Cadillac CTS First Generation Forum - 2003 - 2007 Discussion, 2003 CTS shifts really hard at times in Cadillac CTS Coupe, Sport Sedan and Sport Wagon Forums; Hi everyone, been on here a while, but haven't made any posts for some reason lol.
My friends 2003 CTS ...
Hi everyone, been on here a while, but haven't made any posts for some reason lol.
My friends 2003 CTS with the lovely 3.2L engine shifts hard once in a while. She said it shifts hard when downshifting also. I haven't been in the car when this happens, but she says none of the warning lights like decreased performance or check engine are lit. To me it sounds like an IAT sensor or such throwing the transmission into limp mode. On the phone I had her pull over, turn off the car and put the car in reverse and D4 as it has the rattling shifter from the genius plastic bushing linkage design, but that did nothing. I also had her try opening and closing the driver side door as that resets things on some wacky car designs. After she got to where she was going and was there for about 30 minutes, she left there with no shifting problems.
A couple days before this occurred I did change the passenger side catalytic converter as she's had code P0420 and cleaned the PCV vent pipe and drilled the holes larger. The day after this happened I replaced the crank position sensor as the car stalled out on her and wouldn't start till 10 minutes later. I also tightened the E8 bolt for the oil filter housing cause there was a decent leak there.
The car hasn't stalled or shifted hard since all this work, but she hasn't driven it much and I wouldn't think they would be the cause of hard shifting. I hope she can get a 2005 or newer CTS cause this car is a pain , but till then I'm the one fixing it. Any thoughts of what would do this?
Try cleaning the throttle body and check its connector
Sorry forgot to mention while cleaning the PCV pipes I cleaned the throttle body contacts under the cover that you have to remove the 6 clips to access and the electric plug connection with electronic connection cleaner. Do you think that will keep it from reoccurring or is there other known things that will cause the hard shifting? So far it hasn't done it again so I'm keeping my fingers crossed.
We port the TB's and don't take them apart.....hard to not screw them up due to the design if you do. It may be it if it started at the same time.
Throttle body hasn't been ported nor has the rest of the car modified. The plate was a bit dirty about a month ago so it was cleaned. I just cleaned the electrical part of it the other day after she complained about the hard shifts. Weird thing I did notice the throttle body making clicking sounds for about a minute after the car was turned off and the key out of the ignition. That was before the electrical contacts cleaning also.