hi all. had coolant all over garage the other day, under my wifes 2011 r56/n16. pictures on another site matched up with the drippings under the car, for what they said would be the water pump as the source of the leak. so I ordered a replacement pump and got the old one out (lowering the engine after removing the 18mm + 4x 13mm bolts from the mounting bracket made it much easier). I allowed the coolant to drain and then went to inspect/clean the opening... only to find a hard plastic ring AND a rubber ring right in the circular inlet from the block. the hard ring was sitting right on top of the inlet opening and is split (like a cheap keyring). the rubber ring is split on about 1/4 of its circumference (I will try to add pictures here in a bit, but I wanted to get this post up first). the inlet is also very rough, as if cut poorly, and the rubber ring was wedged into a rough lip along the inner part of the inlet.

so basically, I have NO CLUE where these two rings came from. the rubber ring looks like an O-ring from elsewhere in the cooling system, could it have 'migrated downstream' and gotten stuck at the water pump impeller? has anyone ever seen or noticed this before, and if so what did you do with them?

thanks in advance
D

 

hard plastic ring that was found first, after the old water pump was removed, in the mouth of the inlet opening. I am using my fingers to hold it open so the broken gap can be seen.

rubber ring that was found "wedged" between the rough edges of the inlet opening. it was under the hard plastic ring, and was twisted and bulging out of the gap I found it in.

water pump inlet opening (top left). not sure if you can see in the picture but there is a rough, almost razor like edge, that goes about 2/3rds the way around the inner lip of the opening.

sorry about the sizing, Im wiped at the moment and dont feel up to even seeing if I can adjust it.

 

There is a plastic tube that crosses behind the block into the water pump housing. Looks like you’ll need to replace it.

https://www.ecstuning.com/b-genuine-...e/11537589713/

There are other sources, but the rumors say that the aftermarket tubes don’t fit as well as the OEM tube.

 

The harder ring is the end section of the plastic pipe where it inserts the inlet of the water pump housing, and after that inlet breaks off, the o-ring is immediately behind it, that also came off. You're lucky enough that those two pieces didn't get siphoned into the impeller then elsewhere downstream into the cylinder jacket. Do yourself a favor and do what njaremka says, go for OEM tube and call it. "Some" other brands lately we've seen fellow forum folks are having fitment issues.

And while you're at it, you should replace the water pump if it's the plastic impeller version. If it's already the metallic impeller then all you need to do is replace the gasketry. I strongly recommend getting the metal impeller water pump. It's what I put in all my clients' cars nowadays.

 

Thank you both for the excellent replies, very helpful. I suspected the pieces I found were from a hose but since they'd managed to squeeze through an opening smaller than they were, I felt a little crazy. I am also really apprehensive about the roughness of the metal edge, but I cant think of a thing I can do about it. I am still wondering if it was damaged by the hard plastic piece coming through, or if for some reason mini was OK with leaving it that way for assembly.

I am also hoping one of you can tell me how 'buried' the water pipe is - is it just under the air filter housing, or am I going to be stripping away half of the back of the motor to get at it?

Thanks again!

 

intake manifold needs to come off, thermostat housing needs to come off, then re-install new water pipe (make sure on water pipe to thermostat housing connection that you insert the retainer clip), when you bolt the thermostat housing back, the housing will be pushed in to secure the water pipe in its rightful place. Then put intake manifold back.