Latest update. So after a few days of running the truck around town and highway, the transmission temps are now rising up to 232 without cooling down. Before the thermal bypass valve replacement, it would hit around 230F but not as often as I have seen it in the past few days. Even with the ambient temps being in the 60's. It seemed liked the issue with at least the high temp was resolved but I guess not. Owner's Manual states normal operating temperature is 180F-200F. I have had nothing but transmission issues and other parts going bad (gas pedal failure, condenser failure) for the past year of the two year period I have owned the car. I am starting the lemon law process. My time is short before my 24 month deadline is up for the reporting of the Lemon Law. I am not confident that years down the road there will not be a failure that's going to be really expensive.
Sorry for not updating sooner. Finally got the truck back on Tuesday after the dealership having it for almost a week and a half. So they had two master techs look at it during that time. One said the grit on the dipstick is rust from the dispstick tube itself and he then went to the lot and showed the same issue in other trucks to the second tech. The second tech said no, there's an issue as the fluid should not be that dark. Well finally they dropped the pan and found no shavings, transmission looks good, fluid was a bit dark. They decided to flush the fluid and then the second tech tested the transmission fluid thermal bypass valve and saw that it was failing. I had been commenting to the SA since I bought the truck that the transmission temp was getting up to 230F sometimes and he kept asking, are you getting an alert? I said no, then he said that's fine there is no issue. I would always tell him anything above 200F is going to cause fluid and transmission issues. Well they ended up replacing the thermal bypass valve and flush the fluid. I can now see the transmission temp gets to around 200F-203F and then starts to drop to around 194F-198F. Something I was not seeing before. This is the fourth time I had to bring it in for transmission issues. Not sure what to expect next.
Finally got a call from the service dept late yesterday afternoon right before closing. The SA tells me yes there is a problem and the master tech they used for transmissions was not able to get to my car to drop the pan and start to diagnose. This is one of two master technicians they have as the other was on vacation. They said they would get started on it today. They set me up with a blacked out 2020 GMC Yukon loaner this morning, which is a pretty nice ride. So now it's a waiting game to see what is actually wrong.
Just dropped it off. The same SA that told me last time the noise I was hearing was normal checked me in. I express my frustration and showed him the pictures. He has the nerve to tell me that the transmission fluid color will change over time. I said I understand but not at 11,000 miles after the last fluid change. The fluid smells and it had the debris in it. I showed him the pictures and he was like well yeah it should not be that dark. Duh!! So waiting to see what they find. If I don't like what they say, I will take it to another dealer.
Yep, I had already brought up my concerns with a weird sound when shifting into reverse gear a few weeks back when I took it in for the brake booster TSB. They said the checked the same function on another Sierra on the lot and it had the same noise. So I left it at that. Already made a follow up appt for Monday morning to bring it in for a look. What ticks me off is if I bring it in for a transmission concern, you would think they would at least check the fluid.
Hello all, I decided to check my transmission fluid today on my 2017 Sierra and when I pulled out the dip stick there was a dark sandy substance towards the bottom of the stick. I cleaned the dip stick, put back in and could notice that when I was sliding it back in I could hear it scrapping something grainy. I pulled the dip stick back out and check and still saw some of the sandy substance. The fluid did have a dark color to it. Keep in mind I just had the transmission repaired\rebuilt when the truck was under 10,000 miles. Supposedly a incorrect assembly at the factory. Now I am at 21,000 miles and seeing this has me concerned. See the pics below of the paper towel.
Did you have any check engine lights come on or just plugged in a code reader?
I have a 2017 Sierra 1500 that had already its transmission rebuilt around 12,000 miles. I’ve notice not too long after when stopping, then changing into reverse and pushing the gas, I hear almost like when you flick a aluminum can sound. The sounds comes from the middle of the truck under console. I also hear at times when slowing down from 3-2 gear. Any ideas If this is a transmission issue again? It’s heading to the dealer Wednesday. Right now it’s at 20,000 miles thanks
Is this sound different than the fuel pump? I hear what sounds like a sewing machine under acceleration under the drivers side floor.
I hit the P2127 twice in the past week on my Sierra. GMC Service diagnosed it to a low voltage issue with the pedal assembly and replaced it. I have had the Pedal Commander since December and I don't think this would have caused issue with the pedal assembly. I tried the re-seating of the Pedal Commander before taking it in but it just returned with the same error code. Of course I removed the Pedal commander once I hit this issue the second time and before I took it into service. Has anyone hit an issue with the Pedal commander causing the pedal assembly to fail?
JJCamper, I don't have a 4x4 but I do have a Sierra v6 that had similar issue. See here what the dealer found after I was told previously that it was normal operation. I also noticed it was worse when the transmission got up to temp. Oh, forgot to add hen shortly after the above work was done around 600 miles started doing the hard downshifts again and they found quote " Found several valves in the valve body scored due to metal in transmission at last repair of torque converter failure. This is causing valves to bind and stick intermittently when hot." They had to replace the upper and lower valve body assembly. You think they would have flushed the transmission after the first repair a few times.
Ordered my RidgeGrapplers from Tirebuyer the week of BlackFriday. Had them at my door in two days and had them mounted. The shop had a hard time road force balancing 3 tires. I called Tirebuyer up and they immediately shipped me 3 replacement tires. I completed the supporting paperwork and shipped the tires back to them with the provided return labels. Easiest transaction ever. The 3 new tires all road balanced with no issue.
I just did it again today. I happen to hop into the passenger seat today and turned on the ignition to refresh my SiriusXM radio. I then turned the car off and closed and lock the passenger door and the radio continued to play. Wasn't till I opened the drivers door and that it turned off.
Good Day all, I just did this mod and noticed that my radio stayed on after locking my doors. I also noticed the cargo light indicator on the switch was on as well. It wasn't until I opened and closed my drivers door that the radio shutoff. Any ideas?
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