I have an 03 GT with an idle speed that drops to 900 or 800 rpm (sometimes lower) when returning to idle.

After a short while it will sometimes creep up a bit to maybe 1,000rpm but increasingly will remain at the low idle speed.

A blip of the throttle sometimes coaxes it up.

I've noticed that if it's had a longer blast the idle does not drop as much, but this effect is short lived.

I've had an ECU change, initiated by this problem being reported to BMW about a year ago. Since then it had been well behaved before gradually exhibiting the same symptoms.

This coincided with a 12K service at which I had hoped it would disappear, but the symptoms are getting worse.

Now I'm out of my warranty, does anyone have suggestions for a remedy?

I don't know if there is any corolation but I was having the same symptoms. Since I have a Power Commander on my bike, the dealer said it was probably to blame.

Not too long after the low idle problem developed, my battery died. After replacing the battery, the low idle problem improved significantly. This happened at about 14,000 miles.

Since this occurred "at a 12K service", I would check for problems created by the service. UPDATE - I just reread your post and it indicates that it started around the time the 12K was due and you hoped that the 12K would fix it, so, this is probably of no use, but, since you are out-of-warranty, they are easy things to check (once the skins are off).

First, check all of the vacuum and vent lines and make sure that they are not pinched or that one came loose. Since they had to remove the tank to replace the air filter, there is a high possibility that they left a hose disconnected or pinched.

Some have noticed a major increase in gas tank pressure when the vent line to it was pinched.....try opening the fuel tank lid while it is idling bad and see if it affects your idle speed.

While you are under there, also check all of the electrical connections in this area. The fuel disconnects are idiot proof as far as putting them on wrong, but they are fragile if a tech puts any sideways pressure on them while disconnecting or re-connecting. Inspect these while the skins are off.

Other things to look at are pinched/binding throttle cables. One test is to engage your cruise control while going down the road. Does the bike surge up or down in speed a few miles per hour or is it a smooth operation? If it surges, check for binding and/or adjustment of the cruise control throttle cable (the one towards the rear of the bike). Both cables should operate freely and not stick.

I am assuming that it still starts and runs OK/normal since you didn't say that you were having other problems (hard/longer starts, stalls, missing, etc.). If you are having any of these (or other) problems, let us know since it may direct the trouble shooting elsewhere.

Good luck!

Randy

Thanks to htheater for the reply.

I have been putting off the moment of removing the plastic, but will do this over the next week and post again with results.

The bike runs well in all other repects, so was hoping that someone had some experience of the same problem and a possible cure.

BTW the problem wasn't caused by the service, just not fixed during it. Which means that it is probably something other than valves, plugs and the normal Moditec checks.