[jeffk]

This morning I punched it hard to get on the freeway it took off fast like usual then it bogged down and RPMs surged up to 4000. Engine light can on blinking and my traction light came on. I aborted takeoff and pulled over on the shoulder. The idle was really rough. I powered off and back on and the light was solid idle still bad. My cheap scanner says P0300 P0301 P0171. I put it in D and accelerated and the light started blinking again. I parked and had it towed to the dealer. Dealer gave me a shuttle since they can't look at it until tomorrow. TELL ME THIS ISN'T A PISTON!

2018 Premier 2.0T 117000 miles

 

[campb292]

Sorry to read that. You did the right thing with the tow. Blinking light means don't drive.

It might be a piston. It might not to be a piston. The dealer will scan current codes then probably examine the spark plugs and do a compression and/or leak down test. Could be other things such as fuel injector, maybe a bad plug. I checked your post history and see a couple months ago you did a lot of maintenance including plugs. It could be a defective plug or maybe the wrong torque and it loosened. Let us know what happens.

 

[jeffk]

Dealer called and said the spark plug on cylinder one was smashed. The other 3 were fine. They replaced the plug under the plug warranty and are charging me $60 labor. It runs like new! I can't get there to pick it up until tomorrow morning.

 

[campb292]

Dealer called and said the spark plug on cylinder one was smashed. The other 3 were fine. They replaced the plug under the plug warranty and are charging me $60 labor. It runs like new! I can't get there to pick it up until tomorrow morning.

Smashed plug isn't very good. It could just be a defective plug or it was installed wrong.... maybe. There are several issues here and things I would want to know: 1) did the ground electrode stay attached to the plug or did it break off 2) what was the insulator condition 3) if the dealer has a guess as to how it happened.

My guess on a single smashed plug is pre-ignition. Could be totally fine now but knowing how these things go I have a bad feeling. You do you but if this were mine, I'd walk into that dealer at 9AM and try and trade it in without even getting in. Tell them it is in service for new plugs and have your eye on a new vehicle on the lot.

 

[DrivenDaily]

One without a turbo would be a wise move in my opinion.

 

[jeffk]

I picked it up. The warning lights are off. Idle seems higher but it could just be cold. Idle is still a little rough. They were really confident it would be fine now so if they are good i'm good. Thanks for the tips.

 

[jeffk]

I'm back at the dealer. As soon as I pulled out it was lurching and hesitating the lights came back on and it made a tacka tacka tacka tacka noise. They don't have a rental and shuttle is out running other people so I'm stuck here for now.

🤬

 

[jeffk]

The dealer called and said cylinder 1 is low pressure but they can't tell if it is a piston or a valve stuck open. He said it now has some misfire codes and codes for the catalyst and thats no good. They want $700 up front to take it apart but I probably need a new engine. I can't believe this happened. I got rid of my 2017 because I was so worried about the pistons then this engine blows up. What do I do? He said a new engine would be over $8000 and if its the piston 3 or 4 thousand and it'll never be the same. Couldn't this happen again if I put a new engine in? Are there junkyard engines? Should I keep it at the dealer or go to a shop? This really sucks. This is my 3rd GM car that had an engine just blow out. My 2003 Grand Am had a timing chain cause a ton of problems. My 2010 LTZ blew one of the head gaskets. Now this car eats a piston or a valve. This seems like strike 3 bad bad cars. Help please.

 

[JJA]

The dealer called and said cylinder 1 is low pressure but they can't tell if it is a piston or a valve stuck open. He said it now has some misfire codes and codes for the catalyst and thats no good. They want $700 up front to take it apart but I probably need a new engine. I can't believe this happened. I got rid of my 2017 because I was so worried about the pistons then this engine blows up. What do I do? He said a new engine would be over $8000 and if its the piston 3 or 4 thousand and it'll never be the same. Couldn't this happen again if I put a new engine in? Are there junkyard engines? Should I keep it at the dealer or go to a shop? This really sucks. This is my 3rd GM car that had an engine just blow out. My 2003 Grand Am had a timing chain cause a ton of problems. My 2010 LTZ blew one of the head gaskets. Now this car eats a piston or a valve. This seems like strike 3 bad bad cars. Help please.

