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Discussion Starter #1
Hi everyone,

Driving to the airport this afternoon, at 70mph, my '04 325ci decided to kick on the EML light and into limp mode. After pulling over, shutting the car off and back on, all was well. I continued the other hour to the airport. Upon getting to the airport I popped her bonnet to have a peek and all seemed sound. MPG on the trip was good as usual, around 28mpg.

I've owned the car for 1.25 years and it's never had a hiccup. I fear this is a sign that a gremlin is penetrating my BMW.

My thoughts are fuel filter and fuel pump. I have 158k miles and have no record of these being changed. Would my symptoms indicate one of these two neglected parts? Anything else I should check out? Would a deteriorated vanos do this as well? She is I definite need of new vanos seals.

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First is run full diagnostics on it the dme and eml. It could just be a sensor. It sounds electrical. I have seen that too many times to count. It could be a cracked intake boot but the reason I say electrical is the fact that you shut it off and restart and it went away. That’s classic electronic symptoms of a failing component. But you need diagnostics run on it. It gets expensive and frustrating throwing parts at a car to try and fix it. Lots of mechanics are just parts changers. They keep replacing stuff until it’s fixed. Just spend time troubleshooting and the repair will go faster and cheaper.


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First is run full diagnostics on it the dme and eml. It could just be a sensor. It sounds electrical. I have seen that too many times to count. It could be a cracked intake boot but the reason I say electrical is the fact that you shut it off and restart and it went away. That’s classic electronic symptoms of a failing component. But you need diagnostics run on it. It gets expensive and frustrating throwing parts at a car to try and fix it. Lots of mechanics are just parts changers. They keep replacing stuff until it’s fixed. Just spend time troubleshooting and the repair will go faster and cheaper.


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Agreed. I'll hook up pa soft when I return home. Electrical could be fuel pump? When the EML light came on the car definitely felt like it wasn't running on all cylinders.

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Doubtful because when it goes to limp mode that’s just the way that they run. Like when a automatic transmission goes into limp mode it’s in 3rd gear for the entire time that you’re driving forward. It’s ok to get you home but I have had people that have been driving it in limp mode for a month and the transmission 3rd gear clutches are burnt up. But limp mode on the engine limit rpm fuel and cut timing so you experience a severe loss of power.


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Doubtful because when it goes to limp mode that’s just the way that they run. Like when a automatic transmission goes into limp mode it’s in 3rd gear for the entire time that you’re driving forward. It’s ok to get you home but I have had people that have been driving it in limp mode for a month and the transmission 3rd gear clutches are burnt up. But limp mode on the engine limit rpm fuel and cut timing so you experience a severe loss of power.


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Makes sense.

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Like when a automatic transmission goes into limp mode it’s in 3rd gear for the entire time that you’re driving forward.
I've never seen LIMP MODE in my E46 but my E34 was a different story. The first time it happened, turning the car OFF and ON solved it, for the moment. It happened again a few days later. After a prolonged search on the E34 board, it was suggested that I remove, clean and reinsert every fuse and relay in the under-hood fuse panel.

I owned that E34 another two years without ever seeing LIMP MODE again.
 

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Yes e34, e32 transmissions always had limp mode issues like your talking about. The car would have been to a dozen shops then we would get it and usually it was dirty electrical connections or low on transmission fluid. Because when they first eliminated dipsticks no one short of us locally knew how to properly top up a bmw auto transmission. That was decades ago. Man I’m getting old.


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Yes it’s the drive by wire throttle. Your gas pedal is basically a linear resistor and the throttle body has a small motor on it that moves the flap n the throttle body. Plus it’s a separate system from the dme.


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It could be your gas pedal. I remember reading a BMW TSB a few years back about the gas pedal in certain models and production date had a high failure rate of the pedals. If that happens to be the issue and you go used which is the way I always try to go. You need a pedal from a car with the same transmission. Manual pedal is different from the automatic.


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Discussion Starter #15
It could be your gas pedal. I remember reading a BMW TSB a few years back about the gas pedal in certain models and production date had a high failure rate of the pedals. If that happens to be the issue and you go used which is the way I always try to go. You need a pedal from a car with the same transmission. Manual pedal is different from the automatic.


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Funny you mention that...

Lately my guess pedal is squeaky as no other. What code or codes would put me into limp mode? Generally speaking...

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On it having codes that’s hard to say. Because little hiccups sometimes won’t store a code. But chances are good u will catch one


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The 2 most common failure points are the pedal and the throttle body. If one isn’t right neither will work right. It being squeaky makes me think that’s your problem.


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On it having codes that’s hard to say. Because little hiccups sometimes won’t store a code. But chances are good u will catch one


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Agreed. When my vw gti vr6s kps sensor went bad, it took me almost a month to finally store the code and know it was the crank sensor.

What are the likely culprits? Would o2 sensors do this? My experience In other cars says no...

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Discussion Starter #20
The 2 most common failure points are the pedal and the throttle body. If one isn’t right neither will work right. It being squeaky makes me think that’s your problem.


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How easy/difficult to replace the pedal?

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