Save yourself up to $200 and some headaches - Electric Fuel Pump PM

Replaced mine today as it was a nice day out and I don't like the thought of my car on a tow truck. 112K miles, pump was $120 from BMA and a new gasket for a few bucks. It was pretty easy took about 40 minutes from start to finish being slow and careful.

PM job?

Have you noticed any improvement in driveability?

Make sure you also get your fuel filter replaced soon in not already done so.

I recommend 30k fuel filter change increments.

I think you will be happy you chose to do this now and not have to do the job in the dead of Winter.

Yes PM job, I replaced the filter a few thousand miles ago. It seems to drive the same, great as ever. One less thing to worry about!

Thanks for the update.

I agree that PM pump is around age 7-8 is a smart and cost effective thing to do.

The funny thing is people will spend almost as much money and far more time on a CCV replacement that will not leave you stranded, will likely cause the CEL to come on and maybe the engine to run a bit rough, but they complain about PM on the fuel pump that is much easier to replace than the CCV and WILL leave you stranded!

Are 2006 models outside this issue? I have a low mileage (42k) E46 M3. If the fuel pump is one of the problematic ones, I'd rather replace it now than worry about a failure.

The owner's manual actually states damage can occur if below a range of 35 miles of fuel left which is interesting. Never had a 'low fuel' = damage warning in any of my owner's manuals out of 10+ cars I have owned.

Originally Posted by alkemyst

Are 2006 models outside this issue? I have a low mileage (42k) E46 M3. If the fuel pump is one of the problematic ones, I'd rather replace it now than worry about a failure.

The owner's manual actually states damage can occur if below a range of 35 miles of fuel left which is interesting. Never had a 'low fuel' = damage warning in any of my owner's manuals out of 10+ cars I have owned.

It is strange tho isn't it that we're not allowed to use all the gas in our tanks without risking the car. Because the fuel over the pump helps cool the motor.

jfoj has explained before that M3 pump is a very different and more expensive pump.
Wonder what he'll say about the failure rate and PM?

I believe the M3 pump is very much like the M5 pump?

The M cars do not have an integral fuel pressure regulator built into the fuel filter. They also run a much higher fuel pressure, I believe up to 70-75 PSI?

The issue with running the tank too low is risk of fuel starvation during hard corning and possibility of leaning out the fuel mixture and causing the combustion temps to quickly climb.

The M cars also have a fuel baffle right at the fuel pump pickup to help reduce fuel starvation during hard corning.

The fuel does a few things to help out the pump and injectors.

The fuel actually lubricates the fuel pump and injectors and also cools the pump and injectors.

If you starve the fuel pump too much, you risk reduced cooling and lubrication as well as putting the engine in a risky situation where the combustion temps can quickly rise and cause knocking/detonation and possible engine damage if continued to be driven hard.

I also believe the M pumps may not last as long as the non M pumps due to their increase pressure and more demanding application??

This is my point of view based more on the E39 M5 as I have had my hands on many more of them than the M3.

Originally Posted by Stinger9

Ding! Ding! Ding! Ding!

You're the tenth one with a working original pump to report this week. You must have known that this board pays a $1000 door prize for your feat!

Where can I claim my prize?

Originally Posted by jfoj

Just a matter of time my friend!

We will be waiting to hear your story how you were not inconvenienced in any way, that the pump quit in your driveway when you were planning on being out of town anyway so you ordered a new on on line, went out of town, then when you came back late the next Friday your new pump was waiting at the house for you to install over your leisure time during the weekend. It also only took you 10 minutes to change as you had all the tools next to the garage door and you had read out changing the pump so many times.

My original fuel pump is still going strong.

Originally Posted by TrickTizzle

Where can I claim my prize?



My original fuel pump is still going strong.

1) How are you certain it's your original fuel pump. What confirmation do you have? Are you the original owner or have you confirmed the date stamp on your fuel pump? Highly doubt it.

2) Assuming 1 is true, what does "going strong" mean, exactly? Everything is going strong until it leaves you stranded. Have you verified that fuel volume and pressure is up to spec?

