Experiencing a sudden, jarring jerk in your 2008 Buick Lucerne when you accelerate, especially after a heavy throttle input, can be unsettling. It’s even more concerning when your OBD2 scanner isn’t showing any trouble codes. You’re not alone if you’ve felt that lurch, like being rear-ended, right after pressing the gas pedal from a standstill in your Lucerne. Many drivers report this issue, particularly in lower gears, and it can persist even after routine maintenance.
This intermittent jerking and hesitation, often more pronounced in city driving and less noticeable on the highway, can lead to frustration. You might have even performed recent maintenance like transmission fluid and filter changes, oil changes, or wheel bearing replacements, hoping to resolve the issue, only to find the problem returns. The fact that your 2008 Buick Lucerne OBD2 system isn’t registering any fault codes despite these symptoms adds another layer of complexity to diagnosing the root cause.
While the absence of OBD2 codes might initially seem reassuring, it doesn’t rule out potential mechanical or electrical issues. Intermittent problems, especially those related to throttle response and fuel delivery, can sometimes occur without immediately triggering diagnostic trouble codes. Let’s explore some potential culprits behind this “missing” OBD2 situation and the persistent jerking after heavy throttle in your 2008 Buick Lucerne.
One area to investigate, despite the recent transmission service, is the transmission itself. Although you had the fluid and filter changed, internal issues within the transmission, such as valve body problems or torque converter issues, could still be at play. These might not always immediately set off OBD2 codes, especially if the issue is just beginning or is more mechanical than electrical.
Another potential cause, and one that aligns with the symptoms of jerking and hesitation, could be related to your engine’s ignition system. While you mentioned a good service history, the age of your 2008 Buick Lucerne means components like spark plugs and ignition coils could be wearing out. Faulty spark plugs or weak ignition coils can lead to misfires, particularly under heavier loads like acceleration, which could manifest as jerking. A thorough inspection of the spark plugs and ignition system is a worthwhile step, even without error codes.
Fuel delivery issues could also be contributing to the problem. A partially clogged fuel filter or a failing fuel pump might not be delivering consistent fuel pressure, especially when the engine demands more fuel during acceleration. This fuel starvation can cause hesitation and jerking. Similarly, issues with the fuel injectors themselves could lead to inconsistent fuel delivery and similar symptoms.
Throttle position sensor (TPS) problems, although less likely to be completely undetected by OBD2, could still be a factor. A slightly faulty TPS might send incorrect signals to the engine control unit (ECU) about the throttle position, leading to erratic engine behavior, especially during transitions like heavy throttle application.
Given that your 2008 Buick Lucerne OBD2 system is currently “missing” any codes related to this issue, a systematic diagnostic approach is crucial. While a generic OBD2 scan might not reveal anything, a more in-depth scan using professional-grade diagnostic tools could uncover pending codes or provide more detailed sensor readings that might point to the source of the problem. It’s also advisable to have a qualified mechanic perform a hands-on inspection, checking the components mentioned above – transmission, ignition system, fuel system, and throttle system – to pinpoint the cause of the jerking and hesitation you’re experiencing. Don’t dismiss the issue simply because the OBD2 system isn’t immediately flagging errors; intermittent problems often require more thorough investigation.
