lundimpact1775

Just swap the trans thermostat. It's totally separate and unrelated to the engine thermostat. My engine runs exactly as it was intended, my trans runs cooler by my choice. 6L80 and 6L890 prior to my2014 never had a tstat on the trans fluid and ran full cooling always.

Man that sucks. I replaced the whole wheel in my 2020 for this reason, plus the wheel itself was peeling/ crumbling. I can tell the brand new one is going to do it soon too. Piece of garbage

Popped at 92k miles. Better than the diesel flavor of this problem, but still cost me 3k in parts and labor. Took out the injectors with the forbidden glitter.

1) GM flex fuel sensor (would be factory on a flex capable truck) 2) wideband map sensor, I believe. My tuner added this as part of their package. He's well known, twin cities performance is the name of the shop. Located in Saint Paul 3) ECM had to be bench unlocked at HP tuners. Apparently it's the only way to get into global B platform. 4) the actual tuning. I opted for a street tuned rather than Dyno, since it's not a race car and I didn't want to buy an aftermarket drive shaft. Stock L8T with 6l90 and 89k miles ran 0-60 in about 9.5 seconds. I'm getting 6.5 seconds running on e85 now. We set up the tables to run e85 or 91, since 91 is prevalent around here. I've considered re-tuning for e85 and 87, but I do like the benefit of no or very little KR. I run 91 in the winter to avoid excessive cranking times. Mpg's about 30% Lower on corn, as one would mathematically expect. Interestingly, mpg's while towing on e85 are actually not as far off as the 91. To answer the other question above, I had some real bad luck with my hpfp and the OEM replacement that went in after the first one failed. Trans cooler seems to get plugged up with leaves and debris more than any other vehicle I've ever owned. It's noisy which I've observed with other using l8t's but not all of them. The noises seem to vary quite a bit from one unit to the next. Also some battery issues, and interior quality is very sub par. It's still a fun truck after the tune. It pulls whatever I care to connect to it, and interior space is outstanding for my growing family.

Bring it to a reputable tuner and have them do the e85 conversion. Despite the other issues I e had related to GM quality, the L8T is very fun to drive on corn gas and with a proper ECM and TCM tune. Twin cities performance (CJTunes) did mine. It keeps me happy with an otherwise problematic vehicle. Smiles per gallon are unmeasurable

When my hpfp popped it exhibited the same symptoms. Died, started again extremely rough, every dash light was on and multiple codes. Observing the codes the two that stood out to me were both related to fuel system pressure. I noted this and discussed with the shop that I had it towed to. They confirmed my roadside diagnosis was correct- hpfp failure. The fun really got extra fun when it happened again 3 days after it was replaced. Electrical failure the 2nd time due to faulty part from GM, as opposed to the original catastrophic mechanical failure. Anyway, something to consider. Take all those codes and see if 2-3 of them are related to fuel system pressure.

Did you figure this out, and do you have audio from outside the truck? Mine sounds similar but can't hear it in the truck only outside or with the windows down.

P0446 looks like possibly fuel tank pressure sensor. Assuming all else in the evap system functions properly, a malfunctioning ftp sensor seems to often be the culprit per some quick research through these forums. Seems fairly common on multiple generations of Silverado. No idea how to replace on these new models you'd have to do more research on that.

I mean, I see that listed online but also have the paperwork showing GM just paid for this work on mine.

GM decided to cover my oil lines in full. 99,200 miles just fyi in case anyone needs them replaced be sure to press for that 100k power train warranty. Oil lines and associated hardware and labor are listed as covered.

Fuel acts as coolant to keep the pump from burning up, as I understand it. They say those who run tanks empty all the time burn pumps faster, but I have no data to back that up just info from old mechanics who have been there many times. I cut an access hole in my old 1997, never caused any problems or premature rust even up here in MN and WI, and was much simpler than box removal or tank drop. If I had to do it with a newer truck I'd probably just drop the tank but it depends, my 2500 has a 36 gallon tank and if it failed while full I know it's a total nightmare to try to empty these without just consuming the fuel.

I'm interested in this, been doing some reading. I'll probably plan something out and proactively replace before they fail again. But it's getting new lines now so I should be good for 40-50k more, right? Right?!

Confirmed, oil cooler line went to hell, that explains my recent excessive "consumption". This has brought me a sigh of relief. I'm no stranger to oil lines wearing out, same happened on my 1997, 2010, and 2016. Wish they were a better design but at the end of the day it's not a huge ordeal.

Yeah I phrased that poorly my bad. I have zero interest in paying the market price for new pickup trucks today. In other news after topping off my oil my truck's been sitting here a few days and I have an oil drip somewhere. Looks like possibly oil cooler lines but I'm on the road right now so I'll have to check when I get home. Maybe I'm not burning oil and it's just a typical 100K wear item. I'd actually be a lot happier if this were the case.

Oh I hear you. Found one with good maintenance records and prices correctly. Zero interest here paying more than 40k for a used truck and nearly 60 for a new one so my options get rather limited. Just going to live with this "in spec" consumption for now, hopefully an alternate oil will solve it. If not, I guess it's back to shopping.