Low compression?

GmikeHall · 07-16-2018, 06:17 PM

I have suspected a bad injector on the number 5 cylinder but now I think maybe it may have low compression on that cylinder. Listen to how the engine turns over in this video. The engine was running rough below 1500rpm but now it will not start at all after breaking open the fuel system to inspect the 5th injector. I have been struggling with INPA and have yet to get it working correctly so I have no idea exactly what is going on.

335dsleeper · 07-16-2018, 06:26 PM

It’ll take a minute to fire up after you open the fuel system. You need to get a battery charger on it and crank it until the air bleeds out of the rail/ injectors.

GmikeHall · 07-16-2018, 06:32 PM

I have a charger on it and I have cranked this thing for minutes (not continuously) and there is no fire at all. The lopey sound when cranking sure has me concerned and not sure why I just noticed it. This INPA has about kicked my butt and I could not find anyone in town with a diesel compression test kit to check out the compression numbers. I pulled all the glow plugs to inspect them and they all looked good to me.

ranthum · 07-16-2018, 11:06 PM

Keep cranking. Mine took forever to start after replacing vcg.

CMichael · 07-17-2018, 08:33 AM

I noticed a similar inconsistent cranking speed while turning my X5 over after a fuel filter change. I was concerned too, and hoped that it was normal and maybe just the high pressure fuel pump influencing the speed. I don't seem to get any excessive smoke or rough running after my stage 3 tune, which I assume would highlight a low compression cylinder.

GmikeHall · 07-17-2018, 12:20 PM

Good news, I kept on cranking and cranking and she came back to life.

335dsleeper · 07-17-2018, 12:33 PM

Good to hear.

Quote:

Originally Posted by GmikeHall

Good news, I kept on cranking and cranking and she came back to life.

07-16-2018, 06:17 PM	#1
GmikeHall Enlisted Member 3 Rep 36 Posts Drives: bmw 335D Join Date: Jun 2018 Location: Leesburg, GA iTrader: (0)	Low compression? I have suspected a bad injector on the number 5 cylinder but now I think maybe it may have low compression on that cylinder. Listen to how the engine turns over in this video. The engine was running rough below 1500rpm but now it will not start at all after breaking open the fuel system to inspect the 5th injector. I have been struggling with INPA and have yet to get it working correctly so I have no idea exactly what is going on.
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07-16-2018, 06:26 PM	#2
335dsleeper Banned 390 Rep 1,622 Posts Drives: 09' 335d 10'35D Join Date: Dec 2015 Location: Suffolk, va iTrader: (0)	It’ll take a minute to fire up after you open the fuel system. You need to get a battery charger on it and crank it until the air bleeds out of the rail/ injectors.
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07-16-2018, 06:32 PM	#3
GmikeHall Enlisted Member 3 Rep 36 Posts Drives: bmw 335D Join Date: Jun 2018 Location: Leesburg, GA iTrader: (0)	I have a charger on it and I have cranked this thing for minutes (not continuously) and there is no fire at all. The lopey sound when cranking sure has me concerned and not sure why I just noticed it. This INPA has about kicked my butt and I could not find anyone in town with a diesel compression test kit to check out the compression numbers. I pulled all the glow plugs to inspect them and they all looked good to me.
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07-16-2018, 11:06 PM	#4
ranthum Private First Class 24 Rep 132 Posts Drives: Looking to Buy Join Date: Jan 2015 Location: United States iTrader: (0)	Keep cranking. Mine took forever to start after replacing vcg.
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07-17-2018, 08:33 AM	#5
CMichael New Member 0 Rep 15 Posts Drives: 2009 X5 35d Join Date: Jul 2018 Location: Las vegas iTrader: (0)	I noticed a similar inconsistent cranking speed while turning my X5 over after a fuel filter change. I was concerned too, and hoped that it was normal and maybe just the high pressure fuel pump influencing the speed. I don't seem to get any excessive smoke or rough running after my stage 3 tune, which I assume would highlight a low compression cylinder.
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07-17-2018, 12:20 PM	#6
GmikeHall Enlisted Member 3 Rep 36 Posts Drives: bmw 335D Join Date: Jun 2018 Location: Leesburg, GA iTrader: (0)	Good news, I kept on cranking and cranking and she came back to life.
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