02 330ci Shudder while shifting through 1st and 2nd gear.....automatic

I cant feel it while im driving the car. I feel it while im in the passenger seat.
From take off i hit around 2000 rpm and feel this slight shudder. It happens again in second gear.....3rd 4th and 5th are fine.

One thing that has me concerned as well is the code telling me my transmission temperature sensor is malfunctioning. Not the one for the cooling system. This one is somewhere in the pan. When i checked my fluid last.....maybe 3 months ago it was very red as it had just been flushed in january. I can find nothing on this code.

I do also have low idle which i thought was cause by a vacuum leak. When i created a vacuum leak the idle went up so now i dont think thats causing the low idle. My idle is 550...it should be 700. Im wondering if this could cause this shudder somehow or am i looking at a transmission failure. The first time the fluid was changed was at 111,000.

For the shudder, it could be that the transmission is starting to go. But, you need to find out what that transmission code is, and what exactly it is indicating.

As for the low idle, when was your fuel filter changed last? If it was changed recently, how long was the previous filter on there? If the filter has not been changed, or if it was changed, but the previous one had high milage on it, then it could be your fuel pump. If the filter is old, or possibly original, then try changing it and your fuel pump. At best, this will fix the low idle issue. At worst, you should change your fuel pump and filter anyway, since there has been a huge number of fuel pumps dying recently. If yours is original, you need a new one anyway. The fuel pump may not fix the idle, but yours probably needs replaced, and this is as good a place as any to start addressing it. Do you have any codes that could be vacuum related?

But, I would sort out the transmission issue first, since it may be on its way out. There is no sense attacking the idle issue until you know what is wrong there.

Originally Posted by glhx

One thing that has me concerned as well is the code telling me my transmission temperature sensor is malfunctioning. Not the one for the cooling system. This one is somewhere in the pan. When i checked my fluid last.....maybe 3 months ago it was very red as it had just been flushed in january. I can find nothing on this code.

You mention it was "flushed", do you mean that a flushing machine was used on it, i.e. via the cooling line?

Fuel filter was changed 10,000 miles ago. Fuel pump has never been changed out. The car had 111,000 miles on it as far as i know before it had been changed. I would like to know the fuel pressure spec so i can check that.

How the fluid was flushed.......I did it myself......drained and then filled....ran through gears. did this over and over again until the fluid ran pure. I used 25 quarts to make sure this process removed all the old fluid. I then changed the filter and ran it through again. I am running valvoline max life. This was used base don research from someone on this forum...several people reALLY. the ran it 10,30 and 60,000 miles. They sent the fluid in to have it inspected for metal deposits and found that this fluid worked fine as the test results came back good. they posted the data sheets on the thread.

This is a picture of my code. Usually this is a red fault code and not a shadow code. the car had not been run in several days and the codes were cleared and rerun. The transmission was cool at the time... If i drove the car 25 miles and let the gears heat up. this would be a set fault code but would not throw a light.

with no loss of power.....could the fuel pump still be causing the low idle. I could see it doing that if there was some kind of fuel pump internal leak that is overcome by speed of the pump and an increase in pressure.