Water Pump Leak

[benben]

Coolant kept leaking and upon inspection it seems to be leaking onto the belt, water is coming from the area where the water pump is located. Im assuming there is a seal around the water pump somewhere that is leaking heavily. Would you guys recommend a change of the entire water pump? and is that a big job? looks like a lot of things need to come off for it to happen.

Cheers,

Ben

[srhutch]

If it is the water pump seal then by default you would replace the water pump, as you have to remove it to change the seal. On most cars where the cambelt has to be replaced at regular intervals the water pump is also replaced even though it looks ok. Reason being a new belt could add additional tension around the pump which could then start to leak.

Our cars are chain driven not belt, not sure how the pump is driven tbh.

[jamie_z4]

If it is the water pump seal then by default you would replace the water pump, as you have to remove it to change the seal. On most cars where the cambelt has to be replaced at regular intervals the water pump is also replaced even though it looks ok. Reason being a new belt could add additional tension around the pump which could then start to leak.

Our cars are chain driven not belt, not sure how the pump is driven tbh.

its driven by the accessory belt which drives the alternator.

its not a big job on the M54. The pumps are around 50-70 quid from ECP.

[raymond.harper]

http://www.pelicanparts.com/techarticle ... cement.htm You will need to remove engine splash panel and will also need a torq socket for both drive belts. Not a lot of room at the front of the engine !

[firebobby]

http://www.pelicanparts.com/techarticle ... cement.htm You will need to remove engine splash panel and will also need a torq socket for both drive belts. Not a lot of room at the front of the engine !

That's a good guide

[Chris_D]

WOuld suggest replacing the oil filter housing gasket while you're going to be tinkering around that area as theyre prone to leaking....

[MJJamieson]

And i would do the thermostat too while your on, removing it makes the access to the pump easier. You will also need to undo the engine mount and canter the engine over to be able to get the pump past the the front crossmember.

[MACK]

Although it could be the seal. On this engine its just as likely to be the pump itself. Dont mess around replace the pump, check the condition of the serpentine belt as well as that might need to be renewed (just done mine as the belt was cracked) the cooling system on the M54 engine is known to need some TLC, the expansion tank being another common failure (just done mine)

[maxman]

http://www.pelicanparts.com/techarticle ... cement.htm You will need to remove engine splash panel and will also need a torq socket for both drive belts. Not a lot of room at the front of the engine !

That's a good guide

Agree,some good info on this site.

[benben]

Thanks for all the advice gents.

The lower radiator hose seems to be leaking aswell (very small leak) but im thinking of changing that aswell. Probably a better idea than using glue.

So you reckon change the thermostat aswell?

This is quickly turning into an expensive ordeal.

[MJJamieson]

Thanks for all the advice gents.

The lower radiator hose seems to be leaking aswell (very small leak) but im thinking of changing that aswell. Probably a better idea than using glue.

So you reckon change the thermostat aswell?

This is quickly turning into an expensive ordeal.

The thermostats come with the plastic housing which has a rubber seal that goes brittle and leaks, your going to drain the coolant anyway so it makes sense for less than £60.

[benben]

True.

So ended up getting a new water pump, lower radiator hose and thermostat. A mate of mine is gonna do it for me this weekend. fingers crossed haha. Will be using the above guide:

http://www.pelicanparts.com/techarticle ... cement.htm

[MJJamieson]

That guide is for the S54 engine, yours is a M54, there are some good guides on YouTube for your engine, sometimes it's better looking for M54 engines than for Z4.

[raymond.harper]

Good luck with the job. Take your time and it should be alright. From memory the lower hose may have a sensor which is held in by an O ring which sometimes leaks.

[Marius]

here's a tip for you to avoid struggling with water pump removal , remove passenger sides engine mount nuts and lift engine by 15-20mm , will make life much easier .