Sudden Oil Loss. What's going on????

[timebak]

I have a 2021 Trail Boss LT with 6.2L and 10 speed tranny, bought new in Jan 21. It now has 39,164 miles. I always get oil changed on time and used Mobil 1 0W-20 Full Synthetic first few times and then couldn't get it for a while so changed to Valvoline 0W-20 Full Synthetic about 12,000 miles ago. The engine and drive train is totally stock.

Three weeks ago I had to go to Franklin, TN (175 miles, round trip) and, as usual before I go more than a few miles, I checked the oil, tire pressure, etc. Oil level was full, right at the top mark with oil warmed up. I went part of the way on the interstate, up and back, running about 80 mph. I've run to town and back a few times since then, making a total of about 325 miles since I last checked the oil level.

Tonight, coming home from town, the low oil level warning came on. I still had normal oil pressure, but I pulled over and checked the oil and it wasn't showing on the dipstick. I limped back to an O'Reilly's Auto Parts about 3/4 mile away, watching my oil pressure. Pressure never dropped below 30 psi on the gauge. Bought some more Valvoline. Took about 2 quarts to bring the oil level back up to the full mark.

How in the world can I lose 2 quarts of oil in only 325 miles in an engine this new (only 39,164 miles)????? I've never had to add oil to this engine, between changes, since it was brand new. What's going on???

Thanks in Advance,
Tim

 

[Jmzvet]

That much oil loss in so few miles is really odd unless its leaking or you have something seriously wrong internally. You should definitely be able to see a leak that large and notice drivability issues if you burnt 2 quarts in 325 miles.
I had a 2008 5.3 Suburban that would burn about 2 quarts every 5000mi and it drove fine. But not in 325 miles.

 

[timebak]

That much oil loss in so few miles is really odd unless its leaking or you have something seriously wrong internally. You should definitely be able to see a leak that large and notice drivability issues if you burnt 2 quarts in 325 miles.
I had a 2008 5.3 Suburban that would burn about 2 quarts every 5000mi and it drove fine. But not in 325 miles.

I agree totally. I've looked under it and, so far, haven't found any leak, but it was dark and all I had were a couple of flashlights to look with. I've seen some of the posts about the oil catch can but haven't seen any info on where the oil comes from that it's supposed to catch, that otherwise would be burned in the engine. Where does that oil come from, and what affects how much oil is sucked out of the engine and into the intake system, or the catch can, if one is installed????

 

[Grey]

I agree totally. I've looked under it and, so far, haven't found any leak, but it was dark and all I had were a couple of flashlights to look with. I've seen some of the posts about the oil catch can but haven't seen any info on where the oil comes from that it's supposed to catch, that otherwise would be burned in the engine. Where does that oil come from, and what affects how much oil is sucked out of the engine and into the intake system, or the catch can, if one is installed????

Catchcan oil is from positive crankcase pressure vent system. No way that is leaking that much oil in that short of time. It's a mix between vapors created by normal operating temp in an engine and the pressure created by the less than perfect seal in the combustion chamber with the pistons, just normal blow-by. IF, and this is a big if, this was an issue with the PCV system, then you would have noticed some pretty severe drivability issues with the amount of gunk that would be making its way into the top end. Even then I think you should be able to rule that out.

It HAS to be some sort of simple bottom end leak; bad filter gasket or drain plug. Even older engines that burn oil between changes burn it gradually, and it doesn't just START burning that much right away.

 

[scotman623]

I would definitely be calling the dealership under warranty if that continues to happen… Make sure to check around your oil filter, maybe a gasket leak? If not I would start to be concerned some..

 

[timebak]

Back in the day, the 70's, 80's and 90's, I built and/or modified a number of small and large block Chevy engines, small and large block Fords, and large block Chryslers, so I know quite a bit about engines. Had a friend that had a 63 Chevy with a 283 that was so loose that the pistons were swapping holes , and even it didn't burn oil that fast.

Since I topped it back up with oil last night, I've driven the truck about 80 miles, much at highway speeds of 60 to 75 mph. I made a point to park on new, clean, dry concrete at Church this morning. After Church, not a single drop of oil was on the concrete under the truck and not a drop was to be seen on the undercarriage. Can't really see the pan because of the skid plate, but there isn't any oil dripping off of it either. I checked the oil when I got home and it had sat for about 20 minutes. The oil level is actually a touch over full right now, so it apparently hasn't used anymore since last night.

I'll check the filter and drain plug anyway, even though if anything was loose, it sure didn't tighten itself enough to stop the leak. But, I WILL call the dealership in the morning.

 

[redman733]

This probably isn't you problem if you're not leaking any oil, but I'll mention it anyways.
Sometimes when removing a spin on filter the rubber seal will stick to the engine, and if you're not careful, you end up putting the new filter over the old seal and end up with 2 seals that leak all over.
Also, always remember to wipe some oil over the top of rubber seal on the new filter before installing to help this from happening to begin with.

 

[clstark7]

This probably isn't you problem if you're not leaking any oil, but I'll mention it anyways.
Sometimes when removing a spin on filter, the rubber seal will stick to the engine, and if you're not careful, you end up putting the new filter over the old seal and end up with 2 seals that leak all over.

My dad always warned me about this and pushed it in my head that I need to wipe clean that surface where the new gasket makes contact. That will help you feel if that old gasket is still stuck on there. The Fram filters were pretty popular back in the day for having those gaskets twist off and remain in place. So I quit using those a long time ago lol.

