cold start issue with Z3

Hi all. I have a '97 Z3 with the 2.8 I6. The car has about 131k miles on
it. Ever since colder weather has moved into my area (30s, 40s F), I've had
a problem when starting the car. It starts immediately and the idle jumps
above 1000 rpms. Then a few seconds later, the idle drops, the engine runs
real rough (like not all cylinders are firing), and it stalls. If I apply a
little gas to keep the rpms up after starting it, and then pull out of my
driveway, the engine still runs a little rough, but does not stall. Within
a couple of miles, the car is running great. My service manual indicates
that a faulty idle control valve could cause the engine to stop after the
initial startup, but doesn't say anything about it possibly being related to
the temperature, or if it could be a temporary problem. Is this the likely
culprit, or is there something else that could be affected by the
temperature and cause these symptoms? Any advise appreciated.

Thanks.

-=- Tom

Tom D > wrote:
>Hi all. I have a '97 Z3 with the 2.8 I6. The car has about 131k miles on
>it. Ever since colder weather has moved into my area (30s, 40s F), I've had
>a problem when starting the car. It starts immediately and the idle jumps
>above 1000 rpms. Then a few seconds later, the idle drops, the engine runs
>real rough (like not all cylinders are firing), and it stalls. If I apply a
>little gas to keep the rpms up after starting it, and then pull out of my
>driveway, the engine still runs a little rough, but does not stall. Within
>a couple of miles, the car is running great. My service manual indicates
>that a faulty idle control valve could cause the engine to stop after the
>initial startup, but doesn't say anything about it possibly being related to
>the temperature, or if it could be a temporary problem. Is this the likely
>culprit, or is there something else that could be affected by the
>temperature and cause these symptoms? Any advise appreciated.

The idle control valve is certainly the first thing I would worry about.
Clean the thing with a can of carb cleaner and make sure it moves freely.
While you have the carb cleaner out you might as well clean the throttle
body too; it's not the problem but it's something you ought to do now and
then.

Vacuum leaks can cause this sort of problem, too. If cleaning the idle
control valve doesn't do it, go in there with some propane or WD-40 and
see if you can find something sucking air in.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Hi Tom:

Your problem sounds like the well known VANOS seal failure problem
typical of the BMW inline six engine. Do a Goggle search on BMW VANOS
Failure and you should be able to find a web site with a name like
beasan or beasansys and they have a full explanation of the problem. I
have a Z3 too and had exactly the same problem. Replacing the VANOS
seals immediately stopped the problem. If you're a gearhead it is a
home project otherwise buy a rebuilt VANOS and have it installed by
your local independent BMW technician (or let him buy it). This is not
a repair for mechanics that do not understand BMW engines.

Good Luck.

RJD


On Sat, 5 Dec 2009 12:43:45 -0500, "Tom D" > wrote:

>Hi all. I have a '97 Z3 with the 2.8 I6. The car has about 131k miles on
>it. Ever since colder weather has moved into my area (30s, 40s F), I've had
>a problem when starting the car. It starts immediately and the idle jumps
>above 1000 rpms. Then a few seconds later, the idle drops, the engine runs
>real rough (like not all cylinders are firing), and it stalls. If I apply a
>little gas to keep the rpms up after starting it, and then pull out of my
>driveway, the engine still runs a little rough, but does not stall. Within
>a couple of miles, the car is running great. My service manual indicates
>that a faulty idle control valve could cause the engine to stop after the
>initial startup, but doesn't say anything about it possibly being related to
>the temperature, or if it could be a temporary problem. Is this the likely
>culprit, or is there something else that could be affected by the
>temperature and cause these symptoms? Any advise appreciated.
>
>Thanks.
>
>-=- Tom
>

"Tom D" > a écrit dans le message de news:
...
> Hi all. I have a '97 Z3 with the 2.8 I6. The car has about 131k miles on
> it. Ever since colder weather has moved into my area (30s, 40s F), I've
had
> a problem when starting the car. It starts immediately and the idle jumps
> above 1000 rpms. Then a few seconds later, the idle drops, the engine
runs
> real rough (like not all cylinders are firing), and it stalls. If I apply
a
> little gas to keep the rpms up after starting it, and then pull out of my
> driveway, the engine still runs a little rough, but does not stall.
Within
> a couple of miles, the car is running great. My service manual indicates
> that a faulty idle control valve could cause the engine to stop after the
> initial startup, but doesn't say anything about it possibly being related
to
> the temperature, or if it could be a temporary problem. Is this the
likely
> culprit, or is there something else that could be affected by the
> temperature and cause these symptoms? Any advise appreciated.
>
> Thanks.
>
> -=- Tom
>

I don't know if this will help but what I can say is that everytime I leave
my Z3 coupé 3 l in cold humidity for one night or even if I don't run the
engine until it's warm after washing, the day after I'll have rough idling
and missfiring until the engine is warm enough again. The problem seems to
comes from the ignition coils. BMW had issues with some manufacturers and
had a campaign to replace them. There possibly exists a technical bulletin
on the topis. Have a look.
Mine are genuine. The car has 135000 km on it. I began to have problems half
this mileage.
BTW, did you establish a relation with temperature, humidity, duration
between drives, ... ?

