E39 535 missfire

I don't know if my problem was 'misfiring', but it was rough idling in
colder weather (say <5 deg C) when starting up cold. The dealer did some
reprogramming before the warranty ran out, now it is fine.

Still some times it rough idles.

Now, pure guess [don't know car mechnic lingo - just a combustion engineer]:
if you get <91 octane gas, engine management computer does something to
prevent spontaneous high compression ignition (knocking), since it is not
firing at the optimal timing, perhaps in colder weather (cold starts,
heaters, lights...) tends to load the alternator more, so you get rough
idle? The reprogramming is just a optimization for better engine computer
tuning for less grade of gas in your local climate?

Get better gas, and try again?

"pete" <peterturtill.DeleteThis@hotmail.com> wrote in message
news:7seno0hdd6ir9hhhi7976aeqdh3f2j8jom@4ax.com...
 > My motor was serviced just before I bought it a few weeks ago but I am
 > noticing it misfires when idling. Otherwise it performs OK and I am
 > happy with it but before I have the electrics stripped out I thought I
 > better check here to see if it is a common problem. It is a 1998 V8
 > 3.5 litre with 112k on the clock and a good history if anyone has any
 > ideas please.
 > smicker<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: E39 535 missfire 

"pete" <peterturtill.TakeThisOut@hotmail.com> a écrit dans le message de
news:7seno0hdd6ir9hhhi7976aeqdh3f2j8jom@4ax.com...
 > My motor was serviced just before I bought it a few weeks ago but I am
 > noticing it misfires when idling. Otherwise it performs OK and I am
 > happy with it but before I have the electrics stripped out I thought I
 > better check here to see if it is a common problem. It is a 1998 V8
 > 3.5 litre with 112k on the clock and a good history if anyone has any
 > ideas please.
 > smicker

I had a problem with the camshaft sensor, at about 150,000 kilometers, which
caused the engine to stall. It has been replaced and I haven't had an engine
running problem ever since.
Hope this helps.

--
Best regards.
Giovanni Tarantino
Bevaix (NE)
Switzerland
1997 Audi A4 2.8 Q 231,000 km (144,000 miles)
1997 BMW 535i 230,000 km (142,000 miles)<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: E39 535 missfire 

On Fri, 5 Nov 2004 14:50:40 -0500, "Fred W." <Fred.Wills@'remove this
to reply to' myrealbox.com> wrote:

 >
 >"pete" <peterturtill RemoveThis @hotmail.com> wrote in message
 >news:7seno0hdd6ir9hhhi7976aeqdh3f2j8jom@4ax.com...
  >> My motor was serviced just before I bought it a few weeks ago but I am
  >> noticing it misfires when idling. Otherwise it performs OK and I am
  >> happy with it but before I have the electrics stripped out I thought I
  >> better check here to see if it is a common problem. It is a 1998 V8
  >> 3.5 litre with 112k on the clock and a good history if anyone has any
  >> ideas please.
 >
 >Are you certain it is really misfiring? The V8 engines tend to "lope" a bit
 >at idle, even to the point where the car rocks a bit. I know mine does (94
 >540i alusil), but it then smooths right out as soon as you get off idle.

That is exactly what I am getting but it can only be caused by a
missfire surely?
pete<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: E39 535 missfire 

On Sat, 06 Nov 2004 17:22:15 GMT, "ppp-man" <dont.RemoveThis@bother.me> wrote:

 >Get better gas, and try again?

Just filled up with 97 octane and there is no difference:-(
pete<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: E39 535 missfire 

pete wrote:
 > On Fri, 5 Nov 2004 14:50:40 -0500, "Fred W." <Fred.Wills@'remove this
 > to reply to' myrealbox.com> wrote:
 >
 >
  >>"pete" <peterturtill.TakeThisOut@hotmail.com> wrote in message
  >>news:7seno0hdd6ir9hhhi7976aeqdh3f2j8jom@4ax.com...
  >>
   >>>My motor was serviced just before I bought it a few weeks ago but I am
   >>>noticing it misfires when idling. Otherwise it performs OK and I am
   >>>happy with it but before I have the electrics stripped out I thought I
   >>>better check here to see if it is a common problem. It is a 1998 V8
   >>>3.5 litre with 112k on the clock and a good history if anyone has any
   >>>ideas please.
  >>
  >>Are you certain it is really misfiring? The V8 engines tend to "lope" a bit
  >>at idle, even to the point where the car rocks a bit. I know mine does (94
  >>540i alusil), but it then smooths right out as soon as you get off idle.
 >
 >
 > That is exactly what I am getting but it can only be caused by a
 > missfire surely?
 > pete

