subtle low rpm knock at low rpm after tune, dp's?

mikeith · 09-25-2011, 10:05 PM

i noticed it yesterday, sounds kinda like diesel at but its so subtle that if the a/c is higher than 2/3 up or the radio is higher. i've heard its a sign of bad injector/s. i cant datalog it because i'm using a V5 and my computer is a mac(i refuse to partition it and slow it down, i have an older pc laptop but the battery is fried. thinking about picking up a used netbook.

but anyway back on subject. my car has 33k on it and has never had injectors replaced so i wouldnt be surprised it that were whats going out but and i'm not too tore up if thats what it is except for the PITA of swapping back to stock downpipes and then back to my ar's on pickup.... but the paranoid part of me remembers RIGHT after putting a cobb on my 08 sti it spun a rod bearing.(this was NOT cobb's fault, previous owner abused and i had just bought and that was just enough to push it over the edge). of course ive also just bought this 335 so i dont know how it was driven before me either, but ive never shifted over 6500.

i also thought you could check/read codes on the V5 without having to have it plugged in to datalog?!?! am i doing something wrong

blackshan · 09-25-2011, 11:11 PM

Quote:

Originally Posted by mikeith

i noticed it yesterday, sounds kinda like diesel at but its so subtle that if the a/c is higher than 2/3 up or the radio is higher. i've heard its a sign of bad injector/s. i cant datalog it because i'm using a V5 and my computer is a mac(i refuse to partition it and slow it down, i have an older pc laptop but the battery is fried. thinking about picking up a used netbook.

but anyway back on subject. my car has 33k on it and has never had injectors replaced so i wouldnt be surprised it that were whats going out but and i'm not too tore up if thats what it is except for the PITA of swapping back to stock downpipes and then back to my ar's on pickup.... but the paranoid part of me remembers RIGHT after putting a cobb on my 08 sti it spun a rod bearing.(this was NOT cobb's fault, previous owner abused and i had just bought and that was just enough to push it over the edge). of course ive also just bought this 335 so i dont know how it was driven before me either, but ive never shifted over 6500.

i also thought you could check/read codes on the V5 without having to have it plugged in to datalog?!?! am i doing something wrong

I think it is some of ur injectors. I've had the same thing happen to me but before the tune.

mikeith · 09-26-2011, 06:39 PM

Pretty sure now it's injector/s going out. Starting hiccuping pretty bad under load(even just about 1/3-1/2 throttle) at low to mid rpms on the way home from work today. I'm leaving for training for two weeks friday so I'm going to switch to map 0 and see if I can make it through the week babying it and take it back to stock and to dealer when I get back from training

mikeith · 09-27-2011, 10:18 AM

well today it didnt hiccup but once on the way to work... not sure if its due to it being 60* vs 92* yesterday or that maybe its not doing it until at full running temp because it didnt do it until i got almost to work and i actually TRIED to replicate it, and even then is was much more subtle than yesterday

09-25-2011, 10:05 PM	#1
mikeith Lieutenant 35 Rep 450 Posts Drives: 07 E90 335i. TiAG Join Date: Feb 2009 Location: lubbock, tx iTrader: (0)	subtle low rpm knock at low rpm after tune, dp's? i noticed it yesterday, sounds kinda like diesel at but its so subtle that if the a/c is higher than 2/3 up or the radio is higher. i've heard its a sign of bad injector/s. i cant datalog it because i'm using a V5 and my computer is a mac(i refuse to partition it and slow it down, i have an older pc laptop but the battery is fried. thinking about picking up a used netbook. but anyway back on subject. my car has 33k on it and has never had injectors replaced so i wouldnt be surprised it that were whats going out but and i'm not too tore up if thats what it is except for the PITA of swapping back to stock downpipes and then back to my ar's on pickup.... but the paranoid part of me remembers RIGHT after putting a cobb on my 08 sti it spun a rod bearing.(this was NOT cobb's fault, previous owner abused and i had just bought and that was just enough to push it over the edge). of course ive also just bought this 335 so i dont know how it was driven before me either, but ive never shifted over 6500. i also thought you could check/read codes on the V5 without having to have it plugged in to datalog?!?! am i doing something wrong
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09-26-2011, 06:39 PM	#3
mikeith Lieutenant 35 Rep 450 Posts Drives: 07 E90 335i. TiAG Join Date: Feb 2009 Location: lubbock, tx iTrader: (0)	Pretty sure now it's injector/s going out. Starting hiccuping pretty bad under load(even just about 1/3-1/2 throttle) at low to mid rpms on the way home from work today. I'm leaving for training for two weeks friday so I'm going to switch to map 0 and see if I can make it through the week babying it and take it back to stock and to dealer when I get back from training
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09-27-2011, 10:18 AM	#4
mikeith Lieutenant 35 Rep 450 Posts Drives: 07 E90 335i. TiAG Join Date: Feb 2009 Location: lubbock, tx iTrader: (0)	well today it didnt hiccup but once on the way to work... not sure if its due to it being 60* vs 92* yesterday or that maybe its not doing it until at full running temp because it didnt do it until i got almost to work and i actually TRIED to replicate it, and even then is was much more subtle than yesterday
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