"RJD" > wrote in message
...
> Hi Tom:
>
> Your problem sounds like the well known VANOS seal failure problem
> typical of the BMW inline six engine. Do a Goggle search on BMW VANOS
> Failure and you should be able to find a web site with a name like
> beasan or beasansys and they have a full explanation of the problem. I
> have a Z3 too and had exactly the same problem. Replacing the VANOS
> seals immediately stopped the problem. If you're a gearhead it is a
> home project otherwise buy a rebuilt VANOS and have it installed by
> your local independent BMW technician (or let him buy it). This is not
> a repair for mechanics that do not understand BMW engines.
>
> Good Luck.
>
> RJD

My '99 328i has done this for years. Whenever the temp is below 45oF, the
idle becomes erratic when I stop for a light about 2 miles after a cold
start, occasionally stalling. As the car runs fine when warmed up, I
haven't worried about it.

(Another) Tom

On Sun, 6 Dec 2009 17:44:41 -0500, "tom_k" >
wrote:

>
>"RJD" > wrote in message
.. .
>> Hi Tom:
>>
>> Your problem sounds like the well known VANOS seal failure problem
>> typical of the BMW inline six engine. Do a Goggle search on BMW VANOS
>> Failure and you should be able to find a web site with a name like
>> beasan or beasansys and they have a full explanation of the problem. I
>> have a Z3 too and had exactly the same problem. Replacing the VANOS
>> seals immediately stopped the problem. If you're a gearhead it is a
>> home project otherwise buy a rebuilt VANOS and have it installed by
>> your local independent BMW technician (or let him buy it). This is not
>> a repair for mechanics that do not understand BMW engines.
>>
>> Good Luck.
>>
>> RJD
>
>My '99 328i has done this for years. Whenever the temp is below 45oF, the
>idle becomes erratic when I stop for a light about 2 miles after a cold
>start, occasionally stalling. As the car runs fine when warmed up, I
>haven't worried about it.
>
>(Another) Tom
>

Hi Tom:

If your situation is also VANOS related you lost low end torque and
about 2 miles per gallon. The reduced mileage was my first indication
as it seldom gets that cold where I live.

RJD

"Scott Dorsey" > wrote in message
...
> The idle control valve is certainly the first thing I would worry about.
> Clean the thing with a can of carb cleaner and make sure it moves freely.
> While you have the carb cleaner out you might as well clean the throttle
> body too; it's not the problem but it's something you ought to do now and
> then.
>
> Vacuum leaks can cause this sort of problem, too. If cleaning the idle
> control valve doesn't do it, go in there with some propane or WD-40 and
> see if you can find something sucking air in.
> --scott

Thanks for the suggestions. I'll give this a try and will see if it helps.

-=- Tom

"RJD" > wrote in message
...
> Hi Tom:
>
> Your problem sounds like the well known VANOS seal failure problem
> typical of the BMW inline six engine. Do a Goggle search on BMW VANOS
> Failure and you should be able to find a web site with a name like
> beasan or beasansys and they have a full explanation of the problem. I
> have a Z3 too and had exactly the same problem. Replacing the VANOS
> seals immediately stopped the problem. If you're a gearhead it is a
> home project otherwise buy a rebuilt VANOS and have it installed by
> your local independent BMW technician (or let him buy it). This is not
> a repair for mechanics that do not understand BMW engines.
>
> Good Luck.
>
> RJD

Thanks for the info. I found the page that you mentioned
(http://www.beisansystems.com/). It listed the cold start problem as an
issue with double vanos cars ('98-'00), so I may be OK in this regard since
mine is a '97. I'm not seeing any of the other symptoms shown on the site.
I looked through the steps for fixing this and it is beyond what I would
want to do on my own. I'll head to the shop to have this checked if nothing
else pans out.

-=- Tom

"frischmoutt" > wrote in message
...
> I don't know if this will help but what I can say is that everytime I
> leave
> my Z3 coupé 3 l in cold humidity for one night or even if I don't run the
> engine until it's warm after washing, the day after I'll have rough idling
> and missfiring until the engine is warm enough again. The problem seems to
> comes from the ignition coils. BMW had issues with some manufacturers and
> had a campaign to replace them. There possibly exists a technical bulletin
> on the topis. Have a look.
> Mine are genuine. The car has 135000 km on it. I began to have problems
> half
> this mileage.
> BTW, did you establish a relation with temperature, humidity, duration
> between drives, ... ?

Thanks for your comments. Basically, the problem has just started happening
with the cold weather. Doesn't matter if it is dry or humid. If I've been
driving the car and then park it, the longer it sits, the worse the problem
is. If it hasn't cooled down completely, it may run rough when started, but
it will be less likely to stall than when it sits overnight. Also forgot to
mention that I used a fault code reader and did not have any faults related
to the coils, or otherwise. But my service manual has procedures for
testing and inspecting them, so I'll put this on my list of things to do.

-=- Tom

"tom_k" > wrote in message
...
> My '99 328i has done this for years. Whenever the temp is below 45oF, the
> idle becomes erratic when I stop for a light about 2 miles after a cold
> start, occasionally stalling. As the car runs fine when warmed up, I
> haven't worried about it.
>
> (Another) Tom

Yeah, at this point it is more of an annoyance than anything. By the time I
get out of my driveway, it does not stall, and within a few miles it is
running fine.

-=- Tom