Hey guys, i’m located in Ft Lauderdale Fl and I’m running a ‘03 g35 coupe, pushing 180k right now, a thing of real beauty to me and I try my best to keep her in as good condition as possible. I needed a tranny change because the old one was knocking hard whenever I changed gears and also failed to engage reverse. The mech I worked with on it sourced a used tranny with low miles and installed it for me. When he did the test drive though, he realized the Valve Body was no good, because it wouldn’t go past gear 3. I’ve been in a bit of a bind lately since he returned the car to me. I’ve search around online and it seems this part is a rare commodity and when I do find one online, the costs vary from $1300 to $1500 and that doesn’t include it being programmed, but i’m a bit skeptic because whenever I call around to shops that can program it, they say it’s a risk that whichever one I buy might not work and I don’t wanna take that risk to pay for a new one only for it to not work. My question is, has anyone experienced this issue with their Valve body and can you offer any suggestions on a reasonably priced one between (maybe $500-$800) and any suggestions on where to go if you’re from Fl or just any advice in general with this situation? I’ve been driving for a few months now and it’s incredibly frustrating not being able to drive on the highways because I can’t go past 40mph and I feel like it I keep going it’s going to destroy the engine also.
I'm not completely sure what's going on here, you paid for a service and didn't receive the service but you were ok with paying for it because... why? Sounds like your mechanic doesn't actually know how to properly troubleshoot the issue and sold you something you might not have needed.
The valve body doesn't require programming, it's the TCM that needs the programming if it's brand new, if it was used then it doesn't. Also, your TCM is probably the external kind that's sitting right next to your ECM in the passenger footwell, not sure why your mechanic would want to replace it when it might not be the problem.
How exactly did your mechanic "realize the valve body is no good" other than a blind guess? Is the car throwing a transmission code?
Exactly what transmission did he put in there? Did he take a newer style RE5R05A with the internal TCM and swap your existing valve body into the donor transmission? Did he source an early model RE5 with the external TCM and swap it but it's still not shifting correctly?
At some point you might consider just going down to Nissan and paying for a 1 hour Consult-II diagnostic so they can run the self-diagnosis of the TCM to see what the actual problem is. Might just be a $20 solenoid on the valve body. Might be that your mechanic bent a pin on one of the transmission wiring harnesses. It's really hard to say at this point given the limited information you've provided.
EXACTLY what was the problem with the original tranny? I know you said "knocking hard and wouldn't go into reverse" but I'm not really sure what that means. Was the transmission light on? If so EXACTLY what error code was it throwing? If the light wasn't on then EXACTLY what was it doing in greater detail.
Thanks for the reply! So a little backstory, I'm not a gear head myself and I slowly started taking interest when I got this car about 3 years ago. The mechanic I mentioned is one whom I've known for almost 10 years now and he's always worked on my prev cars. He was always fair with me when it came to prices and I would do research and compare his prices from time to time in the early stages, then after a few years I just went with it because they weren't big deals. this was the first major car prob I've had.
Unfortunately I don't have the codes for the original tranny because that was a long time ago, but the exact probs were as follows:
1. cranking up was fine and moving from gear 1 to 2 was smooth, but then while transitioning to 3, there would be a delay for about 5secs and I could hear it trying to change with the rev meter going, up followed by a heavy slam/knock slightly pushing the car forward.
3 to 4 was a similar effect but less violent with the slam/knock and then 4 to 5 was smooth. the longer the journey from crank up, the smoother the shifting would get throughout the drive. it would take maybe about 20-30mins before the knocking subsided and the shifting was somewhat normal. I tried to mitigate this everyday by cranking up and leaving the car running for about 10-15mins (especially when I had company lol) to prevent the knocking for fear of more damage until I was able to pay to repair/replace it.
When it came to putting the car in reverse, it was a progressive decline, initially it would take a sec or two before It shifted, then over time it gradually increased in seconds before it shifted. After some months, it got to a point where it took upwards of 15secs to shift. Once I got frustrated and pressed the gas and it seemed liked It worked because the car would immediately engage and move, so then I started doing that to get it to move...but this was all AFTER the car was already driving throughout the trip, because i don't usually park facing in. If the car was cold, it would not for the life of me, go into reverse for a long time, I'm talking 10-15mins before it would get going.
the SES light was on of course and I remember some of the codes were related to the O2 sensors but, that tranny is gone so I can't go into details with the codes...it's been about 10months now and the only thing saving me is that I don't drive the car for more than a few days a week due to traveling for work, but now that's slowing down and I have to drive more, the search is intensified.
with regards to the replacement tranny I got now, this one was used with a little over 40k miles, and he just did a straight swap, no removing of parts from my old tranny. I wish I could tell you what style it was but I didn't get that info, it was literally just trust from the years of working with him that I went with when he said he found a replacement tranny. He's usually (emphasis on the usually) thorough with parts that he does in any car that he works on and I've never had an issue until this case. Also I need to mention that this was a two man job because he enlisted the help from another mechanic who was more verse in trannies to assist. He first experienced the problem when he took it for a test drive after replacing the tranny and said when the other mech took a look, he deduced it was the valve body was the issue. idk if they did an OBD scan or figured it out some other way, but when he told me and I did some Googling of the symptoms, they were a common recurrence on some sites. I'm going to do another OBD scan tomorrow to get the code(s) for this one. last time I did it, it was only one code that referenced the tranny.
The problem when I drive it is:
Cranks up fine and shifts cleanly up to gear 3, then I can feel It 'ghost shift' to 5 and still keep the same momentum like it was confused and trying to figure out how to shift. I don't know how to explain it in automatic mode, but when I use manual and shift past 3rd, the number changes but the rev meter keeps going up like it's still in 3rd and begging to shift up. so it can go up to gear 5 visually, but mechanically it's still in 3rd gear. also the SES light stays on the entire time.
additionally, another problem I forgot to mention that was with the old tranny and new, is what I saw online called a 'transmission slip'. The car would drive normal for a while (as normal as my tranny is anyway) and then whenever I stop, like at a light or anywhere in general, the car then 'seizes up' somehow and struggles to move off into gear. it feels as if the handbrake is on and the car is fighting to move off. it will continue to drive, but it doesn't sound like it's changing gear and the exhaust sounds louder while it struggles to move. Sometimes if I'm paying attention, whenever I slow down to almost a stop after a long drive without stopping, I can feel the car stutter and then the struggling happens. The only temporary remedy I found that resets this is whenever I shut the car off and restart it, then It drives like normal again, but whenever I do, the 'ATT CHECK' light blinks for a few secs then disappears.
I think that should cover everything, let me know if I missed any other questions
Ok those are some good details, next step is to get the car OBD2 scanned to pull all the codes it's throwing. Those codes basically tell you exactly what the computer sees the issue is, but they can require a bit of interpretation to know what's actually required to fix the problem.
Most of your auto parts houses like Napa, O'Reily, Autozone, etc will scan your car for free. Just make sure their scanner can handle engine and transmission codes (they typically do at parts houses, they want to sell you stuff).
ok, did an OBD scan at Advanced, this scan looks a bit different from the ones I usually do and so does the machine, but hopefully this will help. I'll try to go to another shop to get a scan from another machine to see if I can get a more straightforward scan with actual codes, but let me know if any of these make sense.
