[bmw] 325e idle problems - UPDATE - Fixed!

[Thomas Bejma <tcbracing@xxxxxxxxxxx>]

First of all - thanks to the listers that responded to my issue regarding a
high idle (1200 RPM) on a '87 325e, the information was very h*lpful.  I'm
in the process of acquiring a Bentley manual as most of you advised.

Next, I'd like to explain what I did to fix the idle problem in the hopes
that I may h*lp someone else.

A lot of the advice regarding idle control said to clean the valve first.
They have a tendency to "carbon" up and stick.  The valve is right on the
top of the engine and very easy to get to so I started with this "free" fix.
Once removed, I sprayed Carb Cleaner into the openings and let it drain out.
There was some black liquid that came out so I knew it was doing something.
After, I sprayed some WD-40 into the openings to lubricate any of the moving
parts.

I re-installed the valve, started the car and waited for it to warm up.  As
soon as the temperature gage started to move (it was 17 deg F yesterday so
it took a while), the idle dropped below 1000 RPM and the engine began to
sputter.  Uh oh... Stall... Re-start, idle goes down to 500 RPM, sputter,
stall.  Uh oh...  Think, think, what did I do?  Hmmm (scratching head,
recalling other information on the web)...  Maybe vacuum leak?  Look under
hood... Hmmm, hoses look good, wait a minute, what's that...  Blending in
with the convoluted creases of the Air Intake Bellows (first large diameter
rubber elbow connected to the intake manifold) is a large gap?  Hmmm, looks
like electrical tape on the bellows.  Electrical tape seems to have
separated from rubber and is sucked into the 1/4" by 2" gap.  Nice repair
job (NOT!).  Get out 2 inch wide racer tape (colored duct tape - good for
200 mph, good for E30) and seal up bellows.  Start car, nice smooth idle
right at 800 RPM - Yea!!

Ordered new bellows from Bavarian ($19.95 - not bad).  Conclusion:  Looks
like the issue was a combination of the two problems (dirty idle control
valve and LARGE vacuum leak).

Also, for those concerned about the timing belt, fortunately all of the
service records were in the glove box (BONUS!) - Last timing belt 108k
miles, current mileage 136k - still have a little time, but it will be one
of the first spring/summer projects (along with the water pump).

Thanks again,
Tom
Harrison Twp, MI
1987 325e - idling smoothly
2002 Saturn VUE V6 AWD - good for the foot of snow last week
1969 Cutlass Convertible - restoration mode
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