No, unlike the inline sixes, it is normal for the V8 engines to lope
somewhat at idle speeds.

-Fred W<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: E39 535 missfire 

On Mon, 08 Nov 2004 09:24:40 -0500, Fred W
<Fred.Wills.TakeThisOut@SPAMmyrealbox.com> wrote:

 >pete wrote:
  >> On Fri, 5 Nov 2004 14:50:40 -0500, "Fred W." <Fred.Wills@'remove this
  >> to reply to' myrealbox.com> wrote:
  >>
  >>
   >>>"pete" <peterturtill.TakeThisOut@hotmail.com> wrote in message
   >>>news:7seno0hdd6ir9hhhi7976aeqdh3f2j8jom@4ax.com...
   >>>
   >>>>My motor was serviced just before I bought it a few weeks ago but I am
   >>>>noticing it misfires when idling. Otherwise it performs OK and I am
   >>>>happy with it but before I have the electrics stripped out I thought I
   >>>>better check here to see if it is a common problem. It is a 1998 V8
   >>>>3.5 litre with 112k on the clock and a good history if anyone has any
   >>>>ideas please.
   >>>
   >>>Are you certain it is really misfiring? The V8 engines tend to "lope" a bit
   >>>at idle, even to the point where the car rocks a bit. I know mine does (94
   >>>540i alusil), but it then smooths right out as soon as you get off idle.
  >>
  >>
  >> That is exactly what I am getting but it can only be caused by a
  >> missfire surely?
  >> pete
 >
 >No, unlike the inline sixes, it is normal for the V8 engines to lope
 >somewhat at idle speeds.

I am very relieved to hear that Fred but how does it happen? Is it
caused my the engine management system or is it an actual missfire?
Would the engine do this when brand new?
pete<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: E39 535 missfire 

On Fri, 05 Nov 2004 17:46:57 +0000, pete <peterturtill RemoveThis @hotmail.com>
wrote:

 >My motor was serviced just before I bought it a few weeks ago but I am
 >noticing it misfires when idling. Otherwise it performs OK and I am
 >happy with it but before I have the electrics stripped out I thought I
 >better check here to see if it is a common problem. It is a 1998 V8
 >3.5 litre with 112k on the clock and a good history if anyone has any
 >ideas please.

They put in new plugs, right? Well then, they set the gap to .028"
which is spec, and which is too small, especially for the Bosch
Platinum2. Pull the plugs and open the gap to .040" and your
roughness will vanish.


___

Please. No more Bushes.<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: E39 535 missfire 

On Tue, 09 Nov 2004 15:15:28 GMT, FoggyBottom <fogbottom.RemoveThis@nowhere.org>
wrote:

 >On Fri, 05 Nov 2004 17:46:57 +0000, pete <peterturtill.RemoveThis@hotmail.com>
 >wrote:
 >
  >>My motor was serviced just before I bought it a few weeks ago but I am
  >>noticing it misfires when idling. Otherwise it performs OK and I am
  >>happy with it but before I have the electrics stripped out I thought I
  >>better check here to see if it is a common problem. It is a 1998 V8
  >>3.5 litre with 112k on the clock and a good history if anyone has any
  >>ideas please.
 >
 >They put in new plugs, right? Well then, they set the gap to .028"
 >which is spec, and which is too small, especially for the Bosch
 >Platinum2. Pull the plugs and open the gap to .040" and your
 >roughness will vanish.

Great news. I thought there must be something wrong to cause it to
lope like it does on tick over.Thanks.
pete<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: E39 535 missfire