Is direct injection inherently unreliable?

BMWUltimateDriv3r · 08-04-2011, 08:43 PM

I know it achieves better MPGs and a lot of automakers are moving towards it but will it cause a lot more cars to break down?

wisesoul · 08-05-2011, 05:35 PM

FSI V8s in general have problems with carbon build up in the valves. My RS4 had its valves cleaned once. Found a fair amount of debris and deposits in there. Not sure about other manufacturers

UltimateBMW · 08-05-2011, 05:38 PM

Quote:

Originally Posted by wisesoul

FSI V8s in general have problems with carbon build up in the valves. My RS4 had its valves cleaned once. Found a fair amount of debris and deposits in there. Not sure about other manufacturers

Some older Audi's were pretty notorious for this, as well as engine sludge.

As far as in general across brands, no idea.

ssunnylee24 · 08-05-2011, 06:49 PM

It's bad.

stickypaws · 08-05-2011, 08:19 PM

DFI is not "inherently unreliable."

Oil in the PCV system is the problem with certain DFI motor designs. And first generations did not include effective oil separators. A properly designed oil separator will keep coking issues at bay (like Porsche and Mercedes are now doing.) DFI design and technology gets more advanced every year, and it's here to stay. There are a lot of advantages to a properly designed DFI motor; much more energy efficient with increased performance, and it can also run lean.

Again, there's a lot of R+D going into DFI and it is not going to be "inherently unreliable." Certainly no more so than a NA motor versus a modern FI motor (will there be any NA motors left soon?) These concerns also came up when carburetors started to go the way of electronic fuel injection. The argument was that EFI was never going to be as reliable as an old fashioned carburetor.

08-04-2011, 08:43 PM	#1
BMWUltimateDriv3r First Lieutenant 90 Rep 324 Posts Drives: '08 328xi Join Date: Apr 2011 Location: NY iTrader: (0)	Is direct injection inherently unreliable? I know it achieves better MPGs and a lot of automakers are moving towards it but will it cause a lot more cars to break down?
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08-05-2011, 05:35 PM	#2
wisesoul Savoir Faire 83 Rep 1,772 Posts Drives: 2013 BMW M5 Join Date: Aug 2010 Location: Los Angeles, Ca iTrader: (0)	FSI V8s in general have problems with carbon build up in the valves. My RS4 had its valves cleaned once. Found a fair amount of debris and deposits in there. Not sure about other manufacturers __________________ Current: Alpine White F10 M5\|H&R springs\|12mm/10mm spacers\|Eisenmann Race Sold:Imola Yellow RS4-KW V3\|MTM 10mm spacers\|Hotchkis rear sway bar\|APR Stage 1\|Milltek Catless\|RNS-E\|Euro RS4 Flat bottom Steering Wheel Sold:E46 323i
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08-05-2011, 06:49 PM	#4
ssunnylee24 Private 3 Rep 89 Posts Drives: VW GTI Join Date: Aug 2010 Location: Orange County, CA iTrader: (1)	It's bad.
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08-05-2011, 08:19 PM	#5
stickypaws Dictator 55 Rep 1,811 Posts Drives: people crazy Join Date: Mar 2008 Location: where you want to be iTrader: (0)	DFI is not "inherently unreliable." Oil in the PCV system is the problem with certain DFI motor designs. And first generations did not include effective oil separators. A properly designed oil separator will keep coking issues at bay (like Porsche and Mercedes are now doing.) DFI design and technology gets more advanced every year, and it's here to stay. There are a lot of advantages to a properly designed DFI motor; much more energy efficient with increased performance, and it can also run lean. Again, there's a lot of R+D going into DFI and it is not going to be "inherently unreliable." Certainly no more so than a NA motor versus a modern FI motor (will there be any NA motors left soon?) These concerns also came up when carburetors started to go the way of electronic fuel injection. The argument was that EFI was never going to be as reliable as an old fashioned carburetor.
	Appreciate 0 Quote