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

[PPK_]

Suggest you do your homework and research. LPSI is not just on forced induction small displacement engines. The 6.2 barely runs over 1800 RPM under all but sprited conditions and maybe towing where the engine downshift or if the shift points are altered much in other driving mode.

LSPI is more a function of oil introduced into the cylinders, liquid fuel in the cylinder and higher cylinder pressures during lower RPM, high load considtions where the throttle is open over 30-40%. Also understand the vehicle being propelled is not a 3000 lb rice rocket, this engine is propelling a 6000 brick.

Coupled with running Regular grade fuel. While the spec sheet for the L87 indicated it runs on Regular fuel, this is not what the owners manuals indicate. They recommend Premium fuel.

So.. 89 or higher octane? Catch can? 5w30 oil.. carbyte dfm tool.. is this it?

 

[jfoj]

So.. 89 or higher octane? Catch can? 5w30 oil.. carbyte dfm tool.. is this it?

I wish I had the magic ball. Hopefully GM knows exactly why the 6.2l are failing at the rate they are.

But my take after a lot of research about the problems, I took the following approach.

91-93 Octane fuel, take the possibility of LSPI out of the equation due fuel as much as possible, yes it costs more, but if it saves the engine and inconvienance of a failure, it is worth it.

5W30 oil all day long, 0W20 was not chosen for engine lifespan, it was to check some box to get closer to the CAFE ratings needed for the manufacturer. Continue to use a Dexos oil as part of the Dexos forumaltion is to reduce some detergants as these are contibutors to LPSI. 5W30 likely has less pumping use of oil if the DFM is fuctioning in any form and less cylinder face wash down due to DI, so again less oil in the combustion chamber and also less overall oil consumption. Very few oils other than 0W20 and 5W30 oil have Dexos ratings. Less oil in the combustion chamber and less the the usual detergents mean less possiblity of LSPI.

Catch can to reduce oil and moisture being pulled into the intake path for LSPI concerns as well as reducing intake valve carbon build up. Less oil in the combustion chamber, the less chance for LPSI. I believe that added moisture in the combustion chamber can also add up to more carbonizing of the oil around the piston ring grooves.

I am running the Range DFM disabler. While some say it does not fully disable DFM during Decel with Fuel Cut Off it is better than nothing. Additionally this also disabled the Auto Stop/Start feature as well. I think the Auto Stop/Start feature adds to dryer engine starts with 0W20 oil, 5w30 likely holds an oil film on the bearing surfaces longer and better than 0W20. Again, I also think there may be some pumping action that pulls oil past the piston rings when the DFM is enabled causing more oil consumption/oil in the cylinders. Not hearing about as many bent push rods or lifter failures on the newer year engines, so not sure these are as big of a problem these days, but more people are also probably running DFM disabler devices as well.

Added a magnetic drain plug, my 2005 6.0l had this as standard, while is may help things it is also a good indicator for me to see what iron and steel fines are in the crankcase. It may help reduce very fine iron and steel fines from getting past the filter, but who knows. more of a tool for me to judge what is going on inside the engine.

FilterMag, 2 half moon strong magnets that slip on the filter, yes stupid expense, but again may help with iron and steel fines and also allows me to see what is inside the filter when cut open.

Oil change, oil change, oil change. Changed at 500 miles, then at 3000 miles and will be changeing every 3000-4000 mile interval or about 50% on the OLM. Also running 9 qts with filter and prefilling oil filter before installation. Some may disagree, but this is what I am doing. Additonal 1 quart keeps oil level to where I found vehicle when delivered and allows for less impact on fuel dilution even with short interval oil changes.

Also performing oil anlysis on every change. More to track fuel contamination and potention early engine failure to maybe help determine if I get rid of vehicle before catastrophic failure?

Considering running Techron Fuel Additive every 2nd fill up as this has been suggested to help with ring groove carbon build up.

I may be over thinking and over doing things, but I really do not want an engine failure. The bulk of my driving once I start the engines is between 2-6 hours and usually highway driving. For example, I just returned home early this morning, 2:30 am after a 2 1/2 hour drive. Fine if the engine fails when the roads are lightly traveled hopefully I can get on the shoulder or somewhere safe, but not fine being stranded at 2:00 am where is it hard to see and to get someone to respond in BFE to tow my truck and then to get home at that hour.

We will see how things turn out, really only 2 possible outcomes.

1. My vehicle has an engine failure before 7,500 miles or somewhere between 25,000-35,000 miles,

2. I do not suffer an engine failure during my ownership of the vehicle.

I prefer what is behind door #2!

I am sure there may be some comments and other ideas.

 

[RG23RST]

Suggest you do your homework and research. LPSI is not just on forced induction small displacement engines. The 6.2 barely runs over 1800 RPM under all but sprited conditions and maybe towing where the engine downshift or if the shift points are altered much in other driving mode.

LSPI is more a function of oil introduced into the cylinders, liquid fuel in the cylinder and higher cylinder pressures during lower RPM, high load considtions where the throttle is open over 30-40%. Also understand the vehicle being propelled is not a 3000 lb rice rocket, this engine is propelling a 6000 brick.

Coupled with running Regular grade fuel. While the spec sheet for the L87 indicated it runs on Regular fuel, this is not what the owners manuals indicate. They recommend Premium fuel.

You may want to present these findings of yours to the two OEMs I've worked for. It would be news to them as it's counter to every bit of training I've had going back a decade. You can also admit you don't know what you're talking about.

Naturally aspirated engines do not have a high enough dynamic compression ratio to introduce LSPI. They also don't have charge air coolers pooling oil vapor and pulling it into the inlet manifold. LSPI got a lot of attention around a decade ago and then the problem was solved in short order. The fix was partly engine oil and partly controlling charge air temperature to keep the vapor and condensation from pooling.

 

[RG23RST]

So.. 89 or higher octane? Catch can? 5w30 oil.. carbyte dfm tool.. is this it?

You cannot out-maintenance defective bearings. That is the problem causing the catastrophic failure.

Lifter bore sizing, valve spring heat treat, etc were all separate issues that did not present as sudden engine failure.