asilverblazer

It would be coincidental for both front brake hoses or calipers to fail at the same time. There is an old thread on here of similar a similar issue, not sure how best to direct you to it - but I would be looking at the brake booster.

It could be consumption too, GM allows (acknowledges, expects?) some loss.

That's a bunch more variables, Grumpy might be able to calculate it, I'm not going to. Thanks for sharing, number 6 seems risky given the owner's manual statements:

I'm aware - but not to how much. Why I'm not alarmed at seeing 'fluctuations', 'drops', etc. on the dipstick... Is it in the range? Yes, good.

Again, every vehicle I've touched I drain out less than what I put in. (Further evidence is I use the new containers to take in the old oil, they never overflow, and there's plenty room to pour more in when the drain pan is empty. Usually, an empty quart bottle on the two newest trucks with room to spare in another.) Pull drain plug and let drain into catch pan. Pull filter and dump into catch pan, set upside down on the fancy little filter holder to drain 'more'. Take a few minutes to clean up, get new stuff out, etc. Clean drain plug, clean oil filter sealing surface, inspect things, whatever... Put drain plug in and install new filter. Fill engine with new oil set aside the new (empty) containers. Pour the old oil in the new containers, note the markings on the side, put old filter in the new filter box. Wipe out pan. Throw away one empty quart container. Cap the others, one will usually have some room in it still. There may be "some drop" on the dip stick, it's never been a quantity to warrant measuring for sake of comparing to any previous reading. Of course, given this conversation I'll be making much more careful observations of the reading on the dipstick, to see what 1 quart plus minus looks like within the marked area. However, the dipstick, in my opinion, isn't the most accurate gauge to determine "oil consumption, use, etc." not that I have any better alternative. I think it's best suited to determine if engine has a reasonable amount of oil to prevent failure. If an EXACT amount was required, it wouldn't have a range specified, it would have a single mark. GM knows some oil will be lost, note the acceptable consumption per mile. The larger capacity pans that have come about in the last decade I think are a result of that, to allow for some between changes without the result of oil starvation.

One could interpret this to mean the level should be right in the middle of the marked area, above the top line is indicated to be just as bad as below the bottom...

No, when I fill with new it's within the marked area on the stick, when I drain, it's still within the marked area. I've never measured where within the marked area it is at different times, if I were to estimate the differential between the highest and lowest point I'd guess less than 1/4".

I think this is the closest I'm going to get to reconciling your statements with my experience. Can you confirm you haven't measured the amount of oil drained from your engine to verify what quantity was in the engine at time of drain? For what its worth, the quote above EXACTLY replicates my observations on my 2015, 2016 and 2018, no measurable drop on the stick. EXCEPT that when I measure the oil volume drained from the pan - the drained volume is about a quart less compared to a new fill.

My question(s) are direct to this point, with no insult intended, could the dipstick not be showing an amount of loss comparable to what I see by measuring the volume drained at change time? I think most GM vehicles light comes on at max 7500 miles. I've also noted how much larger the oil pan capacity has grown - 10 quarts in my L5P, 9 in the Yukon, 10 in my previous Sierra. If 5 quarts in yesteryear could last 5k miles, the 10 should be doing 10k miles. That thought process isn't about oil life and degradation, but I'm alluding to maybe the capacity has grown to account for the 'loss' and prevent "seizing up all over the place" due to oil starvation.

My interest isn't what is or isn't oil use, I'm interested in your measuring the use (or lack of) to compare to my own experience/measurements.

To be clear I'm not arguing whether your vehicles do or do not use oil. I am interested in continuing a technical discussion about what amount, if any, we can measure as being 'used' or 'lost'. As I stated, I measure the oil volume that I have drained from the oil pan and compare that directly to how much I put back in. There is always more going in than what came out. Generally, at a minimum, 1-2 cups, at most 1-1.5 quarts. The smaller discrepancies, were smaller oil capacity engines (5 quart load) and the larger discrepancies were on larger oil capacity engines (9 quarts). Generally, these never showed any 'measurable' oil loss per the dipstick(s). Oil was always within the marked area. Could it have been higher in the marked area one time vs another, I have to assume so, but the level on the stick never warranted a more significant dipstick reading accuracy check. I've come to the conclusion that so long as the oil level is within the range on the dipstick the volume is acceptable. Any loss that doesn't exceed the published acceptable use or fall below the dipstick marking is not considered a problem, meaning, the amount that I see being lost are not 'abnormal' or enough to warrant further investigation. Could it be that your measurement method isn't accurate enough to show an amount of oil loss? (This isn't an insult; I am exploring the measurement limitations of dipstick readings.) To wit, an oil pan that spreads a large volume over a greater surface area compared to a narrower pan would show variations in their measured volume quite differently on a dipstick.

Give or take, all but my earliest vehicles had that short an interval. To be sure any vehicle I've touched this century, generally they've all been on a minimum 5k interval.

