[Kevin_S17]

I bought a 2.0T in July 2018. Approximately 1 month into ownership I notice what sounded like spark knock at RPMs above 5000. When the car shifted to a a higher gear it would stop but return at high rpm.

Car had good pull and no other remarkable issues. After a few weeks I attributed the sound to something loose under the hood. Possibly the cable that runs to the hood latch. After another month, I still would get spark knock (rattling) from under the hood but it seemed to be more random and happening at rpms below 5000.

3 days ago while driving around 60mph, the car backfired and lost power. Running extremely rough, service stabilitrak light and CEL. I was able to limp to the dealer approx 4 miles away at 30mph.

2 days ago the dealer called to say GM has instructed them to tear the motor down. The service rep said more than likely they would be replacing the motor. Anyone else had this issue?

I did have access to an OBD reader and it showed cylinder 1 was dead. Engine had 3800 miles.

[jaysonstuart]

I haven't, but I do know someone that has a 17' vert turbo 4 and she had her engine replaced due to some of the issues you are explaining. I saw her a few days ago and the car was back at the dealer for some more similar issues even after the engine replacement.



She's considering getting a lemon law buy back at this point.

[Elite Engineering]

LSPI, or Low Speed Pre Ignition. Common on all GDI engines, especially boosted ones. This occurs when am explosive mixture of fuel (as the fuel is introduced at 2,000-3,000 PSI directly into the cylinders) and oil vapors get behind the compression ring and ignite. The explosion is an erratic violent one and it breaks the piston at that ring land. It can be just breaking the land and it stays in place, or the entire side of that piston breaks off, and that is what occurs. Make SURE in the future to ONLY run one of the premium full synthetic oils that has the new formulation that renders these vapors less explosive. Our PCV crankcase evac system also prevents this by flushing and evacuating these vapors before they can build to the point of doing this. GM had an extremely high incidence of these failures with the Caddy ATS when it was first launched and instead of addressing the cause, made the pistons thicker in the area prone to failure. This has greatly reduced the incidence of failure, but it is still far to common. We do not recommend ever running a Synthetic blend, and many dealers even though they have been made aware of this still use the cheap syn blend for the "free" oil changes (you payed for in the price) to save$ and maximize profits.


Here are some pictures to show what occurs:


Severe:






Minor:






Questions? Just ask.

[Kevin_S17]

Originally Posted by Elite Engineering

LSPI, or Low Speed Pre Ignition. Common on all GDI engines, especially boosted ones. This occurs when am explosive mixture of fuel (as the fuel is introduced at 2,000-3,000 PSI directly into the cylinders) and oil vapors get behind the compression ring and ignite. The explosion is an erratic violent one and it breaks the piston at that ring land. It can be just breaking the land and it stays in place, or the entire side of that piston breaks off, and that is what occurs. Make SURE in the future to ONLY run one of the premium full synthetic oils that has the new formulation that renders these vapors less explosive.


Here are some pictures to show what occurs:


Severe:






Minor:

Based on the techs comments, I think my engine fell into the severe category. I knew I heard a bang. Just didn't realize it was my piston becoming shrapnel.

46 days later engine has been replaced.

[Elite Engineering]

That is correct Kevin S17. But you run the risk of a repeat as it is just what we covered in detail if the dealer uses the cheap synthetic blend oil!! They most likely will swear they don;t, but we still see many doing this on the "free" oil changes. Google search LSPI piston damage for anyone wanting to learn more. A GOOD full syn oil will have a new formulation that helps render the vapors less explosive. Amsoil pioneered this, but I believe Mobil one and other well known brands have followed suite.


Also, anyone else that has any doubt on what is occurring, pull off your intercooler and set it up right and watch the oil and other gunk drain out. And no, GM is well aware and no, they won't include a proper system on any production vehicles due to cost and lack of end users willing to drain them every few thousand miles.


And as always, ask questions on anything of a technical nature. Were happy to share and guide.


Cheers!!!