I could really use some help to figure out why a 2000 Toyota Avalon is having an intermittent shifting problem. I'm trying to repair it myself, due to it being a replacement for a 2004 Avalon, which was sadly recently totaled, about 2 months after dumping around $3k in repairs into it! So money is quite tight now. The 2000 has about 118k miles on it, still stock, and looks great. Clean engine bay, overall better looking than the '04. If only it ran as well as the '04 though. Here's the problem...
If you accelerate lightly, then the car runs fine, no shifting issues. However, sometimes when you accelerate moderately, or aggressively, it will either shudder, buck, or slam into gear. If I immediately let off of the gas, then give it gas, it shifts fine again. My guess would've been the torque converter going bad, but then I'm used to simpler cars and I'm not a mechanic. I see the shift solenoids can be a problem on these transmissions, but so far no codes for that.
The only code that was showing up, was for the front O2 sensor. No pending codes either. I replaced that sensor and now the engine runs smooth at idle. The engine seems to be running fine, it revs fine, no misfires reported either. I've swapped out the MAF and TPS, but neither had any effect on the shifting. All parts used are Toyota/Denso. I drained and filled the transmission fluid, which was pretty brown, but otherwise looked fine. No effect.
I'm at a loss at this point and am back to thinking it's a dreaded transmission problem, which I'm not equipped to repair myself. Or hey, if anyone knows one of those Witch Mountain alien kids that can undo car damage. 😆
Sorry for the loss of your ‘04.
Thanks avalon04. I've tried hard to turn the '00 into the '04, by swapping over a lot of parts, even the passenger door latch, for the open-while-locked feature. So the poor thing will live on to some extent.
Yeah I could just about bank. It's a transformation I had one did the same thing. I just sold it that was still going but it shift a little odd here and there. To actually fix it Cost a small fortune
Thanks Scotty, ugh, I was afraid of that. The car lot that sold it, supposedly wasn't even aware of the issue, but I was hoping it was just the common sensor(s) problem. Would have passed on it, but have to get the rental back and it was the best one I looked at. It's a shame the insurance has to take the '04, since I could just have the transmission swapped.
Yep you were right Scotty, although I'm surprised at the issue! A shop opened up the pan to find 2 bolts just laying in there, along with bits and chunks of metal! They want $3k to put in a used one, or $6k to rebuild it, yikes! Are prices really this crazy now? Last time I had a transmission rebuilt, it only cost half that. I should be getting pictures soon and we'll see what the car lot has to say. They have good reviews from folks, working with them when they found a serious problem, so I'm hoping they'll do the right thing with this very overpriced vehicle.
Can't catch a break lately though, sheesh!