Class action suit alleges BMW N54 turbo engine unsafe, causes Unintended Deceleration

[klier]

You might be on the money there Martin. A mate who lives on the coast has a hassle-free 135i. My dealer keeps telling me the fuel quality might be responsible, but I am not convinced. Im waiting for the 1M coupe if we do get allocations as I read it is a limited edition..

Could very well be. I live even below sea level next to the sea in a mind climate with Euro 98 fuel, and I never hear about this....

 

[chonkoa]

Even the N63 powered cars suffer of HPFP failures?!

Yep, both actually.
Before that, they had to change the secondary oil pump last year.

 

[Mr Robert]

This doesn't sound good. It's going to cost them.

Naa... it's a good thing. Because it's only when it costs them a shit load that they pay attention. I hope BMW get hit really, really hard for their sloppy and ignorant work. Next issue up: the catastrophy that is the PSA engine.

 

[Bartek S.]

several consumers reported their BMW's going into 'limp mode.' They also complained of excessive power loss and 'turbo lag,'

I personally never experienced these issues on my 335i convertible. Engine has a small turbo lag but it’s very small and barely recognisable. My car performs very well, great acceleration and speed. Not like M5 but different very pleasant feeling. My wife and I we are having no problem (so far) with our 335i and we rely enjoying it. I know for sure that might be an issue of the quality of the gas we have in North America. I personally use only 94 octane fuel (best available on the market) for my cars and I can feel a different when I put cheaper gas into my tank.

 

[chonkoa]

I personally never experienced these issues on my 335i convertible. Engine has a small turbo lag but it’s very small and barely recognisable. My car performs very well, great acceleration and speed. Not like M5 but different very pleasant feeling. My wife and I we are having no problem (so far) with our 335i and we rely enjoying it. I know for sure that might be an issue of the quality of the gas we have in North America. I personally use only 94 octane fuel (best available on the market) for my cars and I can feel a different when I put cheaper gas into my tank.

Do you get your gas from Husky because AFAIK it is only Husky that sells 94 octane rating here in Alberta.

 

[Bartek S.]

Do you get your gas from Husky because AFAIK it is only Husky that sells 94 octane rating here in Alberta.

Only Petro Canada sells 94 in Quebec.

 

[bmwownage]

This doesn't happen to bi-turbo V8s right? hopefully this problem doesn't persist onto the 1M, would be an absolute nightmare, and a joke.

 

[Mr Robert]

Only Petro Canada sells 94 in Quebec.

There must be different ways to meassure octane, right? Because here in Sweden, you can't get less than 95 and most manufacturers recommend using 98. I have heard before that these issues could be down to fuel quality but I'm not sure.

 

[coolraoul]

Yeah, in Europe (at least, in France, Germany and Romania for sure), the 95 octane is the cheapest you can get, while many carmakers recommend using 98 in every engine this side of a cheap 1.4 delivering 50hp...

There are even some stations where you can get gas with a 100 octane rating.

 

[martinbo]

It's pretty much a documented fact (well at least here in SA amongst our leading technical correspondents) that turbocharged engines are more prone to: limp-mode, turbo-failure and other related mechanical failures than naturally aspirated engines in less than optimal ambient conditions.

Turbocharged engines - by their very nature - operate in an "artificial" state of tune. By this I mean that the influence of software parameters to determine engine output is much greater than in an NA engine. In a turbo'd engine - it's software parameterisation in the engine management system that limits output in accordance with the mechanical design tolerances determined by the manufacturer to be "safe limits" through exhaustive research and testing.

Clearly, BMW haven't been able to test and cater for all ambient conditions and input factors. Any suggestion I might be able to offer as a possible cause for HPFP failure would be pure speculation but what I can say is that in high-altitude, low-fuel quality, high temperature environments turbocharged engines have empirically been shown to be more prone to failure than in optimal conditions.

