Quote:
Originally Posted by upallnight
Don't know if anyone corrected the comment by the original poster (didn't want to go through all the posts) that the car was brought to operating temp when he did the second fluid add with the engine running, but the fluid in the trans and when I say trans I also mean the torque converter should be in a range of 30C to 50C. Since our engine operates at close to 195F which is pretty close to the temp at which water boil 100C bringing the car to operating temp, exceeds the 50C range that the fluid should be at according to the procedure for checking and filling the trans.
|
That's an important point, because if you get the transmission too hot, the fluid with expand, causing it to spill out of the fill hole before the transmission is truly full.
To add more fuel to the fire surrounding the controversy about whether changing the trans fluid makes sense, I'd offer this - the average American keeps his car around 10 years now. This means there are probably tens, if not hundreds, of thousands of cars driving around with well over 150,000 miles on them. Of these, I'd say less than 20% have ever had their transmission fluid changed. If it were really that critical to do this, the roadsides would be strewn with cars with dead transmissions. I'm not saying this is a terrible thing to do, I'm just not convinced it really makes much difference, plus it's not exactly an inexpensive bit of maintenance.
As one anecdotal data point, I drained and filled the trans fluid on my daughter's 04 E46 about a year and a half, and 18,000 miles, ago. The fluid that came out looked brand new - not even a trace of sediment in the pan. It even smelled new. We have the records of the car since new, and there's no record of the trans fluid ever having been changed. It ran fine before, and it ran fine after the drain & fill. But now, 18 months later, it's starting to slip when cold. So, my conclusion is that the drain and fill didn't cause the current problem, but I don't think it did anything to delay it, either. In other words, I don't think it had any effect one way or the other. I think I'm going to pass on the drain & fill on our other two BMWs, including the X5.