NHTSA opens preliminary probe into more than 870,000 GM vehicles

[jfoj]

15burban,

You seem to understand!

0W20 was due to the goverment bureaucrats, not someone designing engines for long term durability.

While racing applications may use lower weight oils, those engines are only required to last 500 miles or so. If the race teams can eek out a nano amount of horsepower with a lighter weight oil, who cares as long as the engine lasts the duration of the race. The engine will be disassembled and rebuilt or used at parts for other builds after each race. Race engines are also operated under pretty controlled situations as well. Pretty ideal operarting conditions.

My last oil anaylsis for oil what was run 2900 miles in my truck had a 1% fuel dilution. On the surface some may say that is more than acceptable. BUT, understand this was for only 2900 miles, assuming the same conditions at 6000 miles, the oil may have been at 2% fuel contamination. OK, maybe borderline concerning. But then understand my use of the vehicle is 80% highway, and by highway I mean when I start the engine, the trips will be 2-6 hours in length, non stop. Auto Stop/Start and DFM has been disabled.

What would the fuel dilution percentages be if I Remote Start and allow the engine to warm up for 15 minutes each time I drive the vehicle, what would the percentages be if I had the Auto Stop/Start enabled, drive 80% in stop and go traffic, and so forth? Even a 1% fuel dilution impacts the oil viscosity and can even cause the oil to be outside the expected viscosity range. At least starting with something a bit higher in viscosity, you may end up with a 20 weight oil by the time it is changed!

Folks should research API oil spec SN Plus, this is a newer standard that came about specifically because of fuel dilution and to again combat Low Speed Pre Ignition due to increased fuel dilution.

 

[DuraYuk]

15burban,

You seem to understand!

0W20 was due to the goverment bureaucrats, not someone designing engines for long term durability.

While racing applications may use lower weight oils, those engines are only required to last 500 miles or so. If the race teams can eek out a nano amount of horsepower with a lighter weight oil, who cares as long as the engine lasts the duration of the race. The engine will be disassembled and rebuilt or used at parts for other builds after each race. Race engines are also operated under pretty controlled situations as well. Pretty ideal operarting conditions.

My last oil anaylsis for oil what was run 2900 miles in my truck had a 1% fuel dilution. On the surface some may say that is more than acceptable. BUT, understand this was for only 2900 miles, assuming the same conditions at 6000 miles, the oil may have been at 2% fuel contamination. OK, maybe borderline concerning. But then understand my use of the vehicle is 80% highway, and by highway I mean when I start the engine, the trips will be 2-6 hours in length, non stop. Auto Stop/Start and DFM has been disabled.

What would the fuel dilution percentages be if I Remote Start and allow the engine to warm up for 15 minutes each time I drive the vehicle, what would the percentages be if I had the Auto Stop/Start enabled, drive 80% in stop and go traffic, and so forth? Even a 1% fuel dilution impacts the oil viscosity and can even cause the oil to be outside the expected viscosity range. At least starting with something a bit higher in viscosity, you may end up with a 20 weight oil by the time it is changed!

Folks should research API oil spec SN Plus, this is a newer standard that came about specifically because of fuel dilution and to again combat Low Speed Pre Ignition due to increased fuel dilution.

Omg. Lol. Not the gubment!

 

[KMeloney]

In my mind, if the failures are due to a bad run of parts, then a range of engines [with those parts] will likely fail. But if it's a design issue, then ALL of the 6.2s will fail, right?

 

[jfoj]

I think the 6.2l is a perfect storm of a number of issues. There were clearly some part problems, but these should have been flushed out a while ago. The lifter bore issue, assume this was resolved.

Some problems may be user induced by the way the vehicle is maintained and used. This includes everything from the fuel and oil used, how long between oil changes, if remote start is used often and allowing the engine to warm up at idle, Auto Stop/Start activity, DFM activity, heavy loading, towing, how much highway useage vs how in town useage.

Overall almost everything really leads to oil related problems no matter how you look at it. But the 6.2l also operates under very High Torque loading at low RPM's.

 

[Antonm]

Think that upping the oil thickness is a viable precaution to take? Think we should all be running higher-numbers oil in the 6.2?

100% YES, absolutely.

The short block and rotating assembly is identical, part number for part number, between the base Corvette 6.2 and the truck 6.2 ( camshaft has a different grind though). Guess what weight oil GM specs for that ,,, spoiler alert ,, it isn't 0W20.

Mobil 1 even came out with a GM dexos approved oil just for this, and its available at most regular autoparts stores.

Mobil 1 Full Synthetic Engine Oil 0W-40 1 Quart

Shop for Mobil 1 Full Synthetic Engine Oil 0W-40 1 Quart with confidence at AutoZone.com. Parts are just part of what we do. Get yours online today and pick up in store.

www.autozone.com

...

 

[Vladimir2306]

15burban,

You seem to understand!

0W20 was due to the goverment bureaucrats, not someone designing engines for long term durability.