3) Assuming 2 is also true, I wouldn't be bragging about being on an original fuel pump. Unless you own your own towing company and/or live at home with your parents, I would make changing your fuel pump at this point a priority in your E46 ownership given the threads/reports of failures we get on a daily basis here.

He likely has his original DISA, CCV, cooling system and battery too!!

Do not worry the fuel pump lightening strike will get him at -10F when he has to go to the job interview first thing in the morning and there is 10 inches of snow on the ground!

He might be a bit luckier as it does appear earlier pumps may be a bit more robust, but they are not so robust to last forever!

It is a DC brush motor, it is destine to fail due to commutator wear at some point!!

I am sure we will hear the story that it happens at the most convenient time with only 1/2 tank of fuel, the car is in his driveway and BMA parts gets him the parts the next day by 9 am without expedited shipped!

Originally Posted by TrickTizzle

Where can I claim my prize?

Send me self-addressed stamped envelope and I'll return your bonus!


My original fuel pump is still going strong.

Might be an amazing feat except that we have no idea what your mileage it? Could be you have a low mileage garage queen with 16,000 miles.

The truth will set you free.

Last few times i started my car it has had a hard start and idle'ed poorly untill I drove it,now it let me sit. No codes! So could fuel pump total failure (at 1/2 tank, 130K) be my issue?

Sounds like a likely suspect. $3 can of starting fluid will answer the question for sure. Only the M cars may trigger a code and it is usually for the relay when it is actually the pump!

Read the first post in this thread.

On my scan tool live date there was an incremental reading in the Evap Sys, tis has been there for as long as i owned this car

Could check for fuel pressure at the rail.

Originally Posted by E46Mango

1) How are you certain it's your original fuel pump. What confirmation do you have? Are you the original owner or have you confirmed the date stamp on your fuel pump? Highly doubt it.

I have complete history and all maintenance records of the vehicle.
Let me assure you, its the original fuel pump, and its currently still going strong.

2) Assuming 1 is true, what does "going strong" mean, exactly? Everything is going strong until it leaves you stranded. Have you verified that fuel volume and pressure is up to spec?

Its completing its task. Good enough for me.

3) Assuming 2 is also true, I wouldn't be bragging about being on an original fuel pump. Unless you own your own towing company and/or live at home with your parents, I would make changing your fuel pump at this point a priority in your E46 ownership given the threads/reports of failures we get on a daily basis here.

Nope, fuel pump will get replaced if it fails, just like any other part.

Originally Posted by Stinger9

The truth will set you free.

What address shall I mail the envelope to?

Originally Posted by jessejet

Last few times i started my car it has had a hard start and idle'ed poorly untill I drove it,now it let me sit. No codes! So could fuel pump total failure (at 1/2 tank, 130K) be my issue?

You probably need to change the pump and filter. The hard start and rough running was probably the filter more than pump. But the pump has probably died now too. I'd replace both.

Originally Posted by TrickTizzle

My original fuel pump is still going strong...

So was mine, until the day it was not. Current status does not indicate future performance for these things.
There is nothing wrong with waiting until it fails, but I would keep one handy, along with the tools needed to replace it. That is exactly what I did, and I was back rolling within about 45 mins.

wow this fuel pump issue isnt a small one. im going to replace mine now to. its still original. i wanted to replace it as the fuel level senders is crazier than a drunk guy drinking metholated spirits. but after reading all this i just gotta say thanks that its still working! cars got 220000km on clock. chit i gotta replace it soon hahaha.

i beleive in preventative maintanance on a car. cuz who likes to get stranded and think to yourself, wow those guys were right!!

Originally Posted by MJLavelle

So was mine, until the day it was not. Current status does not indicate future performance for these things.
There is nothing wrong with waiting until it fails, but I would keep one handy, along with the tools needed to replace it. That is exactly what I did, and I was back rolling within about 45 mins.

And one more note: don't run with your car more than 3/4 full in the tank at all times. If stranded and a full tank, the gas will overflow when you remove the pump from its well.