|
|
|
|
|
|
BMW Garage | BMW Meets | Register | Today's Posts | Search |
|
BMW 3-Series (E90 E92) Forum
>
Signs water pump is ready to fail?
|
|
08-16-2011, 08:41 AM | #1 |
Colonel
818
Rep 2,869
Posts |
Signs water pump is ready to fail?
seems the most common issue with BMWs - atleast e90 related - seems to be the electronic water pumps and there $500 cost of replacement.
water pumps should not be that much, oh well. but are there any tell-tale signs that your pump is going out? i know right about the 100k mark is when they start acting up, I don't have half of that, but just want to keep an eye on it over the next year or so just in case anything starts acting up. since there are no water temp gauges how can I keep track of this? if they scan my CPU are there any error codes there would point to the water pump? thanks.
__________________
2019 X3 m40i:Carbon Black:Executive:Premium:Adaptive:Vernasca:699M:HK: Ambient:IND trim:M Mirrors:15mm spacers:Maxton lip:20% tint windows/pano:dsg paddles:TLG mudflaps
2008 328i E90 Jet Black:6MT:RWD:Premium:Sport:Xenon:MTEC V3 AEs:Front Splitters:CF spoiler:19" VMR FF v710 |
08-16-2011, 12:18 PM | #3 |
Banned
173
Rep 3,415
Posts |
Glim is correct. Read the link. But to summarize: I accidentally discovered the pump low speed fault code in the ECU during another maintenance activity several months after it occurred. The first fault code showed up around 138,000 miles. I cleared them. The second instance of codes came up at around 145K (IIRC). I cleared them. Then the pump died on a 100 degree day about a month ago now, at 149,500 miles. The detail to all this is in the thread Glim referenced. I drive about 40,000 miles a year, so this all happened in the past 5 months or so.
My advice is if you discover the codes with a scan (using a BMW-compatible scan tool) change the pump soon after because it will eventually fail. I dissected my pump and can only surmise the failure is related to over-heated electronics. My pump spun just fine and the plastic impeller looked as good as new. The electronics smelled burnt. There was a fult code once the pump failed that said "Electronics - 77 Deg. C." There is no warning when it is about to fail. It fails, the car overheats, the idiot lights light up. It's a great idea to have an electric water pump, but a poor design implementation on BMW's part. |
Appreciate
0
|
08-16-2011, 01:55 PM | #4 | |
Colonel
818
Rep 2,869
Posts |
Quote:
Very dumb there is no type of warning. Going from a perfecting running car 1 minute, to an overheated-get the hell off the road-turn my engine off-car the next is quite scary. Just think about stop and go traffic on a major highway! what solutions are there to the scan tool? I do not "mod" my car a lot, or track drive, or even drive that hard. I don't do a lot of work myself, but would like to keeps tabs on my car - and water pump. Is there a "cheaper" solution than buying a $200 scan tool just to read some codes? isnt there a way to hook up a laptop or something for much cheaper? others that have had pumps fail, does the car act the same way? One minute fine, the next its overheating?
__________________
2019 X3 m40i:Carbon Black:Executive:Premium:Adaptive:Vernasca:699M:HK: Ambient:IND trim:M Mirrors:15mm spacers:Maxton lip:20% tint windows/pano:dsg paddles:TLG mudflaps
2008 328i E90 Jet Black:6MT:RWD:Premium:Sport:Xenon:MTEC V3 AEs:Front Splitters:CF spoiler:19" VMR FF v710 Last edited by AllBlackBimmer; 08-16-2011 at 02:00 PM.. |
|
Appreciate
0
|
08-16-2011, 01:56 PM | #5 | |
Banned
202
Rep 2,740
Posts |
Quote:
Did you need to change your thermostat too? |
|
Appreciate
0
|
08-16-2011, 02:59 PM | #6 |
Captain
21
Rep 780
Posts |
You would think because it is electronic they would have a smaller backup pump that would only kick in once the main one failed.
It could illuminate the yellow warning and put the car into limp mode. But they didn't |
Appreciate
0
|
08-16-2011, 09:07 PM | #7 |
Banned
173
Rep 3,415
Posts |
Yes, but I did it 6 months before the pump failed. The problem is the pump costs $400 just for the part. It's hard justify replacement at 100K, or whatever mileage, since there is no information from BMW as to the mean time between failure of the pump. As I said, lousy execution. Since it is not belt driven, you'd expect it not to fail for the life of the car.
|
Appreciate
0
|
08-18-2011, 12:20 PM | #8 | |
Banned
202
Rep 2,740
Posts |
Quote:
The guy at the parts department, said if your going to change the pump you might as well change the thermostat too. |
|
Appreciate
0
|
08-18-2011, 04:36 PM | #9 |
First Lieutenant
21
Rep 364
Posts |
Does the frequency of coolant change has anything to do with water pump and/or thermostat failure. From Eninty's thread, I understand that the coolant was changed around 75K, if I remember right. Anyone has any exprience with coolant flushes and water pump failure. I am a power electronics engineer and I work on electric motors. I can tell you that the motors are well built, but the electronics is not. Silicon electronics do not last long when driven past 70C ambient, which in most cases results in 125C at the semiconductor junction.
