New HPFP information from BMW

[Lionel Hutz]

I just got back from having HPFP #2 replaced. Apparently BMW is now telling its dealers to go through a break-in procedure on the pump. My SA described this to me as driving around 2100 RPM in a high gear with no boost. I'm not sure of the mileage they have to do this for, but between the break-in and tests they ran on my car, they put on about 40 miles. Apparently BMW is concerned that techs are testing out new HPFPs by taking the car full throttle and that this is causing pump failures. Reading between the lines suggests BMW still has no idea why these pump failures are happening, but that's me editorializing.

[Mega Man]

Interesting...also, is anyone else noticing inconsistent power? Sometimes, you'll drive your car, say shift into second and smash down on the gas pedal and feel like WHOA! Other times, you shift into second, smash on the gas pedal, and feel like, "Is this a Civic?"

[Das Ein]

Originally Posted by Mega Man

Interesting...also, is anyone else noticing inconsistent power? Sometimes, you'll drive your car, say shift into second and smash down on the gas pedal and feel like WHOA! Other times, you shift into second, smash on the gas pedal, and feel like, "Is this a Civic?"

That is what a tune is for...


But yes, I do feel a slight difference from now to then.

[Judge]

Originally Posted by Zed 2.0

Apparently BMW is concerned that techs are testing out new HPFPs by taking the car full throttle and that this is causing pump failures.

So after the 40-mile "break-in" the pumps magically work?

[Lionel Hutz]

Originally Posted by Judge

So after the 40-mile "break-in" the pumps magically work?

I don't think you're quite following. The break-in is like a break-in of any mechanical component (like your engine). BMW thinks techs taking a brand new HPFP to full pressure is killing the pump lifespan.

[imported_mega]

they work at full pressure from the second they start, they have to

however they dont flow much fuel until the rpm's are up

[135ILess]

Hi. just copy what i wrote inside an other post.

Sorry for my english..i'm french

it's funny cause i spoke with one of my collegue about the HPFP problem that BMW have with the N54 & he smile at me..and start to laught! and said to me without telling him any of the symptom..long crank starting!!! he said without hesitation...LOL i discover that before working with us he was working for Lotus & before that with Bosch company. They supply many fuel pump for many car brand. he told me that he worked especially on the same problem (Arizona GM facilities ground) for the CTS, the HHR??, Sky & Soltice duo..One of the main problem about this problem is the temp inside the engine bay, specially when the car engine is stop & re-start after 10 min after a hard session of driving. the temp get so hot under the hood that the fuel start to boil, vaporise inside the pump... now try to pump that..what's killing the pump litte by little it's the starting he said. after that, you have the problem of lubrication, the pump cannot be lubricate properly with fuel vapor. he said to me that BMW will never find a solution about this problem. he said also that he's sure that us here in Canada, there not to much problem about that cause the ambiant temps is colder in any season than you guy from state. Maybe is wrong, maybe not.. i'm just relate is statement and i'm not an expert. After that he show me a lot of picture with elise, Exige and even the Evora that he did all engine test,calibration on. locky baster!!! Just want to share this with you

[scs]

Originally Posted by 135ILess

Hi. just copy what i wrote inside an other post.

Sorry for my english..i'm french

it's funny cause i spoke with one of my collegue about the HPFP problem that BMW have with the N54 & he smile at me..and start to laught! and said to me without telling him any of the symptom..long crank starting!!! he said without hesitation...LOL i discover that before working with us he was working for Lotus & before that with Bosch company. They supply many fuel pump for many car brand. he told me that he worked especially on the same problem (Arizona GM facilities ground) for the CTS, the HHR??, Sky & Soltice duo..One of the main problem about this problem is the temp inside the engine bay, specially when the car engine is stop & re-start after 10 min after a hard session of driving. the temp get so hot under the hood that the fuel start to vaporise inside the pump... now try to pump that..what killing the pump lillte by little it's the starting he said. after that, you have the problem of lubrication, the pump cannot be lubricate properly with fuel vapor. he said to me that BMW will never find a solution about this problem. he said also that he's sure that us here in Canada, there not to much problem about that cause the ambiant temps is colder in any season than you guy from state. Maybe is wrong, maybe not.. i'm just relate is statement and i'm not an expert. After that he show me a lot of picture with elise, Exige and even the Evora that he did all engine test,calibration on. locky baster!!! Just want to share this with you

this makes sense

[SB135]

Great info! I've went through two pumps in 6000 miles, my car is less than 5 months old. I do alot of stop and go driving. I'm sure my under the hood temps are up there. So now the questions is how to keep the under the hood temps down...

[Xyloft]

The fuel pump is in the engine bay and not on the fuel tank?

[Cuz5150]

Originally Posted by SB135

Great info! I've went through two pumps in 6000 miles, my car is less than 5 months old. I do alot of stop and go driving. I'm sure my under the hood temps are up there. So now the questions is how to keep the under the hood temps down...

