[travis94ZX]

I am writing this in hopes to find a cause and solution to this nightmare problem.

I am now replacing the water pump on my 2008 BMW 335i (E90) for the 4th time in a year. All of them have cracked in the exact same place on the front plastic housing. I have noticed when googling images of the water pump, some of them have rubber grommets in the bolt mounting holes. However, all the pumps I have purchased/warrantied do not have grommets (or holes big enough to put them in). Is there supposed to be some sort of vibration dampening when replacing these pumps? I am starting to think that engine vibration may be causing this. There isn't anything close enough to the pump that it could be hitting to cause it to crack, never the less, in the EXACT same spot!

I am at my wits end with this problem. Has anyone had this problem? If so, how do you fix it and prevent them from cracking!?!?

[vitan]

Same problem here. I have 3rd this year. I have no solution and idea what can cause it.

[MJ80.]

My cars done 88k kms and has done one water pump in that time, three and four in a year aint right.

[vitan]

When I replaced last one, it cracked withnin one hour...

[Miller335]

Is there a special way to install it?

Is it cracking where you have to tighten down a bolt?

[Luckystrike24]

They're cracking because the new water pumps are thinner where the bolt goes thru than the ones that came from the factory. You have two choices: BMW has new bolts that aren't as long and are metal, or you have to remove the nub from the aluminum bolts so they don't bottom out before the pump is actually tight.

[vitan]

Originally Posted by Luckystrike24

They're cracking because the new water pumps are thinner where the bolt goes thru than the ones that came from the factory. You have two choices: BMW has new bolts that aren't as long and are metal, or you have to remove the nub from the aluminum bolts so they don't bottom out before the pump is actually tight.

Second pump that I replaced was from totaled car (5k km), so that was factory pump. When pump was installed it can move in rubber nuts, wasn't tight.

[vitan]

Originally Posted by Miller335

Is there a special way to install it?

Is it cracking where you have to tighten down a bolt?

There are 3 bolts, so I don't know if there is some special way, maybe. I have only 2 bolt installed tighten very mild. I want to test the leak, so I start the car at the garage. I let the car warm up and suddenly, after few minutes, it start to leak. I thought it was some hose, but I realized that pump was cracked again... Crack is on 6 oclock when the pump is on the engine.

[Jklad]

Are you using the new updated bolts with your new wps? Or do you keep reusing the old bolts?

[vitan]

Originally Posted by Jklad

Are you using the new updated bolts with your new wps? Or do you keep reusing the old bolts?

I used new bolds, but I think it wasn't necessary, bolt was like new. But now I use steel bolds like BMW recomends. I don't think problem is with bolts, I never replaced thermostat, maybe this can cause the problem?

[blackturbo]

My new pump crapped out after a year, thankfully the part had a 2 year warrenty. I feel your pain though ..

[vitan]

Originally Posted by travis94ZX

I am writing this in hopes to find a cause and solution to this nightmare problem.

I am now replacing the water pump on my 2008 BMW 335i (E90) for the 4th time in a year. All of them have cracked in the exact same place on the front plastic housing. I have noticed when googling images of the water pump, some of them have rubber grommets in the bolt mounting holes. However, all the pumps I have purchased/warrantied do not have grommets (or holes big enough to put them in). Is there supposed to be some sort of vibration dampening when replacing these pumps? I am starting to think that engine vibration may be causing this. There isn't anything close enough to the pump that it could be hitting to cause it to crack, never the less, in the EXACT same spot!

I am at my wits end with this problem. Has anyone had this problem? If so, how do you fix it and prevent them from cracking!?!?

Do you have bmw's coolant, or some other brand? At first pump I suspected oxidation, there was some under the plastic. But when my next pump cracked immediately, it wasn't that case.

[Cloud9blue]

I am seriously lost here. What is cracking exactly? Can someone point it out?

The mounting points look to be aluminum from the pics.

https://www.ecstuning.com/BMW-E92-33...ump/ES2622810/

[Cloud9blue]

nvm, you guys are talking about the thermostat.

https://www.ecstuning.com/BMW-E92-33...ostat/ES25121/

[vitan]

http://s725.photobucket.com/user/joey_hernandez2/media/IMG_20151104_201630_zpseqapfywi.jpg.html

[travis94ZX]

To clarify, this is not a water pump FAILURE. It is literally cracking the plastic that houses the impeller. I have added a photo with a red line to indicate the location of the crack. It has happened 4 times in the last year! I just installed new motor mounts as they were worn out but NOT broken.

The water pump sits bolted to the bottom of the engine block (as all of you probably know already). It appears that there is enough clearance between the steering rack and the compressor of one of the turbos (that sits right above it).

Is anyone else experiencing this...specifically a CRACKED water pump in the location I depicted in the photo?

[Jeff@TopGearSolutions]

You guys using a torque wrench? Seems over-tightening could be the culprit.

[travis94ZX]

Originally Posted by Jeff@TopGearSolutions

You guys using a torque wrench? Seems over-tightening could be the culprit.

Now that I think about it, I don't think I used a torque wrench but I also didn't Hulk it on there either. Not sure how VDO/Continental gets away with this. VERY frustrating! I wonder if there is a way to adapt the metal water pump to these cars?

The bolt hole pattern looks the same. However, the electrical connector is different...

https://www.google.com/url?sa=i&rct=...49620169626825

[Miller335]

Not to kick you while while you're down but you need to be using a torque wrench before you start blaming the manufacture of the pump.

[Cloud9blue]

How would a torque wrench affect bolts that the installers would never touch??? The crack appears on the plastic housing, not around the mounting points to the engine...

[Miller335]

My mistake, I have not had to do one yet so I just assumed.

[Jklad]

I never torqued my wp down when i did the install. honestly with the pia angles you need to even get the freakin bolts on, how the hell would you accurately torque them down anyways? This job sucks, I can't imagine having to do it 4 times in a year. Opmust be lightning fast at it by now!!