M62TU New Water Pump Leaking
 

My water pump seized. I immediately shut down, before my belt even broke. The belt smoked a lot, but didn't run long enough to break. Coolant dumped everywhere. It was tough to tell at night where the coolant was coming from. When I took the failed pump out, part of the bearing was actually sticking our the front of the pump. So assumed it was coming right out of the shaft.

I installed a new pump, and proceeded to fill the coolant. When I got to about 2 gallons, it started dripping from the front of the engine. It seemed to be from around the pump. I could even see coolant around the gasket at the top of the pump, and possibly some pooling towards the front of the valley under the intake manifold. Not sure if coolant on top of the engine may have already been there from yanking the upper hose, and dumping some coolant in there.

I assumed I must have torn an o-ring, ripped the gasket, etc. So I bought a new gasket and o-rings, tore the whole thing down again, and meticulously re-assembled everything. The o-rings and gasket I originally installed looked perfect. I started filling the coolant again, and the same thing is happening. I hit two gallons and it pours out the front of the engine. I can't quite tell where it's coming from, but it's not a slow leak.

This has me completely puzzled. If anyone has any useful suggestions, I'd greatly appreciate it.


Thanks.

I had a similar issue with a brand new pump install on my X5 after driving it for a week the pump was leaking out the shaft via the weep hole. (Defective, new pump remedied the issue.)

I'd imagine as long as there is only coolant below it it could the be same issue. I pulled off my pulley so I could see better. Hope that's gives you a place to hunt, I know a defective pump is a major PITA

Where is the weep hole located? The strange thing about this, is that it leaks until the system is dry. The only coolant that spilled when I pulled the pump was a out of the small hose going to the transmission cooler. There was nothing in either of the large hoses or the pump itself. Even when I pulled the old pump that failed, I dumped some coolant out of the other hoses and the pump itself.

The weep hole if I remember correctly is at the 6 o'clock position of the water pump shaft and is cast into the pump housing. My defective pump dropped from this location and the Wp pulley did the honor of slinging coolant

I think it's coming from the 0-rings. Has anyone ever pressure tested their cooling system? I don't want to tear this apart again, when I can't exactly nail down where I have a leak. I was thinking a hose barb, or shrader valve, on a radiator cap would work. I'd just a need a few pounds of pressure to get some air leaking.

Has anyone ever used any additional sealer around these o-rings? I know you shouldn't have to; but again, I don't want to repeat this process again. I have everything clean, lubed, the rings are not tearing, and the tubes seem to be very tight in the rings.

I've found that unless I lube the o-rings w/a water soluble lubricant (pure antifreeze works, so do other *lubes*...) that things don't go well regardless of what water pump I'm working on (E46M3 or E53 X5 [N62]).

However, check the weep hole first as it can happen that it is defective, especially if a reman'd part.

I had vaseline on the rings and tubes each time. I checked the weep hole and it's bone dry. I can see residue on top of the pump gasket and drips are coming down below both sides of the water pump. The valley pan is now dry. I must of spilled some in there while pulling the hoses. It has to be the rings dripping. It's directly underneath them. I didn't think they'd continue to drip like this for days. I have still have a stream of coolant flowing across the lot. I thought since they were near the top of the motor it would stop quicker than this.

Vasoline is petroleum based. May damage the o-rings. Use a water soluble lubricant next time.

I will next time to be safe. Although, I think these o-rings are buna-n. That makes them compatible with petroleum based lubricant, and the coolant has probably washed it away by now. I'm fairly sure that's not the cause of the leaks. I may not have cleaned up the tubes well enough for fear of pulling them loose from the rear o-rings.

I removed and polished my tubes and they still leaked. Ended up removing the water pump to replace the tubes. Second time was a charm.