Whilst a turbocharged engine is designed to create its own ambient conditions (pressure (turbocharger) and temperature (intercooler)) in order to achieve parameterised outputs, external factors still have an influence. The thinner air at altitude can cause turbocharger overspeeding for example as the software tries to extract the necessary boost pressure in order to deliver the required output.

It seems plausible to me that the HPFP is "overworked" in certain conditions as the engine management system attempts to extract the deemed output from the engine. In the case of the N54, these little turbochargers have no problem in creating the necessary boost levels but perhaps the fuel delivery system is then taxed beyond manufactured tolerances. In attempting to meet the power demands from the engine the HPFP is purely overworked and fails. Again, this is guesswork, an engineer at BMW (Warot where are you?) would be in a far better position to enlighten the community.

 

[coolraoul]

But it that case, wouldn't BMW have made limitations (via the calculator) to ensure neither the turbochargers not the high pressupre pumps are overworked? I mean, they should have included a rev-limiter for the turbo and a fuel delivery max. for the pump, shouldn't they?

I think the problem is similar to those diesel common-rail pumps that are failing massively when the engine nears 100.000kms, it's a matter of inferior fuel quality and excessive sensitivity to any dirt or anything in the system...

Those super-efficient systems work well in the laboratory but IRL it's another story... Especially after x Kkms and x years.

Just that here, this is a new system that maybe has been insuficiently tested.

 

[Mr Robert]

They should have and could have. problem is, then we would have much lower output in markets with less than perfect weather and/or lower quality fuel. That's not looking good. Better to just run on...

It's another story that some countries have very low quality fuel. I wish all could have as good fuel as in Germany. Here in Sweden, we put a lot of ethanol in the petrol, that can't be good in the long run.

 

[Bartek S.]

There must be different ways to measure octane, right? Because here in Sweden, you can't get less than 95 and most manufacturers recommend using 98. I have heard before that these issues could be down to fuel quality but I'm not sure.

There is no different measure of the fuel in octanes, we just have cheaper gas in North Am. Gas is not refine as the one in Europe and that (I believe) can cause all this problems - limp-mode, turbo lag and other related mechanical failures.

 

[Beemer B773ER]

I personally use only 94 octane fuel (best available on the market) for my cars and I can feel a different when I put cheaper gas into my tank.

Yeeesh!! Damn I feel bad for even considering filling my 328i with 87 octane.

Best we get around here is 91.

What's the price per gallon for 94 over there Bartek ?

 

[chonkoa]

This doesn't happen to bi-turbo V8s right? hopefully this problem doesn't persist onto the 1M, would be an absolute nightmare, and a joke.

I had the two fuel pumps on my X6 changed 2 months ago- so the V8s are not immune to this disease.

 

[Kowalski]

HPFP failure perhaps?

 

[Beemer B773ER]

HPFP failure perhaps?

Well, from what I've read on the issue, a HPFP failure doesn't mean that your engine completely shuts down and you end up stuck on the side of the road. You can still drive the car home or to a dealer..and still drive it after that (at your own risk of course).

Of course in that photo, if the M5 did suffer a HPFP failure, they may have pulled the car over immediately because at that time they would be unsure of the exact problem...but considering the endless occurances of this failure I'm sure BMW are taking much greater effort to ensure it doesn't plague the M5 and other upcoming M models. So coming full circle, yeah it could have been a HPFP failure to find out the maximum tolerance for the pump and other components in the engine and fuel-delivery system.

 

[Giannis]

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[Mr. Mercedes]

This is not good and kind of puts a damper on the 'best engine in the world' claims.

When this engine is operating normally it is absolutely brilliant! But now I'm kinda glad I opted not to get a 135i or 335i. Especially with not much time remaining on their warranties.

Is this one of the reasons the engine was superceded rather quickly?

 

[Bartek S.]

Yeeesh!! Damn I feel bad for even considering filling my 328i with 87 octane.

Best we get around here is 91.

What's the price per gallon for 94 over there Bartek ?

Price is 14 cents more per liter than 91 octanes. My X5 I feel times to times with 91 oct but never with 87. M5 and 335i always with 94.