M3 like vented hood? Wrap the whole fuel line(s) under the hood before HPFP and after with that foil stuff. Add a fuel cooler under the intake near the HPFP, M3 like vents on the fenders................umm

[lacrosse]

Originally Posted by Xyloft

The fuel pump is in the engine bay and not on the fuel tank?

There are two pumps. One in the tank to pressurize the system and one in the engine bay to boost the pressure to the fuel rails.

Thanks for the info SCS!

[DarthColin]

Originally Posted by 135ILess

Hi. just copy what i wrote inside an other post.

Sorry for my english..i'm french

it's funny cause i spoke with one of my collegue about the HPFP problem that BMW have with the N54 & he smile at me..and start to laught! and said to me without telling him any of the symptom..long crank starting!!! he said without hesitation...LOL i discover that before working with us he was working for Lotus & before that with Bosch company. They supply many fuel pump for many car brand. he told me that he worked especially on the same problem (Arizona GM facilities ground) for the CTS, the HHR??, Sky & Soltice duo..One of the main problem about this problem is the temp inside the engine bay, specially when the car engine is stop & re-start after 10 min after a hard session of driving. the temp get so hot under the hood that the fuel start to boil, vaporise inside the pump... now try to pump that..what's killing the pump litte by little it's the starting he said. after that, you have the problem of lubrication, the pump cannot be lubricate properly with fuel vapor. he said to me that BMW will never find a solution about this problem. he said also that he's sure that us here in Canada, there not to much problem about that cause the ambiant temps is colder in any season than you guy from state. Maybe is wrong, maybe not.. i'm just relate is statement and i'm not an expert. After that he show me a lot of picture with elise, Exige and even the Evora that he did all engine test,calibration on. locky baster!!! Just want to share this with you

It sounds like the problem with the pumps is that they are suffering from cavitation during "hot" starts. In case there is someone who doesn't know what cavitation is, it is when the fuel vaporizes inside the pump due to the suction causing a drop in boiling temperature. The little bubbles that form kind of "explode" on the surfaces of the pump impeller. To make a long story short, this is pretty much catastrophic for a pump. Just my theory, but sounds plausible to me.

http://en.wikipedia.org/wiki/Cavitation

I think the only way to solve this is to add an upstream pump to boost pressure prior to HPFP, kind of a LPFP. If one exists in the fuel tank already, then crank it up a bit.

[scs]

Originally Posted by lacrosse

There are two pumps. One in the tank to pressurize the system and one in the engine bay to boost the pressure to the fuel rails.

Thanks for the info SCS!

Thanks goes to 135ILess

[atr_hugo]

135ILess, Merci beaucoup!

[Robert]

So as long as you run direct injection you will run into the same problem? Does the turbo engine run much hotter than non-turbo DFIs?

[Lionel Hutz]

Originally Posted by Robert

So as long as you run direct injection you will run into the same problem? Does the turbo engine run much hotter than non-turbo DFIs?

I'm pretty sure Mazda's DISI doesn't have anything like the problems BMW has with their direct injection fuel systems.

[bradford]

Originally Posted by Zed 2.0

I'm pretty sure Mazda's DISI doesn't have anything like the problems BMW has with their direct injection fuel systems.

2nd Audi's direct injection system. I haven't heard about mass fuel pump failures at all.

[jeremyc74]

Originally Posted by bradford

2nd Audi's direct injection system. I haven't heard about mass fuel pump failures at all.

Audi and VW both have had widespread issues with high pressure fuel pumps on their DI engines.

[jeremyc74]

Originally Posted by DarthColin

It sounds like the problem with the pumps is that they are suffering from cavitation during "hot" starts. In case there is someone who doesn't know what cavitation is, it is when the fuel vaporizes inside the pump due to the suction causing a drop in boiling temperature. The little bubbles that form kind of "explode" on the surfaces of the pump impeller. To make a long story short, this is pretty much catastrophic for a pump. Just my theory, but sounds plausible to me.
.

Cavitation is certainly bad for the pump, but I don't see how it could happen on a pump that has a pressurized inlet like the HPFP on the N54 does. Cavitation usually happens when you starve a pump by trying to pull more fluid than the inlet can supply. If the issues really are being caused by cavitation, it's likely the low pressure pump that's the actual problem, or the software controlling the two.

[zbladejr]

Has anyone compiled a summary of how many members have gone through 2 pumps already? Knock on wood, I'm at 13K miles and my first still fires up right away.

Question then is - are those that are blowing through 2 in 10K driving harder than the rest of us?

Does that make me a 135i gentle-handler?

I want to keep the HPFP....but I don't want to be a nanny driver - oh the dilemnas.

[Feyd]

I don't do much (if any) start-stop driving and mine failed on very cold start after sitting for at least 15-20 hours... Granted the damage from boiling gas could have already been done... *shrug*

i wanted a vented hood anyway.. Now maybe I can convince the wife its a must-have... LOL