Unregistered
05-30-2004, 12:02 AM
Hello all,
My 92 525i manual with 119K miles recently started to exhibit an idle surge problem after warming up. This problem may be recreated consistantly. I'm hoping to get some expert opinons on this problem before start replacing parts.
When the engine is cold, the idle is at about 650 rpm. Once the temperature gauge needle is beyond the blue marker, the engine would surge between 1400 and 1900rpm. After 5 minutes, the idle would jump up to 3000rpm and remains there, check engine light would come on. If I shut off the engine and restart, the check engine light is not on, but idle still surges bewteen 1600 and 1900, then jump to 3000. I unplugged the coolant temperature sensor from the engine block and the idle no longer surges, and idles constantly at about 650rpm but with sluggish pick up. However, the check engine light is on but the code reported is 1216, which is a bad throttle sensor, I expected the computer to report a bad coolant temperature sensor. Since I replaced the ICV about 9 months ago, I don't think that is the problem. By removing the temperature sensor, the computer thinks the engine is cold so I don't think the temperature sensor is bad but I might replace it anyway.
I couldn't find any related information in my Bently service manual so any thoughts will be greated appreciated. Thanks in advance!!!
Gary C.
My 92 525i manual with 119K miles recently started to exhibit an idle surge problem after warming up. This problem may be recreated consistantly. I'm hoping to get some expert opinons on this problem before start replacing parts.
When the engine is cold, the idle is at about 650 rpm. Once the temperature gauge needle is beyond the blue marker, the engine would surge between 1400 and 1900rpm. After 5 minutes, the idle would jump up to 3000rpm and remains there, check engine light would come on. If I shut off the engine and restart, the check engine light is not on, but idle still surges bewteen 1600 and 1900, then jump to 3000. I unplugged the coolant temperature sensor from the engine block and the idle no longer surges, and idles constantly at about 650rpm but with sluggish pick up. However, the check engine light is on but the code reported is 1216, which is a bad throttle sensor, I expected the computer to report a bad coolant temperature sensor. Since I replaced the ICV about 9 months ago, I don't think that is the problem. By removing the temperature sensor, the computer thinks the engine is cold so I don't think the temperature sensor is bad but I might replace it anyway.
I couldn't find any related information in my Bently service manual so any thoughts will be greated appreciated. Thanks in advance!!!
Gary C.