hand side and remove the T25 hex screw and the whole unit will lift up and out:

 

 

 

20130522_163107_zps8f93e5aa.jpg

 

 

Youre now faced with the drive belts which will need to be removed. Before you do though its very important that you firstly loosen the four 10mm bolts that hold the waterpump pully in place. If you dont do it now you wont have any way of keeping the pulley still for removing them once the pump is out. Loosen these slightly for now, but dont fully remove them:

 

 

20130522_163653_zps387ac012.jpg

 

 

Now youll need to remove the two belts. Firstly make a note of their pattern so that you can put them back in the correct position:

 

 

e46beltdiagram.png

 

To remove them, take off the 2 dust caps located as shown, and rotate them using your T50 hex tool in the direction indicated above. This will slacken the tension enough for you to remove the belts:

 

 

5c43c613-f881-4ffe-b8f9-493a73fdee41_zps

 

 

Now that you have removed the belts you can fully remove the four 10mm waterpump pulley bolts and the pulley should come off. You may find (as i did) that the pulley is rust welded to the waterpump, so you may need to apply some WD40 to the centre area and let it soak for a while before giving it a good tug. Trust me, it will come off eventually! Try not to get any WD40 on the other tensioners/pulleys.

 

With the tensioner plate off, you can now access and remove the four 10mm nuts that hold the waterpump in place. With these out youll notice that there are 2 other tapped holes on the left and right hand side of the housing. These are meant for the 6mm bolts in your items list which you should screw into place and use for pulling on the waterpumps housing. Try to pull in equal amounts on the left and right hand side so you dont get the pump wedged.

 

 

pump_zpsb8238fc3.jpg

 

 

With the pump out its just a matter of cleaning the area and replacing with the new pump. Everything else is the reverse of removal.

 

Coolant Replacement/Bleeding

 

With everything back in place youll need to refill your system with coolant. Its recommended that you use the BMW stuff but i just used the Halfords (G40 i think) mixed 50/50 with distilled water.

 

Before you do anything, put your key in the ignition and turn to pos2. Now turn your heat setting all the way up, and your blowers all the way down. This will open up the thermostat to allow the coolant to flow in the system.

 

With the drain plug now back in position and the expansion tank cap off, completely remove the bleed screw next to the expansion tank:

 

fsg_zps02af58de.jpg

 

Now with the engine off but key still in pos.2 gradually add your 50/50 mix into the expansion tank until you see coolant coming out of the bleed nipple.

 

As you top up you will see air bubbles leaking from the bleed nipple. The aim is to allow the coolant to settle long enough to allow all this air to escape to prevent an air lock when sealed back up. After 2-3 minutes of topping up coolant and keeping an eye on air coming from the bleed nipple you should see no more bubbles, at which point you should be ok to replace the bleed screw.

 

Top up any extra coolant that you think is necessary to get the level marker in the correct position and allow the engine to run up to temperature. Keep a close eye on your engine temperature dial, and make sure it reaches mid way and stays there. If you see it go over the midway position, switch the engine off immediately and check your levels/redo the bleeding process.

 

If your temperatures remain stable and everything is running smoothly on the belt trains then youre done!

 

Hopefully you find this guide useful. However I take no responsibility for anything going wrong when you follow the above, its just what i did step by step, and it all worked out for me. If you have any questions, dont hesitate to ask.

Edited by R2D2

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Thanks for the excellent write up. This is my job next weekend. Precaution only ;-)

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This is a top write up!

The only thing i'd say is if you're going through all this then I'd use waterless coolant - get everything drained, put the "sponge" fluid in then drain then fill with waterless coolant.

This way you don't need to worry about changing it, they say it lasts the life of the car and also stops corrosion on internal metal components.

http://www.evanscoolants.co.uk/power-cool-180-for-performance-cars.html

10 / 10 for your DIY guide buddy!

:thumbsup:

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You realize that the waterless coolant (which is nothing more than 100% based glycol) has a much lower heat capacity (20-40% or so), so you will loose cooling power, expecially in hot spots in the engine.

I've read in your lsd topic that you plan on installing a supercharger in the future.... You'll need that extra cooling power.

Besides... normal long life coolant costs maybe 2pound/liter max if you shop sensibly, so you'll need a lot of changes to get the costs of the waterless stuff back.

The waterless coolant is far more suitable for oldtimers where corrosion is a problem due to a lot of different (and inferior) materials in the coolant circuit or mobile homes which make only a few trips a year. But it is not necessary for an all aluminium modern car (m54 engine is all aluminium as are the radiators, so there is hardly any electrolytic corrosion). Waste of money with potential heat problems.

Just make sure that you flush your system every 4 years or so. Use some compressed air in the coolant hose and set the heater to max to get all the coolant out.

Edited by GuidoK

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Trouble is that these cars come filled with normal "blue" anti-freeze (the type that needs changing every 2 years otherwise it turns acidic and rots the head gasket etc). If you want to switch to long life anti-freeze, you have to ensure that every last little bit of the standard anti-freeze has been removed. There are problems if the two mix together. So you'd have to drain, flush, fill and run several times to get out all the blue stuff.

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I think multiple flushes is a bit exaggerated. Just use some compressed air to blow out any remains is sufficient imho.

My car came with yellow antifreeze btw, but color is no indication for the type of coolant. Every manufacturer uses it's own colors, there's no standard.

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I think multiple flushes is a bit exaggerated. Just use some compressed air to blow out any remains is sufficient imho.

My car came with yellow antifreeze btw, but color is no indication for the type of coolant. Every manufacturer uses it's own colors, there's no standard.

Yeap bang on, colour is no where to tell between glycerol and ethylene...

Trouble is that these cars come filled with normal "blue" anti-freeze (the type that needs changing every 2 years otherwise it turns acidic and rots the head gasket etc). If you want to switch to long life anti-freeze, you have to ensure that every last little bit of the standard anti-freeze has been removed. There are problems if the two mix together. So you'd have to drain, flush, fill and run several times to get out all the blue stuff.

Short or long life does not make a difference if they are both ethylene based, its when you mix glycerol and ethylene it will go like jelly, not good...

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Another good write up from the dog there. Some handy hints on the refilling of the cooling system on here too, and I will be needing them soon, as the other day I was under my car changing the engine oil and noticed the bottom of the radiator is bowed like foook!!

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Another good write up from the dog there. Some handy hints on the refilling of the cooling system on here too, and I will be needing them soon, as the other day I was under my car changing the engine oil and noticed the bottom of the radiator is bowed like foook!!

Thanks. Yeah I'd get that done ASAP, the last thing you want is for your car to drop all it's coolant on a long journey!

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^^^^^^^^^^

Absolutely fella!

Id replace the expansion tank while youre there as well.

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Just thought I'd resurrect this guide as it's what I'll be following shortly and seems to be the best one I've found!

Why is it not a sticky anyway?! :D

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thank you and the OP for the info, do you happen to know the torque value for the nuts on the motor mounts themselves? thanks

No sorry, I don't know the torque settings (I assume you're talking about the 4 bolts on the water pump plate?). Was a little while ago that I did this fix on my car but I think I just tightened them up hand tight. I dont imagine the torque setting is that critical as long as you're sensible about it.

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On 19/04/2016 at 21:28, Foxsake said:

Brilliant.. Clear concise.. What level experience for this job?

Sent from my iPhone using Tapatalk

 

So long as youve got 2 hands and half a brain, you'll be fine. Things are never as hard as they seem as long as you give yourself plenty of time.

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