New water pump is leaking... other Q

[jaredmac11]

2001 BMW 525i M54b25

I replaced the 'entire' cooling system minus the plastic cooling pipe a year back. Hoses, expansion tank, radiator, sensor and o-ring (that was a leak before I knew I had to replace the o-ring), water pump. I was on the freeway and I noticed my car started to overheat. Pulled over, let it cool, kept driving and all was good but it started to overheat *again* so I pulled over to the gas station and saw the expansion tank was empty. Filled it up and I noticed a leak under the car right away.

Im afraid the head could be warped now even though I didnt drive long... but otherwise, it looks like the water leak is sourcing from the water pump. Like I said, I just replaced it, I dont know why it would be leaking all of the sudden.
I will say, the belt seems tight and I just noticed that the fan clutch seems bent. The clutch is functional, but I wonder if too much stress from the bent clutch and tight belt could have caused it to spout a leak?

Do I have to replace the entire water pump or maybe just the o-ring?
Should I do a compression test before buying any parts? It was overheated under light load and for about... 5 minutes. But I really dont know since I had the engine off too when it was hot.

[Dustyleek]

Check your expansion tank for cracks and leaks and also check the radiator. Basically comb over it again once cooled off and start it and allow it to get up to temp. Doing this should see if it's something simple. From time to time you will have pin hole leaks along piping which will spray once the system is up to temp. Start small and work your way up. Its unlikely that the water pump went again. Unless the seal was misplaced when sealing the pump back of course. I would not stress too much till you trouble shoot.

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[jaredmac11]

Took another look... I filled the tank up and it right down the crank pulley. I followed the drip up and it seemed to source from the bottom of the water pump. I have a lifetime warranty with FCPEuro so Ill try a replacement and see...

[Dustyleek]

Took another look... I filled the tank up and it right down the crank pulley. I followed the drip up and it seemed to source from the bottom of the water pump. I have a lifetime warranty with FCPEuro so Ill try a replacement and see...

May be your best bet. Either a failing seal or it has gone bad and is draining from the weep hole

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[jaredmac11]

May be your best bet. Either a failing seal or it has gone bad and is draining from the weep hole

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Yep, you got it. The seal was pulling out of the pump (not the larger o-ring, but some sort of seal on the shaft). I'll replace the pump and clutch... hopefully the car didnt severely overheat.

[Dustyleek]

Yep, you got it. The seal was pulling out of the pump (not the larger o-ring, but some sort of seal on the shaft). I'll replace the pump and clutch... hopefully the car didnt severely overheat.

If you didn't let it redline out and allowed it to cool. Just keep an eye on your oil to make sure there is no mixing and make sure your not smoking. Also if it doesn't feel as strong!

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[djb2]

If you caught the overheat immediately, the engine is likely OK. The problem is with people that expect that the red light light means they have another minute or two.

Change the oil when you get a chance.

The VANOS o-rings, oil filter housing gasket and valve cover gasket have probably lost some of their life as well.

[cnn]

- What brand is the WP? I only use HEPU, in fact, the HEPU is my 1998 528i was installed in 2006 at 90K (I am now at 170K). Bone dry.
- Check thermostat housing too, sometimes it leaks from above down....

[jaredmac11]

Yea honestly I dont feel great about it. It wasnt red lined for LONG but it was in the red for 5 mins mins, both engine off or on. I mean with no coolant it had no way to properly cool the engine down. Well, we'll see what it is.

Oil filter housing gasket, vanos rings, valve cover were all done last year. I had a few things I wanted to do (tensioner and power steering lines) but I'll just do the water pump now and see if I toasted it or not. Hopefully not. Would not be surprised if the head is cracked though : (

- What brand is the WP? I only use HEPU, in fact, the HEPU is my 1998 528i was installed in 2006 at 90K (I am now at 170K). Bone dry.
- Check thermostat housing too, sometimes it leaks from above down....

I bought Saleri. Thermostat housing was done as well last year.

I bought the car and basically did tons of preventative maintenance and then @%$!ed the pooch and undid it all.

Well, if I did screw it all up, I always wanted an M54b30...

[scyrusurcys]

I replaced the water pump on my '98 540i about 3 months ago - only to find out that it was still leaking around the seal. I had to reinforce the seal with a little bit of silicon gasket sealant, turns out the included gasket was just a little too thin to make a tight seal. No more leaks!

