[BMW135iMike]

Has anyone here proactively had the water pump swapped out? I hear they go bad between 60-80k miles. I'm already at 85k. Most are highway miles, but wondering if I should replace before my car shuts down on the highway do to a pump failure causing me to totally disrupt that day(s).

What should I expect to pay for this at the dealer?

Also, I still have the original battery in the car, should I have that changed too? Almost 7 years old now. What will that cost at the dealer?

And are spark plugs really needed every 40k miles in the 335i? If I'm doing mainly highway, can I get 60K+ miles out of the spark plugs?

[nate5ks]

Change your plugs and wait on the water pump and battery unless you're experiencing problems. Usually the water pumps fail gradually and throw codes before you see anything while driving so if it starts throwing random errors then think about getting it replaced preemptively so you're not stuck on the side of the road somewhere.

[BMW135iMike]

oh i thought it was electric and basically is on and working or off and broken

[BMW135iMike]

and what about fluid changes? i haven't had anything changed except oil and brake fluid

[PA66400]

Originally Posted by nate5ks

Change your plugs and wait on the water pump and battery unless you're experiencing problems. Usually the water pumps fail gradually and throw codes before you see anything while driving so if it starts throwing random errors then think about getting it replaced preemptively so you're not stuck on the side of the road somewhere.

No, it does not fail gradually, at all. The vast majority of failures are sudden, unexpected and disable the car. Look at the posts in here - almost nobody had "codes thrown", certainly none that cause a CEL before a failure. You will have no warning except your when your car goes into limp mode (really unsafe on an Interstate, BTW), overheat alarm and engine fan running on full blast.

Get your pump replaced proactively. It will be cheaper in the long-run, as compared to a tow to a BMW dealer - do you want to do this while travelling, on vacation?! 85K miles on a 335 pump in an '07 car is just good luck, but it will run out, likely soon.

[Efthreeoh]

Originally Posted by PA66400

No, it does not fail gradually, at all. The vast majority of failures are sudden, unexpected and disable the car. Look at the posts in here - almost nobody had "codes thrown", certainly none that cause a CEL before a failure. You will have no warning except your when your car goes into limp mode (really unsafe on an Interstate, BTW), overheat alarm and engine fan running on full blast.

Get your pump replaced proactively. It will be cheaper in the long-run, as compared to a tow to a BMW dealer - do you want to do this while travelling, on vacation?! 85K miles on a 335 pump in an '07 car is just good luck, but it will run out, likely soon.

It does start failing gradually and does throw codes, except you need to scan the car with a BMW scan tool to see the codes. The codes do not throw the CEL because they are not emissions related. But you are correct the pump will eventually stop working and cause the engine to over heat.

To the OP. No one has an answer to your question because there are consistent factors that cause pump failure to point to to make a decision as to when the pump is starting to fail or will fail, other than scanning the car periodically to look for water pump failure codes. So replacing the pump pre-emptively is up to you. What I would do is have a qualified BMW independent repair shop do all the work you are planning rather than the dealer. The dealer will be much more expensive. A pump replacement (w/T-stat) should cost about $800 as a reasonable price.

[BMW135iMike]

Originally Posted by Efthreeoh

It does start failing gradually and does throw codes, except you need to scan the car with a BMW scan tool to see the codes. The codes do not throw the CEL because they are not emissions related. But you are correct the pump will eventually stop working and cause the engine to over heat.

To the OP. No one has an answer to your question because there are consistent factors that cause pump failure to point to to make a decision as to when the pump is starting to fail or will fail, other than scanning the car periodically to look for water pump failure codes. So replacing the pump pre-emptively is up to you. What I would do is have a qualified BMW independent repair shop do all the work you are planning rather than the dealer. The dealer will be much more expensive. A pump replacement (w/T-stat) should cost about $800 as a reasonable price.

Would I new pump be of a different quality and last longer than the original pump after being replaced? Also the dealer quoted me $475 for a new battery. Does that sound too high? Could an independent shop do the battery for me, even with the recoding of my car to recognize the battery?

