Water Leak Help Please

[DarrylvanNiekerk]

Please can someone help shed light on a water leak - e90 320i 2006.

I have been rebuilding the engine and replaced all the gaskets on the water pump. I finally managed to get the engine in and started filling with fluids only to see a dribble of water from the water pump. I separated the power steering pump from the water pump so I could get a view of where the water is coming from. The water pump wasn't leaking before I stripped it and it doesn't appear to be leaking from any of the gaskets.

Please see the below pic of the back of the water pump where it joins to the power steering pump as that is where the leak is coming from. Does this mean the water pump is damaged or can I do something about it?


https://www.bmwfanatics.co.za/media/water-leak-jpg.140/

 

[Solo Man]

I think the seal around the shaft of the pump has dried out in the time it took you to rebuild the engine and now it is leaking past the water seal (usually an O-ring) Just my 2c's

 

[DarrylvanNiekerk]

I think the seal around the shaft of the pump has dried out in the time it took you to rebuild the engine and now it is leaking past the water seal (usually an O-ring) Just my 2c's

I have a feeling it is something like that.

I think for safety sake I will have to buy a new water pump because I have my concerns about the pump anyway. I don't know how robust the impeller is and after going through a full rebuild just to have the pump die after a few thousand kilometres would be devastating.

Thank you for your input.

 

[Crash_Nemesis]

Did you replace the o-rings for all the connections going into and out of the pump?

These usually need replacing after being opened after a few heat cycles as they have lost their ability to create a good seal.

 

[DarrylvanNiekerk]

Did you replace the o-rings for all the connections going into and out of the pump?

These usually need replacing after being opened after a few heat cycles as they have lost their ability to create a good seal.

I pulled and checked each one and replaced those that looked like they needed to be but I think I will replace them all just to be sure.

The water was pouring out almost as fast as I was putting it in, this was before I even got to start the car and get the water system up to pressure.

 

[Crash_Nemesis]

I pulled and checked each one and replaced those that looked like they needed to be but I think I will replace them all just to be sure.

The water was pouring out almost as fast as I was putting it in, this was before I even got to start the car and get the water system up to pressure.

That sounds like a pretty serious leak. Possibly not the o-rings then if it’s that bad. Almost sounds like the pump has a crack or you’re not seating it correctly.

I’m assuming you’re using a new gasket when tightening everything?

Also I assume you’re tightening to the correct torque settings or just over. The torque for these bolts is not very high. I’ve just rebuilt my S54 for my M3 and the torque spec for my water pump bolts is only 10nm. I’d imagine your bolts would be around the same but probably best to confirm. Either or, I assume you haven’t under-tightened them.

May I ask the reason for the rebuild? Not due to water pump (ie: overheat)?


Sent from my iPhone using Tapatalk

 

[DarrylvanNiekerk]

That sounds like a pretty serious leak. Possibly not the o-rings then if it’s that bad. Almost sounds like the pump has a crack or you’re not seating it correctly.

I’m assuming you’re using a new gasket when tightening everything?

Also I assume you’re tightening to the correct torque settings or just over. The torque for these bolts is not very high. I’ve just rebuilt my S54 for my M3 and the torque spec for my water pump bolts is only 10nm. I’d imagine your bolts would be around the same but probably best to confirm. Either or, I assume you haven’t under-tightened them.

May I ask the reason for the rebuild? Not due to water pump (ie: overheat)?


Sent from my iPhone using Tapatalk

Definitely not the O Rings.
I replaced gaskets and followed torque settings to the letter, it isn't leaking at any joint or connection point but at the back of the pump.

The rebuild is due to a variety of issues which lead to a catastrophic engine failure - broken piston, broken (not bent) valve and scored cylinder sleeve. Engine didn't overheat. Luckily the broken bits bounced around a bit and then jumped out the exhaust so no other internals were damaged including the oil pump.

I started a thread outlining the process and need to follow up on it but due to a lack of funds I decided to rebuild the engine myself and learn in the process.

Very rewarding and frustrating and expensive and time consuming but it has kept me occupied and will result in an almost new car. A great many trips to BMW to order obscure parts and ask advice, then many orders with Imcomex and Goldwagen.

The engine rebuild was just a small aspect of what ended up being a full refresh.

 

[Crash_Nemesis]

Awesome. I went down a similar endeavor with my S54 this year and I too rebuilt the engine myself, so know all about your struggles.

Unfortunately I can’t seem to add much more advice regarding why your water pump seems to be leaking.

Is the water pump an original BMW part or one from Goldwagen?

I am not a fan of Goldwagen as it’s a hit or miss with their parts (my experience with my M3 over the past 11 years). The amount of times in the past where I’ve used their parts hoping to not spend money on the bmw tax, only screwed me as the parts either didn’t fit correctly, or just failed soon after, resulting in me having to buy the original bmw part anyway.

So for critical items such as a water pump, I would go BMW and pay the tax for peace of mind.


Sent from my iPhone using Tapatalk

 

[DarrylvanNiekerk]

Awesome. I went down a similar endeavor with my S54 this year and I too rebuilt the engine myself, so know all about your struggles.

Unfortunately I can’t seem to add much more advice regarding why your water pump seems to be leaking.

Is the water pump an original BMW part or one from Goldwagen?

I am not a fan of Goldwagen as it’s a hit or miss with their parts (my experience with my M3 over the past 11 years). The amount of times in the past where I’ve used their parts hoping to not spend money on the bmw tax, only screwed me as the parts either didn’t fit correctly, or just failed soon after, resulting in me having to buy the original bmw part anyway.

So for critical items such as a water pump, I would go BMW and pay the tax for peace of mind.


Sent from my iPhone using Tapatalk

The cleaning and prep work was not fun but I really enjoyed putting it back together and seeing it take shape.
I was really nervous the head bolts would strip out.

Cudos on your rebuild, it is a scary thing when you don't have the background or training.

The pump is original and it seemed a little suspect when I rebuilt it so am not surprised it has failed. I have found so many small issues that previous mechanics have overlooked or done incorrectly that I am now going to service and repair the car myself.

I hear you with the Goldwagen aspect and will pay BMW a visit to see what they will charge because sometimes with the Fanatics discount it works out very reasonably.
I just wish Imcomex was open but I can't wait for the new year to get the car running again.

 

[DarrylvanNiekerk]

I ended up buying from Goldwagen.
Water pump is Meyle and Thermostat is Mahle and together they were half the price than buying from BMW.