What symptoms occur when you have a bad idle valve? Is the valve easy to change (DIY)? Is it pricy? Where is it's location on a "98 1.9 Z3. Read on another thread that this component was notoriously bad on earlier models of 1.9.
On my E30 the notorious sympton was a surging idle. I would assume a similar condition on your car even though yours is 9 years newer than mine. Simple to fix, but don't recall on pricing. They were pretty common for going out on E30's as well, so it wouldn't surprise me if your part was close kin to mine. Hope this helps, Alex
A surging idle or a constant high idle speed would be symptoms. Mine was the constant; revved at 3100rpm constant and made the car unbearable to drive. On the highway I could literally keep a constant speed in gear with no throttle because of it.
Try cleaning old one Before you purchase a new one, try removing your existing one and spraying it agressively with "carburetor cleaner". Sometimes its just that the valve gets dirty and goes not rotate smoothly. For my car, a good cleaning was all it took to return it to normal function (my symptoms were fluctuating idle when engine was cold). The Bentley manual describes how to test the electrical part of the valve as well as the mechanical part (basicaly just rotate the valve using an abrupt twisting motion and see if the valve opens and closes).
Many threads refer to the Bentley manual. Is it the best for those who attempt DIY?Where is the cheapest place to fine one. Does one edition superscede another? Sometimes there are older versions. Thanks, Ted PS: I don't have the symptoms described for a bad idle valve. If anything, my 1.9 idles a bit low.
The Bentley is the best manual. Its about $50 for the E36. Try ebay or online book sellers. Haynes is not bad and much cheaper. I have both and I have the Pelican Parts 101 Projects book which is cheap but project oriented.
I found my Haynes manual to be next to useless compared to the Bentley. The B is a lot more detailed and has a lot more content. It specifically outlines differences between models if there are discrepancies in the procedures for different models. My Haynes manual is half the size of the Bentley, AND it also includes 5 series information, which is useless to me as a 3 series owner. A five-minute search turned up these results: Amazon has it ($75.57): http://www.amazon.com/BMW-E36-Service-Manual-1996-2002/dp/0837612500 Tower Books ($75.47): http://www.tower.com/bmw-z3-robert-bentley-inc-paperback/wapi/107193157 eBay costs more than the rest, so I didn't bother linking. It seems that's as cheap as it's gonna get unless you can find one used somewhere...