[JunkStory]

Originally Posted by MB135i

Would I new pump be of a different quality and last longer than the original pump after being replaced? Also the dealer quoted me $475 for a new battery. Does that sound too high? Could an independent shop do the battery for me, even with the recoding of my car to recognize the battery?

yes the water pump has been revised at least once so I assume the newer ones are going to be at least slightly more durable.

[gtaccord]

I also have an 07 with 78k miles with the original water pump and battery. I am not worried about the battery but I am considering changing the pump and tstat as preventative maintenance so that I won't get randomly stranded. If I do it I will probably go for it this fall.

[bahasad]

I'm in the same boat I think...I bought my car at 73K and it's at 74K now. Though it has warranty until December or January, I am already preparing to do this at 80K just preemptively though my car shows no signs of failure

[Lifted07Duramax]

Not sure where the water pump is on these cars but I bought mine with 76k on it, how can I check it to see if its original or not?

[CBR6n335Iracer]

bought my car with 72k, now have almost 100k, its an 07 335i, i drive it agressively (just too much fun not too) and according to the dealer after reading the key history there was no mention of it being replaced. my waterpump is still going and not throwing any codes, i guess im just really lucky, but with all these warnings i will be looking into preemptively changing.
is replacing the waterpump and tstat a hard DIY?

[CBR6n335Iracer]

bought my car with 72k, now have almost 100k, its an 07 335i, i drive it agressively (just too much fun not too) and according to the dealer after reading the key history there was no mention of it being replaced. my waterpump is still going and not throwing any codes, i guess im just really lucky, but with all these warnings i will be looking into preemptively changing.
is replacing the waterpump and tstat a hard DIY?

[Jklad]

Hi, my WP failed at 93k. After about 85k your driving on borrowed time, and hopefully it will not fail at a bad time or location. I would proactively replace WP and Tstat every 80k, if you make it that far.

Is it hard? Not necessarily, just can be a huge PIA to reach bolts.

[Henrik]

I have an 07 E92 and the pump went out at 46k km and no it does not gradually fail, it just all of a sudden happens.

[nate5ks]

Originally Posted by Henrik

I have an 07 E92 and the pump went out at 46k km and no it does not gradually fail, it just all of a sudden happens.

Did you scan for codes regularly? If not you would not know if it fails gradually or not.

[Meeni]

If you can read codes (internal BMW codes, not generic codes, so you need special tools like INPA or BT reader), then do not change it until you start seeing codes about low flow.

Also be attentive to the radiator fan blowing full force very often. This is not normal and does indicate that the pump is failing.

Other than these two subtle signs, it does die without much warning and leave you stranded. If the part was not that expensive, it would make sense to pro-actively change it, but at the price it cost you may want to get the most you can out of it; while most die miserably between 50k-80k, some last forever.

The Tstat design changed sometime ago. It was metal cast, it now is plastic. If you have an older (pre-LCI?) model with a plastic Tstat, it has been replaced, probably due to a first pump failure. The Tstat is solid and is rarely failing on its own.

[MBP0202]

Hi MB135i,

Even though I'm in the n52 boat, I'll chime in here...


I had the water pump & t-stat (flushed coolant) replaced proactively at 74k miles. I helped my REAL mechanic do this as I would have screwed it up on my own somewhere down the line. I agree with scanning the car for phantom codes, my indy has the AutoLogic software. I just decided to get it done since it was going to fail eventually and leave me stranded.

We figured do it proactively, since we were doing a lot of things such as the oil pan gasket, replacing front differential (noticed a 20% drop in fluid level due to a small leak) & pinion seals. With some volunteered helping labor, I got this all done for $600


As far as a battery goes, I replaced the original battery in the car for the first time at 70k. It was a lead acid battery and it lasted just about 6 years. It could have made it a bit longer but I didn't want to try to get through another winter season without it being replaced. If you live in a warm place or the car always gets in a garage then maybe push it 7...

I had it done at an indy and they replaced it with an AGM battery and it cost around $350 with programming & registration.

I did the VCG and spark plugs at 76k and the plugs looked fine, could have pushed it to 100k. But again that is on the n52 motor.


Hope this helps.