While racing applications may use lower weight oils, those engines are only required to last 500 miles or so. If the race teams can eek out a nano amount of horsepower with a lighter weight oil, who cares as long as the engine lasts the duration of the race. The engine will be disassembled and rebuilt or used at parts for other builds after each race. Race engines are also operated under pretty controlled situations as well. Pretty ideal operarting conditions.

My last oil anaylsis for oil what was run 2900 miles in my truck had a 1% fuel dilution. On the surface some may say that is more than acceptable. BUT, understand this was for only 2900 miles, assuming the same conditions at 6000 miles, the oil may have been at 2% fuel contamination. OK, maybe borderline concerning. But then understand my use of the vehicle is 80% highway, and by highway I mean when I start the engine, the trips will be 2-6 hours in length, non stop. Auto Stop/Start and DFM has been disabled.

What would the fuel dilution percentages be if I Remote Start and allow the engine to warm up for 15 minutes each time I drive the vehicle, what would the percentages be if I had the Auto Stop/Start enabled, drive 80% in stop and go traffic, and so forth? Even a 1% fuel dilution impacts the oil viscosity and can even cause the oil to be outside the expected viscosity range. At least starting with something a bit higher in viscosity, you may end up with a 20 weight oil by the time it is changed!

Folks should research API oil spec SN Plus, this is a newer standard that came about specifically because of fuel dilution and to again combat Low Speed Pre Ignition due to increased fuel dilution.

I strongly disagree. 0w20 oil is excellent for urban operation and engine operation at low speeds. Here are engines that do not work in the 1000 rpm mode, but at 3000-4000 rpm, yes, they should be thicker. And our engines running at revs slightly above idle need liquid oil like a groove

 

[Vladimir2306]

100% YES, absolutely.

The short block and rotating assembly is identical, part number for part number, between the base Corvette 6.2 and the truck 6.2 ( camshaft has a different grind though). Guess what weight oil GM specs for that ,,, spoiler alert ,, it isn't 0W20.

Mobil 1 even came out with a GM dexos approved oil just for this, and its available at most regular autoparts stores.

Mobil 1 Full Synthetic Engine Oil 0W-40 1 Quart

Shop for Mobil 1 Full Synthetic Engine Oil 0W-40 1 Quart with confidence at AutoZone.com. Parts are just part of what we do. Get yours online today and pick up in store.

www.autozone.com

...

The corvette does not drive at low speeds, they cannot be compared

 

[Antonm]

While you may be on to something in these GM V8's, I personally own 2 Honda's (well, my grown daughters own them now), both with >150,000 miles on the clock, that are DFI, and have run 0W20 as specified by Honda since new. Daughter's fiance has a Prius (Toyota) with 195k, and it has run 0W16 it's whole life. So, to say "I would not run 0W20 or thinner engine oil in a modern engine" is too big a generalization, lots of modern vehicles with lots of miles running this stuff with high reliability. Yes, Honda had some early oil dilution issues in their DI+Turbo Earth Dreams, they corrected it. Mostly was symptoms of "making oil" but very few of them blew up.

Might it be wrong for these GM V8's...possibly, but I feel like there is a materials or design issue at play here bigger than the choice of oil.

I am looking forward to the results of the NHTSA's investigation. Perhaps then we will learn the true failure rate. I agree it is larger than GM has historically had...but they do build a large number of vehicles with this engine.

LOL, first your daughter is probably wearing the pants in the relationship if her fiancé is driving a Prius.

Second, yeah,, you do realize that Prius engine doesn't make anywhere near the torque of a 6.2 right. So its not trying to push the thin out out from between the bearings near as hard as the big V8.

Could the thin oil work in the big V8, yeap it sure could, if (and only if) you fed enough volume at sufficient pressure to the bearings, but the oil pump is something else they cut a bit on the 6.2. So the options are either replace the oil pump or run a thicker oil.
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[Antonm]

The corvette does not drive at low speeds, they cannot be compared

Really, that's funny right there.

Corvettes spend more time idling at cars and coffee than they doing driving. As awesome as they are the vast majority of Corvette owners are grandpas ,,,, that drive them like grandpas.
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[Antonm]

I strongly disagree. 0w20 oil is excellent for urban operation and engine operation at low speeds. Here are engines that do not work in the 1000 rpm mode, but at 3000-4000 rpm, yes, they should be thicker. And our engines running at revs slightly above idle need liquid oil like a groove

And you're seriously wrong too.

The 0W20 oil is inferior in every way other than a slight advantage in fuel economy to the 5W30 or 0W40 offerings from the same manufacturer.

The bearing clearances are not bigger in high torque turbo diesel applications, they all fall within the same thumb rule of about 0.001 inch of bearing clearance for every 1.0 inch of shaft diameter. Those slow, low revving (like the redline is 3K rpm) engines run a 15W40 oil, or sometimes in cold climates, a 5W40 oil. If what you said was true (which its not), then those engines would be running a thin oil too.
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