Jeffk if you pay the $700 & it turns out it’s a valve rather than piston I assume that’s less expensive (?). If it turns out you need a new engine ($8k😩) I’d change oil more frequently cuz it looks like you do about 25k miles a year (?) BUT, you may decide it’s better to see what you can get out of it and find a reliable replacement-like a well maintained non-turbo. Sorry about this & I wish you the best

 

[jeffk]

My post was supposed to say piston or valve would be 3 or 4 thousand and the guy was pretty much leaning toward a piston because of the noise. I had them pause everything so I can gather info.

 

[jeffk]

Smashed plug isn't very good. It could just be a defective plug or it was installed wrong.... maybe. There are several issues here and things I would want to know: 1) did the ground electrode stay attached to the plug or did it break off 2) what was the insulator condition 3) if the dealer has a guess as to how it happened.

My guess on a single smashed plug is pre-ignition. Could be totally fine now but knowing how these things go I have a bad feeling. You do you but if this were mine, I'd walk into that dealer at 9AM and try and trade it in without even getting in. Tell them it is in service for new plugs and have your eye on a new vehicle on the lot.

I don't understand how you go from defective plug and could be totally fine to telling me to trade it in so I didn't take it seriously. Explain better next time.

 

[jeffk]

One without a turbo would be a wise move in my opinion.

Really helpful. I've had non-turbo cars crap out just the same it doesn't matter. Or what am I supposed to do by a fire hazard Bolt?

 

[campb292]

I don't understand how you go from defective plug and could be totally fine to telling me to trade it in so I didn't take it seriously. Explain better next time.

Really helpful. I've had non-turbo cars crap out just the same it doesn't matter. Or what am I supposed to do by a fire hazard Bolt?

Take a deep breath. I understand this is a stressful upsetting thing. It's not my fault, it's not @DrivenDaily's fault. My post yesterday was an attempt to acknowledge I am not there with your car so I can't make a certain diagnosis different than what you are being told by your dealer. You were told you had a smashed plug. I replied "could just be a defective plug... maybe". I told you the smashed plug isn't good. I offered my best guess cause: pre-ignition. It seems that is what happened. I then offered advice that seemed to be your best bet at protecting your car's value - immediate trade in while your service advisor was claiming the car "ran like new". You decided to drive it off the lot and here we are. That is also not entirely your fault. You expect professional work and were told everything is fine once the plug was replaced. You have every reason to trust your dealer over me (some guy on the internet). It turns out the guy on the internet was right, unfortunately.

I don't know what advice to give you at this point. I'm pretty sure they will find a cracked piston. I don't know if you pay the money for tear down if that comes off engine replacement cost (if necessary), if piston replacement is possible, I'm not sure if being at the dealer is the best value. I do know your current value likely exceeds the repair cost possibilities.

 

[DrivenDaily]

Really helpful. I've had non-turbo cars crap out just the same it doesn't matter. Or what am I supposed to do by a fire hazard Bolt?

As with the comments from @campb292, I feel bad for you.

I've never had a turbo, so I can't speak from experience with one. I've had engines die, most recently the 3.6L V6 in my current ride. It tossed one or two con rods at only 94,ooo miles. But it was covered under warranty, so that turned out good for me.

It would be nice if yours could have some kind of warranty coverage.

If you buy another used car, you're starting over at Square One, but you'll have a car that drives. However, you won't know if you can trust it or not until you drive it. The same goes with repairing this one, but the rest of the car is not unfamiliar, so that's a plus.

No matter what you decide, I hope it works out for you.

 

[cp-the-nerd]

Dealer called and said the spark plug on cylinder one was smashed. The other 3 were fine. They replaced the plug under the plug warranty and are charging me $60 labor. It runs like new! I can't get there to pick it up until tomorrow morning.

It is insane to me that this dealer was so inept. How could they possibly see that spark plug--knowing GM's recent ecotec turbo woes--and not even suspect the underlying problem? Test driving the car in that condition and then sending you home with it could have caused additional damage.

With used car values the way they are right now, I think the repair is probably worth the money. A similar replacement vehicle is going to run $20,000 or more.

 

[jeffk]

Take a deep breath. I understand this is a stressful upsetting thing. It's not my fault, it's not @DrivenDaily's fault. My post yesterday was an attempt to acknowledge I am not there with your car so I can't make a certain diagnosis different than what you are being told by your dealer. You were told you had a smashed plug. I replied "could just be a defective plug... maybe". I told you the smashed plug isn't good. I offered my best guess cause: pre-ignition. It seems that is what happened. I then offered advice that seemed to be your best bet at protecting your car's value - immediate trade in while your service advisor was claiming the car "ran like new". You decided to drive it off the lot and here we are. That is also not entirely your fault. You expect professional work and were told everything is fine once the plug was replaced. You have every reason to trust your dealer over me (some guy on the internet). It turns out the guy on the internet was right, unfortunately.

