clbdc@aol.com
01-01-2004, 05:11 PM
December 10, 2003
Here's a real life puzzler - and a challenge - about a year 2000 6 cylinder BMW 323 plain vanilla 4 door sedan, with automatic, that really has us troubled, not just puzzled, because of the quotes in the many hundreds (one over $1,000) we're getting from dealerships and independents to solve it.
Three clues to remember:
1 - the warmer the ambient temperature, the more often - and quicker - this will happen, and the longer it will take to self correct (everyone seems to translate this to: the engine has to cool down completely).
2 - the problem never occurs when the ambient temperature is in the low 30s or below.
3 - everyone thinks it is a sensor, but there's no agreement as to which one(s).
Cold engine (no matter what the ambient temperature). Engine starts perfectly. Car travels (at whatever speed), if temperature between 40 - 55 degrees for a longer distance (maybe a mile), whether stop-start or constant speed , and then stalls the first time thereafter but only when coming to a complete stop. Above 55 degrees, and especially when in the 70s or above, car goes only one, two city blocks, then stalls (but only at a complete stop, e.g. traffic light). In the high 30's the problem may appear after several miles - or not at all. And, if after starting, there's no stopping, like going right onto an interstate from the Motel 6 (remember, I said plain vanilla), no stalling until coming to a complete stop somewhere down the road.
After the first stall, engine will start, but it will stall once more, maybe twice, while trying to restart or moving off dead stop. But never three times. Thereafter, the engine will never stall, will always start easily - but the engine timing clearly is retarded, since below 3000 rpm (in "D" or in any "sportmatic" gear selected manually, even first), there's no "oomph".
Everything eventually self-corrects one of three ways. 1) Rarely, while driving along in, say high 30s or 40 degree temp and at a constant speed, the engine will suddenly develop more power all by itself (kindof like going from dim to bright) and up the revs (we think) by about 300-400. 2) Let the car sit overnight (no matter what the ambient temp). 3) (Most of the time but not always), let the car cool down when it's in the 40's outside, for about two-three hours.
Is it a sensor? Something else? Both?
Many thanks...
Here's a real life puzzler - and a challenge - about a year 2000 6 cylinder BMW 323 plain vanilla 4 door sedan, with automatic, that really has us troubled, not just puzzled, because of the quotes in the many hundreds (one over $1,000) we're getting from dealerships and independents to solve it.
Three clues to remember:
1 - the warmer the ambient temperature, the more often - and quicker - this will happen, and the longer it will take to self correct (everyone seems to translate this to: the engine has to cool down completely).
2 - the problem never occurs when the ambient temperature is in the low 30s or below.
3 - everyone thinks it is a sensor, but there's no agreement as to which one(s).
Cold engine (no matter what the ambient temperature). Engine starts perfectly. Car travels (at whatever speed), if temperature between 40 - 55 degrees for a longer distance (maybe a mile), whether stop-start or constant speed , and then stalls the first time thereafter but only when coming to a complete stop. Above 55 degrees, and especially when in the 70s or above, car goes only one, two city blocks, then stalls (but only at a complete stop, e.g. traffic light). In the high 30's the problem may appear after several miles - or not at all. And, if after starting, there's no stopping, like going right onto an interstate from the Motel 6 (remember, I said plain vanilla), no stalling until coming to a complete stop somewhere down the road.
After the first stall, engine will start, but it will stall once more, maybe twice, while trying to restart or moving off dead stop. But never three times. Thereafter, the engine will never stall, will always start easily - but the engine timing clearly is retarded, since below 3000 rpm (in "D" or in any "sportmatic" gear selected manually, even first), there's no "oomph".
Everything eventually self-corrects one of three ways. 1) Rarely, while driving along in, say high 30s or 40 degree temp and at a constant speed, the engine will suddenly develop more power all by itself (kindof like going from dim to bright) and up the revs (we think) by about 300-400. 2) Let the car sit overnight (no matter what the ambient temp). 3) (Most of the time but not always), let the car cool down when it's in the 40's outside, for about two-three hours.
Is it a sensor? Something else? Both?
Many thanks...