I haven't changed the oil on ANY vehicle in the last 30 years that had a full load of oil in the drain pan when it was changed. Any MAKE, MODEL, ENGINE, USE, TYPE, LOAD, TEMP, CAR, TRUCK, TRACTOR, ETC... never mattered. Generally, all are a quart short. I know 'some' will stay in the engine, some in the catch pan, etc. Never have ANY of them been close (say with in a cup) of being full. I know this because, I measure every waste oil volume and can compare it to refill volume. A 5 quart engine always has about 4 in the catch pan, every time.

The Falken AT3W has me intrigued, looks similar to the KO2 tread pattern.

Visual match isn't reliable, they might be the same externally but could have different internals. (Long ago, some traction adders have different requirements) Is there no longer a glove box sticker?

You can gain a little bit of height. Observe the clearance from the upper control arm to its droop limit tab on the frame. Less clearance, worse ride quality. Do not confuse the above with the space between jounce bumper (bump stop) and lower control arm. Generally, anything greater than 2" is too much and results in increased wear to ball joints specifically, but other parts too. An alignment will be required after adjusting.

I've seen them be a little off, never so much that they couldn't be mounted. The small amounts I've seen get taken up when tightened down. If that bushing is so tight that you can't spin it in the shock mounting tube to more closely align, then forcing it will be putting a bunch of extra torsional strain on the bushing that shouldn't be there and potentially cause the bushing to wear out faster. Yes, you can spin the bottom of the shock (180 degrees) independent of the spring and top mount, so long as you relieve the spring tension by breaking down the strut again. I think you already tried this and the result doesn't improve the situation. Given the above, Eibach should offer a reasonable resolution - if not, pick another brand.

Not sure what part you are referring to as "getting stuck" but if the blend door was getting stuck and finally gave up, that's where I would start. If it is a dual zone system, does either side get cold?

Same part = same warranty. If making the change to do so results in the cost skyrocketing it was a lousy part in the first place. I recently bought a temperature sensor for the Yukon. AC/Delco, GM $40 with a 2 year warranty Duralast $23 with a lifetime warranty Guess which one I bought. Squeezing out a customer today might save GM a little now, but no customers tomorrow will cost them more. They will eventually run out of 'loyal' customers to squeeze. Where are the new customers coming from anyways (another manufacturer they had a bad experience with)? A race to the bottom of who is the least awful to deal with.

They don't sound that awesome to me, replaced a bunch of parts that didn't fix the problem, meaning they didn't need replaced in the first place. All just to end up where GMC recommended originally. I'd be pretty irritated, wonder what the cost would have been for just the compressor. At least its fixed now.

gm - genius. The warranty on the part is based solely on who pays for it - when it is the EXACT SAME part. Let's make the warranty experience as awful as possible for our customers, that will build brand loyalty! Shareholder value today, no customers tomorrow, bankrupt next week.

Dealers are least knowledgeable about the warranty on their parts. Call any dealer and ask about the lifetime warranty on your Denali shocks. The level of ignorance and lies that will follow will amaze you. No wonder so many people HATE going to dealers. The dealer model is beyond dead - why any company (GM) would allow a third party between them and their customers is beyond baffling. Bad experience at the dealer = no GM products sold. This one part example above has convinced me I know more (or have access to the same information) than every GM dealer in the greater OKC metro area. They must be so used to talking to so many other ignorant consumers that I think even they begin to believe the absolute garbage they spout off.

Start with locating the crankshaft and camshaft position sensors (P0336 and P0011). Look for wiring damage, if it isn't a daily driver suspect rodent damage. Ignore the fuel trims and P0174 until the P0336 and P0011 are resolved. Given that there isn't a clear signal from the crankshaft and or cam shaft position, the truck likely doesn't know what to do with the VVT/cam shaft. I would first focus on the crankshaft position sensor, this might clean up the cam shaft position. Conversely, if the low oil pressure is indeed due to poor cam shaft bearings, those bearings might now be worn so much that they are allowing too much play causing the cam shaft position sensor to read all sorts of incorrect 'positions'. Otherwise, the oil pressure is not part of the problem at hand.

Wonder if the "full reset" without the sensor replacement would have fixed it. Curious to, if the sensor replacement required a vac and recharge of the refrigerant? Is this the high pressure switch, low pressure switch, or mysterious pressure sensor?

Too many variables, you'll never know what was actually wrong with it. What you spent money fixing that wasn't broken, you might fix the original problem and create a new one or worse, NOT fix the original problem, create a new and have multiple issues. This is the WORST strategy for fixing a problem. Work carefully and methodically, test each part carefully prior to replacing, like with the injector. You found the culprit, repaired, then, importantly, confirm the repair solved the problem. Adding another new part to the mix doesn't confirm the original problem has been resolved.