I was leaving for work and did my normal routine of checking oil and topping off but I slipped up and added about 3/4 of a quart when it was already about half way up the dip stick... stupid I know. I was in a rush so I decided to baby the car a few miles to work it drove fine. After work it idles really rough and breaks up off idle if you use too much throttle right after shift at low rpm. I drained some oil but still runs like crap. It smoths out at high rpm above 3000. But if you bog it or give too much throttle off idle it breaks up flashes the cel really quick and then takes off... any advice on what I should start checking?? It idles really rough and smells like it's super rich. Car ran like a champ before this and it well maintained sad now :(
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Sputtering off idle and low rpm shifts
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Originally posted by roguetoaster View PostM42s are just fake S14s. Sad.
I'd start with a stomp test. Not too sure that the CEL/poor running is due to oil overfill of 1/4 qt, but overfilling the oil can lead to fouled plugs and a contaminated O2 sensor.
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Originally posted by m42'd View PostI'm not sure what the s14 comment meant.. it was a simple mistake... I have autox this car but I'm not a fan of drifting. The car is not a roached out 318i either. I know I screwed up just wondering what could cause this. Plugs looked fine, all my intake hoses are new, cleaned the icv just in case. Still running crapy at idle and low rpm. How can I test the o2 sensor? What's a stomp test?
Anyway, search the stomp test, report back.
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I really am bummed though, my lil m42 has been so reliable I figured I could sell off a few cars and get by with it as a daily until I finish fixing my truck. I'm planning on getting back to tounrnamnt bass fishing so I liquidated some cars so I could afford another bass boat. As stupid as my post sounds I've actual had some pretty modded cars and do all my own work on them. Id show you pics but this forum is oldschool and I don't fuck with photobucket lol
Also it was about 3/4 qt over full.Last edited by m42'd; 03-29-2017, 09:48 PM.
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Originally posted by m42'd View Post1444
Still don't know what you mean man. I'm 34 give me a break I don't even have a twitter
Take your intake boot off and have a look at the front of the TB to see if you have a lot of oil on the throttle plates. The O2 sensor is ignored when dead cold, so if the symptoms occur next time you start the car you can probably rule that out.
Otherwise the symptoms you describe lead me to think TPS/TPS wiring or AFM issues considering the bogging/drop off idle and clearing above 3k.
Don't worry, with the knowledge base here we'll soon have your issue sorted and you'll be able to motor on for many more trouble free miles.
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After not driving for a day I started it up and let it run for about 5min and it sounded ok ao I tried to drive around the block to the gas station. When I was at the light i felt it start to loose idle again almost like it dropped a cylinder. Limped it home. Above 2500 rpm it will run but just a little off. Idle and low rpm break up and flash the cel. Basically if I stab the pedal quick it flashes cel
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Have you looked in the intake, like Rogue suggested?
(ignore his tweeting references!)
About the only thing overfilling by a quart or more will do is aerate the oil
(if it's up enough to get wound around the crank)
and the resultant froth will get sucked into the crankcase ventilation system.
In an M54, it can hydrolock the engine, but in an M42, it's more likely that it just
gummed up the MAF. Or maybe even the IAC, I guess...
Did you ever notice it dumping great clouds of smoke?
If you find oil in the intake, try cleaning everything carefully and thoroughly.
It would be hard to get oil up into the MAF's resistor pack.
If you don't find evidence of oil ingestion, then it's time for regular diagnosis-
checking plugs, smoke- testing the intake, compression, leakdown, new spark plugs and
wires,
etc,
etc,
etc...
Because not all causes are apparent...
t
also not a tweeter.now, sometimes I just mess with people. It's more entertaining that way. george graves
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the oil is not the problem. Have done the same myself, also have run it pretty low on accident... no problems so far!
Id guess your AFM is on the fritz. BAVREST can rebuild it but it will take about 3-4 weeks to send it to them and get it back. WELL WORTH IT THOUGH.
sounds like the afm is sending bad info to the DME (ecu) and giving you the poor drivability. TPS doesnt have a giant effect on the m42 from what I have gathered on my car.
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Originally posted by 5Toes View Postthe oil is not the problem. Have done the same myself, also have run it pretty low on accident... no problems so far!
Id guess your AFM is on the fritz. BAVREST can rebuild it but it will take about 3-4 weeks to send it to them and get it back. WELL WORTH IT THOUGH.
sounds like the afm is sending bad info to the DME (ecu) and giving you the poor drivability. TPS doesnt have a giant effect on the m42 from what I have gathered on my car.
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Originally posted by TobyB View PostHave you looked in the intake, like Rogue suggested?
(ignore his tweeting references!)
About the only thing overfilling by a quart or more will do is aerate the oil
(if it's up enough to get wound around the crank)
and the resultant froth will get sucked into the crankcase ventilation system.
In an M54, it can hydrolock the engine, but in an M42, it's more likely that it just
gummed up the MAF. Or maybe even the IAC, I guess...
Did you ever notice it dumping great clouds of smoke?
If you find oil in the intake, try cleaning everything carefully and thoroughly.
It would be hard to get oil up into the MAF's resistor pack.
If you don't find evidence of oil ingestion, then it's time for regular diagnosis-
checking plugs, smoke- testing the intake, compression, leakdown, new spark plugs and
wires,
etc,
etc,
etc...
Because not all causes are apparent...
t
also not a tweeter.
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