Hi, I'm new here! I have a quick question and I was wondering if you guys can help me out here. So I was driving my car down the road at approx 3k RPM. It ran completey fine until I hit a stop light. Then out of nowhere the engine started to idle really rough. The engine is so rough that it rocks the car side to side and I could feel a lot of vibration in the shifter. The check engine light comes on and I limped it home. Since this is a brand new car that I bought that same day with 60 brand new miles on it, I was really surprised. I checked the wires and everything seemd to be ok.

So I took it into the shop yesterday and the service manager gave me a call back and told me that the technician says that it seems like a broken valve spring. Mind you this is on a brand new engine off the dealers lot. He said that they found low compression in one of the cylinders and they pulled a bunch of misfiring codes. He said that they don't have valve springs on hand and will have to order them. So they don't really know when they will be finished with my car. How can they not have valve springs in stock?

The weird part is that I did not hear any clanking or banging at all. The engine actually sounded normal when i brought it up to 40mph on the way to the dealership. I thought it was just some electrical problems because the "Service stabilitrak" message came on. When the tech told me that he thinks it's the valve spring breaking, I was VERY surprised.


My biggest worry is that if it is indeed a valve dropping in the cylinder, I'm afraid that they will just replace the bare minimum and call it good. But if the valve scored up the cylinder walls, I'll never get good seal in that chamber ever again! Ugh...what do you guys think?

 

Similar situation to when I had a valve drop driving a friend's Corvette. It was about 300 miles after a cam/LS3 head swap on a LS2. Drove the car about 8 miles from home, with the last half being 75 mph on the freeway. Pull up to the light at the exit. Sit for about 20 seconds and then the engine starts running EXTREMELY rough and dies after about another 10 seconds. I could hear metal contact, so it was clear it was very bad. I tried to refire it, and got it to run again. It needed gas all the time to run at all, and metal on metal sound was still present. Blocked a major intersection for 10-15 mins and had a couple highway patrol cars join me for a while. Had it towed home from there. Three broken springs, one dropped valve. Fortunately it only did slight damage to the piston, so we could save everything but the valve and the springs.

In your situation, it's almost too bad you didn't really wreck the motor, since GM's footing the bill. Maybe the valve didn't actually drop totally free of the spring. If the valve was contacting the piston, in my experience, you'd hear it for sure. Out of curiosity, what kind of engine was this?

 

The tech will want to bill as much as possible, so he will bill as much as he can. I wouldn't worry about bare minimum

 

It's a LS3 engine in a 2011 Camaro.

I didn't hear any metal clunking at all. Just out of nowhere, it started to idle like crap. When I got it home, I turned it over for a few seconds and I could smell gas I so thought that it could have been an exhaust valve. But I was wishing that it was something minor because I just paid 36k for this car a few hours before it happened.

 

Good to know! I just hope it's true! I had the car for less than 24 hours and now it's back in the shop. I couldn't concentrate at work for the past few days hahaha.

 

My friend is a GM tech, and we bust his ***** all the time about it