I don't know what advice to give you at this point. I'm pretty sure they will find a cracked piston. I don't know if you pay the money for tear down if that comes off engine replacement cost (if necessary), if piston replacement is possible, I'm not sure if being at the dealer is the best value. I do know your current value likely exceeds the repair cost possibilities.

As with the comments from @campb292, I feel bad for you.

I've never had a turbo, so I can't speak from experience with one. I've had engines die, most recently the 3.6L V6 in my current ride. It tossed one or two con rods at only 94,ooo miles. But it was covered under warranty, so that turned out good for me.

It would be nice if yours could have some kind of warranty coverage.

If you buy another used car, you're starting over at Square One, but you'll have a car that drives. However, you won't know if you can trust it or not until you drive it. The same goes with repairing this one, but the rest of the car is not unfamiliar, so that's a plus.

No matter what you decide, I hope it works out for you.

I need to apologize to you guys. I was irritated and venting. Everyone here has always been so helpful and there is no excuse for my words. After a couple days back and forth with GM my car has moved to engine replacement. They negotiated it down to five grand off of an estimate of eight. I had two pistons with cracks with 1 being much worse then 2. They said the wall in 1 was torn up. I have a loaner until next week. I have a question. Late last year I moved to doing oil changes by the monitor so around 7500. I had been doing changes between 4000 and 6000 miles. Could the longer interval have played a role? The tech I spoke with said ignore the oil monitor and change every 5. I have been using Pennzoil and Quaker State 5W30 both full synthetic.

 

[JJA]

I need to apologize to you guys. I was irritated and venting. Everyone here has always been so helpful and there is no excuse for my words. After a couple days back and forth with GM my car has moved to engine replacement. They negotiated it down to five grand off of an estimate of eight. I had two pistons with cracks with 1 being much worse then 2. They said the wall in 1 was torn up. I have a loaner until next week. I have a question. Late last year I moved to doing oil changes by the monitor so around 7500. I had been doing changes between 4000 and 6000 miles. Could the longer interval have played a role? The tech I spoke with said ignore the oil monitor and change every 5. I have been using Pennzoil and Quaker State 5W30 both full synthetic.

I hope you didn’t use Pennzoil Ultra Platinum-not Dexos approved due to high calcium content. (Pennzoil Platinum is Dexos approved oddly enough) Most would suggest changing @ 5k or so when it comes to these small turbo engines

 

[campb292]

Based on the values I see, the decision to move forward with the replacement is the best move. $5000 is still a lot but it's better than 8. You'll still hold your value and have a new engine. The transmission isn't a concern at all. I've started think of the 9T50 as tank status in these. There were a few solenoid issues early on but the software update largely fixed that. Let us know how it comes out.

Ditto on what @JJA wrote - if that oil was Ultra Platinum stay away. The regular Platinum Full synthetic is the way to go in that line. Just make sure you use dexos1 oil. I've been a 5000 interval guy for years now. I have no evidence that it fully protects your car. All I have is experience with mine rolling along at almost 140,000 miles with no piston issues, no PCV clogs, no leaks, no dry blown up vacuum pump.

 

[JJA]

Based on the values I see, the decision to move forward with the replacement is the best move. $5000 is still a lot but it's better than 8. You'll still hold your value and have a new engine. The transmission isn't a concern at all. I've started think of the 9T50 as tank status in these. There were a few solenoid issues early on but the software update largely fixed that. Let us know how it comes out. Ditto on what @JJA wrote - if that oil was Ultra Platinum stay away. The regular Platinum Full synthetic is the way to go in that line. Just make sure you use dexos1 oil. I've been a 5000 interval guy for years now. I have no evidence that it fully protects your car. All I have is experience with mine rolling along at almost 140,000 miles with no piston issues, no PCV clogs, no leaks, no dry blown up vacuum pump.

You get all the credit for the info Campb292, I just relayed what I learned 👍

 

[campb292]

Credit for what? Huh?

Edit: The Pennzoil Ultra Platinum thing I'm guessing haha 😂 That oil's trash!