G20 Trans Slipping Nightmare: Help Needed

Hey! I had a similar issue with my 2001 Infiniti I30 last summer. Those symptoms sound exactly like what I experienced the grinding during shifts and that annoying whining noise were spot on. Turned out my torque converter was indeed failing. My old mechanic kept trying band-aid fixes, but I finally found a transmission specialist who diagnosed it properly. Had to replace the torque converter and also found some worn clutch plates while they were in there. It was pretty serious stuff had I kept driving it, could've ended up with complete transmission failure. Shop kept my car for 4 days, but they did great work. The transmission shifts smooth as butter now, no more whining or grinding. If I were you, I'd definitely get it checked out by a transmission specialist rather than a general mechanic. The symptoms you're describing aren't something you want to ignore. Been driving it trouble-free since then, about 15k km so far. Just make sure you find someone who really knows transmissions it makes all the difference.

Thanks for sharing your experience! That's really helpful to know. Glad you got it sorted out properly. By any chance, do you remember roughly how much the whole repair set you back? And has everything been running smoothly since then, or have you noticed any other issues pop up?

Hey again! Yeah, happy to share the details. The whole repair ended up costing me 2120€ to fix the automatic transmission converter turns out it was definitely that converter lockup clutch giving me grief. Since seeing that transmission specialist I mentioned, everything's been running like a dream. The grinding and whining completely disappeared after they fixed it. I know it wasn't cheap, but honestly, it was worth every penny to get it done right. My I30's been purring like a kitten since then no new issues at all. I'm actually really glad I went to a proper transmission specialist instead of trying to save money with quick fixes. Sometimes you just have to bite the bullet and get it done properly, you know? If you're experiencing similar issues with your G, I'd definitely recommend getting it checked out sooner rather than later. Those symptoms aren't going to fix themselves, and waiting too long could end up costing you even more in the long run. Trust me, the peace of mind knowing it's properly fixed is worth it!

thanks so much for all the details! I actually went ahead and took your advice about seeing a transmission specialist. Funny enough, my story turned out pretty similar to yours. Took it to this shop called Elite Transmissions yesterday they definitely knew their stuff! Just got the car back today, and they fixed the torque converter plus some worn-out parts. Set me back about 2300 €, but honestly, the difference is like night and day. No more weird grinding or that annoying whining noise. The shifts are super smooth now. Really appreciate you sharing your experience it gave me the push I needed to get it done properly instead of going for another quick fix. Sometimes you just need to hear from someone who's been through it, right? Anyway, thanks again for the help! Here's hoping both our Infinitis keep running smooth for a good long while.