|
Appreciate
0
|
08-18-2011, 05:05 PM | #10 | |
Captain
21
Rep 780
Posts |
Quote:
Wouldn't this produce a higher failure rate in hotter temperates? |
|
Appreciate
0
|
08-18-2011, 05:17 PM | #11 |
First Lieutenant
21
Rep 364
Posts |
Without knowing their design, it is hard to predict the junction temperature. My guess is that there might be a feedback loop in the design, whereby the flow rate of the coolant is increased (up to some maximum, of course) if the ambient temperature increases. 70C is a generally accepted "case temperature" of an electronic circuit board that processes power. In the water pump case, the circuit is likely to be a DC to AC converter (DC from battery and AC to drive the motor and to control its speed).
Last edited by queensfield; 08-18-2011 at 05:18 PM.. Reason: typed too fast |
Appreciate
0
|
08-18-2011, 06:08 PM | #12 |
Freight Dawg
104
Rep 2,103
Posts |
Well, mine died a 5000mi and my new pump is still here at 165,000 mi. They have revised the pump at least once.
__________________
--Marcelo
'06 Arctic Metallic 325i | Sport Package | 6MT | Dinan Stage III suspension | Dinan exhaust | 330i manifold swap! Click here! | Active Autowerke tune | 135i Brake Calipers | Deiselboost caliper brackets | E46 M3 front rotors |
Appreciate
0
|
08-18-2011, 10:23 PM | #13 |
BMWCCA 149159
38
Rep 847
Posts |
BMW electric water pumps are a lot more reliable than the mechanically driven models in the other 6 cylinders that last around 60K before you better replace it.
The electric pump is perfect for the application given higher volume when warm or hot and lower volume when cold or cooler out. As is true with anything else in life BMW didn't build the pump, they out sourced it. Also if you drive an E93 like I do the water pump isn't your biggest concern, the HPFP is. $400 for the pump every 100K miles? OK well it isn't a cheap car and BMW as well as every German car I ever owned require maintenance. I will step up to that and just enjoy the ride. I know that I have been running Evan plus waterless coolant in my M3 for the last 3 years and in my diesel truck unpressurized for the last 7 years and have suffered zero issues regarding water pumps... |
Appreciate
0
|
08-19-2011, 02:34 AM | #14 |
Major
160
Rep 1,307
Posts |
|
Appreciate
0
|
08-19-2011, 12:57 PM | #15 |
Major General
124
Rep 5,627
Posts |
|
Appreciate
0
|
08-20-2011, 06:21 AM | #18 | |
Banned
173
Rep 3,415
Posts |
Quote:
|
|
Appreciate
0
|
08-20-2011, 11:40 AM | #19 |
First Lieutenant
21
Rep 364
Posts |
The most common coating used in high end electronics is parylene. It is a good insulator (dielectric) to prevent local arcing- other common insulators do not go down conformally and eventually cause local arcing over time as the insulation degrades. Parylene has low vapor pressure but may evaporate over time. Also, if there is a black-colored material underneath the electronics module, where it is bolted and welded, it is most likely a thermal interface. It is normally used if the housing is plastic (a metal housing won't need it). Do you see any degradation of the interface material, if it is present?
|
Appreciate
0
|
08-20-2011, 01:40 PM | #20 | |
Banned
173
Rep 3,415
Posts |
Quote:
Last edited by ENINTY; 08-20-2011 at 01:46 PM.. |
|
Appreciate
0
|
08-22-2011, 06:51 PM | #21 |
Banned
202
Rep 2,740
Posts |
|
Appreciate
0
|
08-23-2011, 03:56 PM | #22 |
First Lieutenant
21
Rep 364
Posts |
BMW says the following regarding their pumps- "Original BMW Water Pumps remain absolutely reliable even under extreme temperature conditions. Tailored to the specific engine, precisely machined and intensively tested, their main distinguishing feature is a long service life. Even at 7,000 rpm and after 100 hours of continuous testing, they must lose no more than 12 grams of water. So the only time that you will see an overheated engine is when you pass one".
From this, it appears that the pump itself is quite reliable but the electronics driving it is not. BTW, this is a standard test on water pumps and is known as ASTM Test D2809. The test is run at a temperature of about 113C (235F) and mainly tests for cavitation (formation of high pressure gas bubbles that can create pits in the pump material and lower the cooling efficiency by decreasing the contact area with the flowing liquid). Such a test may not have tested the electronics. If there is a way to change the electronics alone, then the expense of water pump replacement can be lowered. |
Appreciate
0
|
Bookmarks |
|
|