QuestionQUESTION: I am about to turn this van in for a new vehicle. I have had a lot of problems with it. Right now the it is the power steering and Transmission. When on the highway for 15 min or more there is a loud noise especially when I turn the steering wheel left or right it will continue until I stop and turn off for a while. While driving on regular street at 40 to 50 miles no noise. My husband looked at the fluid at the time it was making the noise and it was bubbling. We are having the fluid flushed and replaced today.
Also just yesterday the engine light came on. It started shifting down at 25 miles an hour. My husband changed out the transmission fluid but it continues to shift down. He also changed the gas cap and the engine light went out. But it continues with the transmission problem.
ANSWER: Hi Diana,
Also check whether the belt that drives the power steering pump might be glazed and therefore slips when you make demands on it for energy, such as when you try turning. It may be the sound you hear is that of belt slip due to such a belt surface issue.
On the transmission I would go to a nationwide Autoparts store and and get a free code readout for finding out what the transmission computer has identified as to why it shifts down (do you mean to 2nd gear and won't shift up? which is called 'limp in mode which means the trans controller has observed a problem which needs attention and so shifts into the simplest mode which is 2nd gear). Let me know the code numbers. You might also use the ignition key:"on-off-on-off-on and leave on" doing that in 5 seconds or less elapsed time. Code will appear in the odometer window of the instrument cluster if any are stored in the engine or transmission computer. Let me know what you find.
Roland
PS Please 'rate' my answer, and where you see the question about a nomination to be "volunteer of the month" consider giving a 'yes' response.
Thank you
---------- FOLLOW-UP ----------
QUESTION: The power steering problem has been solved. It was flushed and the noise stopped.
We continue with the problem with the shifting down when speed changes to about 25 miles. I tried the ignition key procedure and it read donE. What does that mean?
AnswerHi Diana,
There are a number of possible causes for the harsh downshifting. Setting aside those that involve internal problems that would require removal and rebuilding, here are some simple things to check:
too low a level of fluid in the transmission (and resulting air bubbles in the fluid) for which he could check the fluid level via the dipstick but only use ATF +4 type fluid if some is needed.
the engine idle speed could be too low (it should be in the range of 700 to 800 rpm.
the oil filter in the transmission could be clogged or the internal pump pressure too low (that can be measured with a pressure gauge).
the valve body could be malfunctioning or leaking (that can be repaired without removing the transmission from the vehicle).
incorrect gearshift linkage adjustment, or possibly one of the engine mounts is fatigued such that the engine moves so much when slowing down that it inadvertantly shifts the gear of the transmission on its own.
Any thing else probably involves removal. So don't go that route until the above are eliminated.
Roland
PS Thanks for the rating and nomination.
Hi Diana,
The 'donE' means that the on-board fault code readout has found nothing to report. However it is possible that codes in the transmission controller have not been revealed. So as I suggested earlier do get a readout by means of code reader that plugs into a socket by the steering column under the dash. The Autozone store and similar nationwide parts stores will often to that free. Again, when you get the results let me know and also tell me what you mean by 'shifting down when the speed changes to about 25 mph' (does that mean as you are accelerating or decelerating, and does it seem to be shifting to 2nd gear)? A shift to second gear and refusing to leave that gear is called 'limp-in mode' and it is a defensive mechanism which protects the transmission when the trans controller thinks there is a problem. Also it means there is a code to be readout, hopefully by the plug-in reader, that says what the problem is.
Roland
