Wobbly Water Pump Pulley

[Noamit 2]

Hi everyone, first time poster and a mechanic-wannabie here.

TL;DR M54B30, took the belts off and found the water pump pulley to be wobbly.

 

My E39 530i recently developed a pretty serious leak, but I wasn't sure exactly where it was coming from.

The front end of the engine is quite dirty, and since I've never even inspected the belts I thought this'd be a good excuse to take the fan, shroud and belts off so I know how to do it, clean the area, put everything back and see where the leak is coming from.

After taking the belts off, I noticed the water pump pulley has a lot of play.

Is this normal, and if it isn't, what should I do?

Thanks in advance 

[Vass 809]

Replace the water pump, it looks to be well munted. The pulley looks to be solidly attached and it's the whole assembly that's loose. Even with no bolts holding the pump in place it shouldn't have that much play. The water pump is a critical maintenance item so it's well worth throwing on a new one regardless. The pulley itself is reusable but it's plastic and does get brittle over time, they often crack and break when taking off so you might need a new one of them as well.

[Eagle 1659]

Water pump bearing about to fail completely, probably leaking badly. Looks like your cooling system has been running straight water with all that staining everywhere

After replacing the pump get it pressure tested for leaks. If no leaks then re-fill with coolant.

[Noamit 2]

2 hours ago, Vass said:

Replace the water pump, it looks to be well munted. The pulley looks to be solidly attached and it's the whole assembly that's loose. Even with no bolts holding the pump in place it shouldn't have that much play. The water pump is a critical maintenance item so it's well worth throwing on a new one regardless. The pulley itself is reusable but it's plastic and does get brittle over time, they often crack and break when taking off so you might need a new one of them as well.

Thank you!

Time to pour more money into this bottomless pit.

[Noamit 2]

37 minutes ago, Eagle said:

Water pump bearing about to fail completely, probably leaking badly. Looks like your cooling system has been running straight water with all that staining everywhere

After replacing the pump get it pressure tested for leaks. If no leaks then re-fill with coolant.

Right, this might be the culprit for the leak too then.

Judging from the mess I suspected it might be coming from the top of the engine.

Good to know that water causes staining! I realised there's a leak when I was on the road and the engine temp started rising. All I had was water which was enough to get me home.

[Vass 809]

Let me tell you about bottomless pits...

As far as water pumps and coolant changes go, it's a fairly minor hit, especially if you DIY. Fairly quick and easy job and well under $200 in parts and consumables if you're smart about it. Check the date on the thermostat too, it'll probably be 10+ years old and well worth changing with the coolant drained.

Hope you caught it before the temperatures crept too high, these engines are very sensitive to overheating with both the block and head being aluminium.

[Eagle 1659]

Its a bit hard to tell from the video but it looks it on the tensioner pulley or maybe be its baked on oil, only you can determine that.

As above these are easy to cook, may pay to get a leak down test done if you didnt shut it down right away.

[mmario 46]

Having done all of this recently just ensure you bleed the system properly when finished, plenty of guides online.

[Noamit 2]

Update:

I don't think water pumps are supposed to look like this.

[Noamit 2]

Honestly, things are looking pretty gross in here.

What would be the best way to clean this so the new pump can be installed without damaging the o-ring?

[Eagle 1659]

Well neglected, must of run impure water for awhile.. Id probably use a wire brush and\or scotch pad. Lube the oring and bore with vaseline, rubber or silicon grease when installing

[Vass 809]

That's crazy. Hopefully hasn't spread to the rest of the engine that badly. I'd take the radiator hoses off and flush the whole thing through a few times, even with just a garden hose. The radiator too, or just replace. There's a drain plug on the exhaust side of the block, bit of a pain to get to but worth draining the last bits of crap out of the engine if you can be bothered with the hassle. I'd then fill it with just demineralised water, run it up to temp and do another flush (or two if what comes out is still yucky) before filling with coolant. 

[Noamit 2]

So I installed new belts, new pump, cleaned the area as much as I could, then flushed the system twice with distilled water.

I then used a Penrite radiator cleaner before putting antifreeze in, and it started making this noise...

Bad pulley? Turning AC off doesn't stop it. It took about 30 seconds after starting for the sound to begin the first time.

I've stopped and started the engine again, and that time the sound immediately came back

[Noamit 2]

I'll also add there was one day between me doing the two flushes yesterday evening and using a cleaner this evening.

[Vass 809]

Take just the AC belt off and check if the noise is still there. Take the rest of the belts off, spin all the pulleys by hand, check for noise. Must be something really obvious if it's that loud and instant.

Are the belts routed correctly? Does the AC belt have the correct number of splines? There were 2 different types of AC pulleys, harmonic balancers and AC belts depending on production date. That's the first obvious thing I can think of. 

[Eagle 1659]

Check all the components that run off the belt with your ear to a screwdriver, pry par or something long and metal. It will be obvious whats the cause with a sound that loud.   

[e30ftw 410]

The belt will make that noise if you got coolant on it. I did that recently and had the exact same noise. You can either try cleaning off the belt with some electrical cleaner (doesn't leave residue), in my case this helped a little, or suck it up replace the belt again like I ended up doing. I'd just finished replacing the pump, thermostat, belts and tensioners too so that was fun doing the belt again..

[Noamit 2]

17 hours ago, e30ftw said:

The belt will make that noise if you got coolant on it. I did that recently and had the exact same noise. You can either try cleaning off the belt with some electrical cleaner (doesn't leave residue), in my case this helped a little, or suck it up replace the belt again like I ended up doing. I'd just finished replacing the pump, thermostat, belts and tensioners too so that was fun doing the belt again..

This did cross my mind, which is why I bought new belts. I inspected the old belts and the conditions weren't too bad, so I kept them in case I needed it. Glad I did.

The new AC belt was incorrect. To Vass' point, I needed one with an extra spline. I put the old belt back in and the sound is gone.

Pulleys aren't exactly mint so I think I will replace them soon too. The corrosion was quite nasty, so I will be putting fresh coolant in soon, but I think I'm going to disassemble the system again in a few weeks to check the AC and thermostat holes and see if they're clean.

I've had the car for a few months and it always had a whiny AC too. Looks like I will be replacing a bunch of spinny things in the near future.

Thanks to all of you who came to help! I've yet to do a proper test drive so it's not quite over, but idling is perfect. Will be back soon when something else inevitably breaks.

[Noamit 2]

Quick update:

120kms later, the temp needle stayed right in the middle with no movement. Coolant level is stable. I think I can call it a success!

I learned a lot here. Thanks everyone, this wouldn't have been possible without this space and people 

[Eagle 1659]

Good to hear. Few other areas which can fail unfortunately so if you keeping the car be prepared. PIpes under the manifold are the hidden time bomb which can let go suddenly, so id be keeping an eye on the coolant level often if you not planning on doing an overhaul.