 

[clstark7]

I have a 2021 Trail Boss LT with 6.2L and 10 speed tranny, bought new in Jan 21. It now has 39,164 miles. I always get oil changed on time and used Mobil 1 0W-20 Full Synthetic first few times and then couldn't get it for a while so changed to Valvoline 0W-20 Full Synthetic about 12,000 miles ago. The engine and drive train is totally stock.

Three weeks ago I had to go to Franklin, TN (175 miles, round trip) and, as usual before I go more than a few miles, I checked the oil, tire pressure, etc. Oil level was full, right at the top mark with oil warmed up. I went part of the way on the interstate, up and back, running about 80 mph. I've run to town and back a few times since then, making a total of about 325 miles since I last checked the oil level.

Tonight, coming home from town, the low oil level warning came on. I still had normal oil pressure, but I pulled over and checked the oil and it wasn't showing on the dipstick. I limped back to an O'Reilly's Auto Parts about 3/4 mile away, watching my oil pressure. Pressure never dropped below 30 psi on the gauge. Bought some more Valvoline. Took about 2 quarts to bring the oil level back up to the full mark.

How in the world can I lose 2 quarts of oil in only 325 miles in an engine this new (only 39,164 miles)????? I've never had to add oil to this engine, between changes, since it was brand new. What's going on???

Thanks in Advance,
Tim

Did you do the oil change yourself, or have someone do it? I wonder if someone simply didn't add enough oil. I know a couple of generations ago, these Silverado's only took 6 quarts. I know that 8 quarts catches many people off guard, with this being a gas engine. That could possibly explain the difference.

 

[Gangly]

Its quite common to experience what you are experiencing, mainly because you aren't checking the engine oil correctly, or rather you arent checking it at the correct time. I made the same mistake and wound up over filling the engine so understand its not just you. The correct procedure requires that you wait 2 hours after the engine has been shut off to check the engine oil. If you cant wait 2 hours, then a bare minimum of 15 minutes for a warm engine, or 30 minutes if the engine is not warm. I checked mine immediately after stopping and I barely registered any oil on the dipstick so I quickly added enough to put me at the middle section of the oil fill range. I checked it again an hour later and the reading was WAAAAAAAY over the oil fill mark. Give the engine 15-20 minute to drain down and make sure you are on flat ground before you check it.

Per the Owners Manual:

 

[Gangly]

This probably isn't you problem if you're not leaking any oil, but I'll mention it anyways.
Sometimes when removing a spin on filter the rubber seal will stick to the engine, and if you're not careful, you end up putting the new filter over the old seal and end up with 2 seals that leak all over.
Also, always remember to wipe some oil over the top of rubber seal on the new filter before installing to help this from happening to begin with.

I've done the "double seal" thing before and its not pretty. Less than 2 seconds after tuning on the engine I blew oil all over the driveway and the underside of the truck. The funny thing was, the seal on the filter blew off and the other seal stayed attached to the block. You can actually see were my left foot was placed on the ground while I reached in to turn on the truck since its the only dry spot in the area.

 

[mrcolieman]

Oil in the coolant? I'm not real familiar with the oiling system of our V8s but a high pressure oil leak (above cooling system pressure) can give you oil in the coolant but no coolant in the oil... maybe worth a look. Good luck!

 

[Bandit]

I have a 2021 Trail Boss LT with 6.2L and 10 speed tranny, bought new in Jan 21. It now has 39,164 miles. I always get oil changed on time and used Mobil 1 0W-20 Full Synthetic first few times and then couldn't get it for a while so changed to Valvoline 0W-20 Full Synthetic about 12,000 miles ago. The engine and drive train is totally stock.

Three weeks ago I had to go to Franklin, TN (175 miles, round trip) and, as usual before I go more than a few miles, I checked the oil, tire pressure, etc. Oil level was full, right at the top mark with oil warmed up. I went part of the way on the interstate, up and back, running about 80 mph. I've run to town and back a few times since then, making a total of about 325 miles since I last checked the oil level.

Tonight, coming home from town, the low oil level warning came on. I still had normal oil pressure, but I pulled over and checked the oil and it wasn't showing on the dipstick. I limped back to an O'Reilly's Auto Parts about 3/4 mile away, watching my oil pressure. Pressure never dropped below 30 psi on the gauge. Bought some more Valvoline. Took about 2 quarts to bring the oil level back up to the full mark.

How in the world can I lose 2 quarts of oil in only 325 miles in an engine this new (only 39,164 miles)????? I've never had to add oil to this engine, between changes, since it was brand new. What's going on???

Thanks in Advance,
Tim

I know exactly what’s going on. I registered just to reply. Same thing they had a recall on several years ago on my 2012 equinox. They had a major recall on it and rebuilt engine with new pistons and rings since they were defective. There was zero leaking oil symptoms as it was all burning inside the engine. Oil would be full and fine and next time I checked it would be at least two quarts low in matter of a few months.

 

[Jmzvet]

That’s really odd since excessive oil consumption hasn’t been a known problem with the newer 5.3 / 6.2 engines.
My 2008 5.3 Suburban sucked about a quart every 5k miles but I haven’t seen that on my 2021 5.3.

 

[Ellis]

I had a 2011 GMC Sierra 5.3 that burned oil since day one. About one quart every thousand miles. I put oil in it until I got rid of it at 160,000 miles. I bought this truck new. Pulled a travel trailer all over the country, just carried oil with me. Hopefully my new TrailBoss will do better.