DavePowell

My 2014 with 15,000 miles broke a valve spring last week, and the dealership told me that it isn't unusual, and fixed it in two days. Anyone else had that?

I pulled out on a street in town (rush hour) and it missed badly, then quit. I tried several times to restart and it would fire a few times and not catch. I asked how the tech how one valve would keep it from starting and the tech told me it was in "limp home" mode. I didn't have time to ask more.

I'd experienced "limp home" when the Vitesse (connected to the throttle) failed on the interstate and I could do only about 50 mph on level road. This time wasn't like that since I couldn't limp anywhere. Anyone know why the whole engine would shut down for one valve?

It reminded me of when I was going to school last century, 40 miles from my home. I had put a 283 in the Chevy and halfway to school it began to knock loudly. I made it. I pulled the pan in the parking lot. One rod moved 1/8" when touched since the rod bearing had spun, taking the crankshaft journal.

So, I drove some copper tubing into the crank's oil hole, removed the piston and rod, reassembled it and drove it back home with the piston and rod in the back floor. It was smooth but of course had a bit less power.

From this memory, I was surprised that the recent failure would kill the engine.

Dave

05XLRtoC7_San Diego

Sorry to hear this happened.
I wonder what the dealership would have charged once out of warranty?

DavePowell

I've also wondered that, but since it's drivetrain, I have until February 2019.

Dave

robertbruce

That 283 motor was the toughest motor Chevy ever made.

05XLRtoC7_San Diego

I was planning to keep my C7 for maybe 10 years.
Maybe not if this starts happening to a lot of cars

fpcopo

How did you get the piston out? You would have had to remove the head also.

DavePowell

Yep.

After I'd finished reassembling it I told a friend and started it to show him it would run. It was winter and I hadn't thought of removing the plug wire. I pumped the gas to start the 7-cylinder engine as he was watching with the hood open. When it started, the spark ignited the fuel vapors in the crankcase. The oil fill cap blew off and ricocheted against the open hood. It made quite an impression on him (not literally since it didn't hit him).

Dave

roadbike56

Might want to think about an extended GMEPP warranty if yours has not run out. If I recall correctly, mine runs out in 2022.
As for broken valve springs on the LT, there have been other posts here about the LT1 having this issue so I'm thinking my 2014 might have to deal with this.
Nothing new here, my 69 lunched two of them. The first was replaced under warranty. When the second occurred I replaced all 16.

JerryU

Ah yes, those were the days! Great way to get it back home! There was even room to get a pan out "in the day!" Recall doing similar things with bailing wire! You did what you had to do! Something to remeber the rest of your life.

Today the computer monitors everything! It monitors the rotational movement of the crank with each cylinder firing. If one misses a few times it also shuts things down and will probably go to limp home mode!

Even measures the current flowing in a wire! If it's a higher amount than it's supposed to be it may trip a breaker! Had that happen and fortunately it reset after 5 to 10 minutes! It was not a breaker on that circuit and the extra current draw was not that high. Repeated it several times and decided it was probably the inrush current on my detector! Tapped another higher current circuit.