mikegreen

The 2004 has the N52, right? So I have the belt driven water pump.

I searched but couldn't find a writeup on the water pump replacement for it.. I have the Bentley manual coming with the parts from ECS... I assume its in there?

KyleB

2004 530i has M54B30. yes, belt driven water pump. when I get home tonight I'll find a couple of good threads for you. If you're even somewhat mechanically inclined, you can definitely do this.

PM me if you need help.

KyleB

Pelican Technical Article: BMW Water Pump Replacement

It's an E36 thread, but the procedure is almost identical for M50/M52/M54.

- you can remove the water pump by threading in bolts into the two open holes on either side of the pump. doing this will 'push' the pump away from the block rather than beating on it with a mallet. pounding on it with a mallet is a recipe for breaking a stud, so I don't recommend it.

-first step to any of this is to remove the fan assembly. two electrical connections at the right (passenger side), folding the left side mount arm to gain access will allow the fan to slight right out. second step is to remove coolant (duh). you might want to buy a new drain plug for the radiator, just in case it snaps (it's probably going to. buy one. it's $9)

-replace any tensioners, pulleys, etc you want to as everything is very accessible with the fan and radiator support covers out of the way.

-if you're replacing the lower radiator hose, do yourself a favor and buy a new coolant temperature sensor. see that green o-ring on the sensor you just removed? it's probably not going to seal anymore. yea, I know it looks OK. It isn't. if you're leaving the lower hose alone, no need for a new sensor.

Finally, if you run into any problems there are more DIY threads on this out there than you can count. Google is your friend

mikegreen

Sweet, thanks for the help Kyle!

-Mike

mikegreen

Done!

Got what I thought was everything from ECS, but somehow deleted the water pump out of my cart when I made the order... So, got a water pump locally for about the same price, dunno who makes it - but lifetime warranty and it felt MUCH happier than the one coming out... the 127k mile pump had some shaft slop (first time to say that).

I spun the pulleys and the tensioner pulley was noisy - I ended up getting the AC, tensioner, and idler (the one bolted to alternator) pulleys locally - one from Orielly, others from Autozone. I'll post the p/ns once I find the receipts.

I've had some yellow gunk in my oil cap lately, from winter driving and short trips I think - and, the heat hasnt been really warm unless I'm idling... So I hope the thermostat was going and it'll be happier now. We'll see.

Overall took about 4hrs, including 1.5hrs driving around and to the autozone 'hub' store to get the hard-to-find tensioner pulley.

thanks for the advice!

-Mike

KyleB

glad it worked out for you. not surprised that everything was worn at that mileage. you were smart to replace things when you did.

balbs

Don't mean to thead jack, but how do you know when you need a new water pump before you get overheating issues? How do you test it? My car just hit 70K miles.

pcy

Pulley driven water pumps typically have a weep hole and the coolant starts to leak from there. Also, when you drop the belt and spin the pulley, you can feel some 'play'. This is what mikegreen is referring to 'shaft slop'. Other than that wait for the pump to fail and get stranded somewhere on the road or go the preventive maintenance route and replace it while the car is in the garage and you have some time.

mikegreen

balbs - what year is your car? If you have the mechanical pump - I'd just replace it. Its $50 and under an hour of work. Also replace the plastic pulley - mine had signs of stress...

regards,
Mike

balbs

Mine is an 06' 525i with N52 engine. Don't know yet if it's mechanical or electrical pump.