Ask a Master Tech: Random Misfires, Service Stabilitrak & Bad Vibrations
Ask a Master Tech: Random Misfires, Service Stabilitrak & Bad Vibrations
In today’s Ask a Master Tech column, we help Corvettes with random misfires, bad vibrations, and multiple Service Stabilitrak warnings.
[Editor’s Note: Hello, folks, please welcome Michael Salemme to the CorvetteForum writing team. Salemme spent the last three decades of his life in the automotive industry, including 17 years at a General Motors dealership where he maintained, serviced, diagnosed, and repaired several Corvette generations and achieved the title of Master Tech. Given his experience, we’ve decided to test out a potential column format where the goal is to dive into common repairs and fixes for our beloved Corvettes. Please note that, in this introductory post, we sourced our own questions, but going forward, hope CorvetteForum members will submit questions. Cheers!]Misfire Misery
Hello, Master Tech Mike,
I hope you can help me! I have a 2010 Corvette and, even though it has close to 90,000 miles, it’s still my baby. My car suffers from random misfires on all the cylinders, I notice it happens more on cold or rainy days. But when I bring my car to the dealer, the problem never happens. I have spent lots of money to diagnose the problem over the last year, and the techs are no help. Do you have any suggestions?
-Frank from Philly
Hi Frank,
This is a serious problem and I think I have the answer. If your PCM has P0300 through P0308 stored in history, that is proof that all 8-cylinders are experiencing the same problem. I would check with a scan tool with live data to see which cylinders are currently misfiring, some times an adjacent misfire can cause it to spread to other cylinders on a graph. When you stated it happens when it’s rainy, this eliminates a fuel problem.
Some 2010-2011 Corvette’s had problems with their spark plug wires, specifically the end that attaches to the coil side, there was a manufacturing issue that caused the retaining ring in the wire end to come loose. This causes the wire to detach from the ignition coil causing the misfires.
I recommend changing your spark plug wires with a complete set from AC Delco and, while you’re there, replace your spark plugs as well. GM recommends changing the plugs at 100K miles, but because of the misfires, it’s a good idea to change them now.
Bad Vibrations at Cruising Speeds
Dear Master Tech Mike,
I have a 2016 Corvette with the 8-speed automatic transmission. At 40,000 miles, I started to experience a bad vibration and shudder when driving between 35 -75 MPH and it happens through all gears. I have brought it to a few local shops and a transmission shop. They told me my transmission needs to be rebuilt or replaced. I now have 76,000 miles and my warranty is expired, what should I do, is there a repair to fix this?
-Bill from San Diego
Hi, Bill,
It seems you’re not the only one to experience this problem. If you have a 2015-2019 Corvette with the 8-speed auto, you could be dealing with torque converter clutch shudder. The (TCC) shudder condition is related to moisture content in the transmission fluid. The current fluid tends to be hygroscopic, or absorbs moisture, which increases the chance of (TCC) shudder.
We recommend going to your local Chevrolet dealer because there is a service bulletin that covers the problem (#16-NA-175) and special tools are required. The fix involves flushing your transmission twice with the new updated Mobil 1 Synthetic LV ATF HP transmission fluid (GM Part Number 19417577). Once complete a road test will confirm the repair.
Read the full bulletin HERE.
Service Stabilitrak Back Again
Dear Master Tech Mike,
I have a 2008 Corvette with a service Stabilitrak message on the dashboard. My mechanic checked for codes and found CO 710 – steering wheel position performance. I had the sensor replaced at my local Chevy dealer. Two months later the code came back, could it be a bad sensor ?
-Paul T. from Dallas
Hi Paul,
That can be frustrating, but there is a cure for this problem. 2005-08 Corvettes with the tilt and telescoping steering column are susceptible to this issue. When the column is telescoped in and out the female terminals move on the male terminals of the steering wheel position sensor causing high resistance in the connector.
The fix is relatiely simple. First, go to your local GM dealer and purchase a retaining clip for the connector, part # 1919794. Then remove the lower closeout panel under the steering column and locate the SWPS connector on the lower center of the steering column. And install the clip to the back of the connector. It will act as a locking device and prevent any future movement of the terminals. Clear the vehicle’s history DTCs (Diagnostic Trouble Codes) and you’re good to go.
Photos: General Motors; CorvetteForum & CorvetteForum
