1998 E39 Low Revs Rough - BMW Forum

AndyN · 10-16-2005, 03:27 PM

Hi all... just joined & first post - hoping you experts can help...

I've an E39 323SE manual 1998 just done 100,000 mls. Engine has suddenly lost power at low revs. almost miss firing as you accelerate, seems to pick up eventually but feels like a miss fire up through the revs. Also whilst cruising without warning the car suddenly feels like its lost all power for a second and then goes on o.k.

Only recent happening was when running low on fuel, computer said 29 miles left and I filled up - problem has appeared since then, so I wondered if the pump had picked up some muck along the way...

Any thoughts or ideas appreciated

Andy UK

dyami · 10-17-2005, 01:36 AM

what kind of fuel are you using? if its a low octane, usually it will spudder like that, or you will hear a hard knock in the engine. my old 88' 735 did the same thing....but i forgot what i did to it to fix it. it mainly did it in the morning when it was cold. i used to have a 84' honda accord that did almost the same thing. i changed both the fuel filters, ignition coil and the ignotion module and it ran like a top. try various things, or see what other people have to say

superdeadman · 10-17-2005, 10:00 AM

whats e39 323? e39 is 5-series...
but no idea here

AndyN · 10-17-2005, 02:29 PM

I wondered who would spot my deliberate mistake - Ha... I must have been stuck in a time warp from my last beemer which was a 323SE...

Anyway, thanks for the two responses, and I don't think it is fuel octane related, I'm begining to think that I did run the tank too empty and some muck has been drawn into the filter etc. Started o.k. this morning but as the day progressed a couple more total loss of power experiences, and erratic lumpy acceration. Sometimes it will run fine for miles and then....

Checked my bank balance and booked it into local UK dealers (Coopers Cobham) for this Wednesday -

Andy

superdeadman · 10-17-2005, 02:46 PM

hope they gonna find the problem..
personally i don't think its the fat that you almost ran out of gas... my car never has gas in it
EVER!
i had it to a point where it showed 1 mile ... hehehe
it's slow and such, but i didn't notice a decrease of power, and it does have 105000mi.

sp0rky · 10-17-2005, 02:54 PM

my e34 and e39 always display "- - -"
lol.

AndyN · 10-19-2005, 02:30 PM

Hi all - thought you might like to hear the outcome....

BMW dealer put the magic box on and diagnosed a faulty Crankhaft sensor. Replaced and now running well...

As suggested, I was way off the mark with my fuel thoughts..

Andy

da_bull · 10-20-2005, 06:21 AM

Quote:

Originally Posted by sp0rky

my e34 and e39 always display "- - -"
lol.

lol

dyami · 10-20-2005, 09:14 PM

how much was the sensor

AndyN · 10-23-2005, 03:39 PM

Diagnostics, sensor supplied & fitted £170 GBP - they did vallet the car as well!