[aw609eng]

I totally agree. I made that mistake on my 2001 330ci - cost me an engine with in 5 minutes the red, the head was toast. Anyone looking at this - take advice. If you hi the red line pull over and turn it off immediately! BTW - if you replace the water pump be sure to use the high performance aftermarket unit with the metal fan. The oem with the plastic fan .... well let's just say very bad....

[killian665]

Are y’all retarded? You got your engine temp in the red and kept driving it for 5 minutes? I hope your engine is blown up. They put that gauge there for a reason.

[aw609eng]

Are y’all retarded? You got your engine temp in the red and kept driving it for 5 minutes? I hope your engine is blown up. They put that gauge there for a reason.

WOW I thought this forum was for gaining knowledge not criticism.
Not everyone is born with the delicate intuition of how BMWs don't have the tolerance of a Chevy 350.....

Please keep it t knowledge not sarcasm.

[cnn]

...I bought Saleri. Thermostat housing was done as well last year...

- Google "Saleri water pump leaking" and you will see quite a few people with leaking Saleri.

- The HEPU water pump in my 1998 528i: installed in May 2006. It is now 12 years old and 80K miles later, zero leak.
HEPU is about $50-$60.

[killian665]

I could run a 7.3 International in the red for 5 minutes and it would blow 4 head gaskets it’d get so hot. That’s just ignorant to think you could run it that long. It doesn’t take any knowledge of anything to know that “hey this shits gettin hot, maybe I should pull over and not drive it another couple of miles.”

[ojomo]

Are y’all retarded? You got your engine temp in the red and kept driving it for 5 minutes? I hope your engine is blown up. They put that gauge there for a reason.

Poor form.

[Dave Sal]

I put some of the blame for damaged engines from overheating on BMW for buffering the temperature gauge. By the time it's in the red and the light comes on, you're already overheated and have to shut down right away. If the gauge wasn't buffered then you'd at least have a chance to see the needle moving to the right. This is why I always drive with test 7 displayed on the OBD so I can monitor the temps in real time.

[djb2]

There should be warning messages and sounds when the ECU sees a temperature excursion. If the instrument cluster is going to have a deadband in the indicator gauge, it should be raising the alarm as soon as it detects an overheat.

[cnn]

- In most vehicles, the dash temp gauge is buffered so the customer is not scared by the "normal fluctuations".

- I did a quick experiment: placed a thermometer inside the center vent, drive the car at different speeds (idle on driveway, 20 mph, 60 mph), sure enough the heat goes from 150F (driveway) to 160F (60 mph) as the engine runs higher rpm ---> there is more heat.
During all these different rpm's, the dash temp gauge is dead at 12 o'clock, so it is buffered very well.

- In the absence of better design, people driving BMW should stop the engine ASAP when the temp is just shy of 1 o'clock position

- Someone in E46 posted this nice photo...



E46 Temp Gauge.jpg

[djb2]

I can understand one reason behind the gauge deadband. With the electrically modified thermostat, the ECU is the only thing that knows the target coolant temperature.

BMW missed the chance to minimize the overheat problem. The ECU could easily compute that it can no longer control coolant temperature, and raise the alarm. It could do this significantly before a human monitoring a gauge would be able detect that something was amiss.

[killian665]

You mean like when it dings really loud and flashes up *COOLANT TEMP* right in front of your eyeballs on the instrument cluste? That kind of warning. Yeah I blame bmw too they should have made it even louder and more annoying you’re right.

[djb2]

You mean like when it dings really loud and flashes up *COOLANT TEMP* right in front of your eyeballs on the instrument cluste? That kind of warning. Yeah I blame bmw too they should have made it even louder and more annoying you’re right.

That warning (on the high cluster only) might as well say "Head warping... now".

The ECU knows well before the gauge hits the red sector that it can't control the temperature -- that the electrically controlled thermostat isn't bringing the temperature down.

[killian665]

Well about you just use the gauge? If the shits going to the red why don’t you pull over like they intended instead of driving it for another 5 minutes. I don’t see the argument here. You’re blatantly ignoring a system they put in the car to keep you from blowing up your engine and then are upset that your engine has blown up for doing so. The coolant temp warning comes on well before it hits the red.