Sudden coolant leak.

[blumpie]

The radiator light came on this morning on the way to work. It was dark and congested, but the temp Guage stayed where it should. I have suspected a small leak for some time, but i could not pinpoint it.

When i got in this morning, i could see a puddle forming under the car.... not good.

After a quick look under the hood, i saw water coming from the water pump area. I could not tell if it was coming directly from the water pump or from somewhere higher. The water pump wax nit making any noise.

Question... is there a common failure? Or does it seem like i may gave just blown a water pump gasket?

[M_3_X]

What year model and mileage are we talking about? If it's an E83, Most cooling system failures are related to the expansion tank cracking, but most people would tell you, the whole cooling system is weak and should be refreshed at around 100k miles.

My 2005 e83 on the other hand still on the original water pump at 205k miles....though I had to replace the ET last week due to cracking.

With that said, your issue seems to be related to the water pump.

[blumpie]

I have an 06 e83 with 122k - sorry bout that. IIRC, some late model ever came with a plastic thermo housing. I suppose it could be leaking downwards.

Im going to take a closer look at lunch time. I hope i can limp home.... i have a 25 mile drive in very heavy traffic.

If a cant find a smoking gun, ill start with replacing the water pump gasket, thermo, and thermo gasket.

[91e34M5]

Take a really close look at your expansion tank. The crack will be vertical and really hard if not impossible to see. The antifreeze won't necessarily leak down to the ground directly below it. It sometimes leaks down on the undertray then hits the ground at another location. Look closely at the hose that attaches to the underside of the tank. If there is anti freeze on the underside, you've probably found your leak. I had to change out my tank about 2 years ago...not saying though that your problem isn't your water pump. My 2005 X3 turned 165,000 miles today and it still has the original water pump & thermostat....and you can bet I've been keeping a close eye on them.

[blumpie]

For sure leaking from the water pump. Strange because the pump seems fine anyway. I'm surprised it would start leaking suddenly like that.

I pulled everything out and I am hard pressed to replace the water pump when Ican get a gasket for $4....

The expansion tank is fine except the float rod practically disintegrated into dust... so ill be replacing that as well.

[blumpie]

Got everything zipped up and idled the car for 30 minutes. Only used distilled water to check for leaks. Everything seemed good, so went for a ride.

About 5 miles in i had the radiator light again. Pulled over and its leaking again. Got it home and i cant find it... i don't think its the water pump this time.

Ill have to take some of the plastic off to get a better look. I wanted to keep it intact to make sure i had good air flow.

I hate these compound issues. I remember when i changed the thermostat on my e39.... i qas chasing down leaks for weeks and cost me $100 in coolant.

[blumpie]

Update on this..... i got a water pump gasket for $0.93.... best fix ever. Did a full coolant flush and replaced the expansion tank for good measure.