AutoCodes – Oldsmobile – P0307 Oldsmobile

P0307 Oldsmobile Code - Cylinder 7 Misfire Detected

Quick Answer

A misfiring cylinder causes slight variations in the rotational speed of the crankshaft. Common causes include Faulty spark plug 7, Clogged or faulty fuel injector 7, Faulty ignition coil 7. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P0307 Oldsmobile indicates Cylinder 7 Misfire Detected.
Common causes: Common causes include Faulty spark plug 7, Clogged or faulty fuel injector 7, Faulty ignition coil 7.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 991

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Aug 09, 2022

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0307 Oldsmobile Description

A misfiring cylinder causes slight variations in the rotational speed of the crankshaft. The Engine Control Module (ECM) can detect these variations by closely monitoring the crankshaft position sensor signal. The signals of the camshaft position sensors are used to determine which cylinder is misfiring. If the ECM detects a misfire rate sufficient to cause emission levels to exceed mandated standards, the Diagnostic Trouble Code (DTC) will be set. Under certain driving conditions, a misfire rate can be high enough to cause the catalytic converter to overheat, damaging the converter. The Malfunction Indicator Lamp (MIL) flashes when the converter is overheating, damaging conditions are present, and the DTC is set. The DTC will be set when the ECM detects a crankshaft rotation speed variation indicating a single-cylinder misfire rate sufficient to cause emissions levels to exceed mandated standards.

OBDII Code P0307 Oldsmobile - Cylinder 7 Misfire Detected - AutoCodes.com — P0307 Oldsmobile Code - Cylinder 7 Misfire Detected

What does this mean?

What are the Possible Causes of the DTC P0307 Oldsmobile?

Faulty spark plug 7
Clogged or faulty fuel injector 7
Faulty ignition coil 7
Fuel injector 7 harness is open or shorted
Fuel injector 7 circuit poor electrical connection
Ignition coil 7 harness is open or shorted
Ignition coil 7 circuit poor electrical connection
Insufficient cylinder 7 compression
Incorrect fuel pressure
Intake air leak

How to Fix the DTC P0307 Oldsmobile?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What does this mean?

Code Tech Notes

The P0307 code means that cylinder 7 is misfiring or is randomly misfiring. Start by checking for intake leaks and if no leaks are found the next step is to replace the spark plugs on cylinder 7. If the problem persists more tests need to be done to diagnose the problem, see "Possible Causes".

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0307 Oldsmobile code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0307 Oldsmobile Code

1. What does the OBDII code P0307 on an Oldsmobile indicate?

The code P0307 indicates that the engine control module (ECM) has detected a misfire in cylinder number 7. This means the cylinder is not firing properly, which can affect the engine's performance.

2. What are the common symptoms of code P0307 in an Oldsmobile?

Symptoms include rough idling, engine vibration, reduced fuel efficiency, the engine may stall, and the check engine light will likely be illuminated.

3. What can cause a P0307 code to appear on my Oldsmobile?

Common causes include faulty spark plugs, bad spark plug wires, a defective ignition coil, issues with the fuel injector, and low compression in cylinder 7, among others.

4. How can I fix the P0307 code on an Oldsmobile?

Repairs can vary based on the root cause but generally include replacing faulty spark plugs, repairing or replacing bad spark plug wires or ignition coils, fixing or replacing damaged fuel injectors, and addressing any mechanical issues like poor compression.

5. Is it safe to drive my Oldsmobile with a P0307 code?

Driving with a misfire can cause further damage to the engine. It is advised to address the issue as soon as possible to avoid potential costly repairs.

6. How do I diagnose the cause of a P0307 code on my Oldsmobile?

Diagnosis should start with a visual inspection of the spark plugs, spark plug wires, and ignition coil. Checking the fuel injector operation and measuring the compression in cylinder 7 with a compression tester can also help pinpoint the problem.

7. Can a P0307 code trigger the check engine light on my Oldsmobile?

Yes, a P0307 code will typically trigger the check engine light because it represents a misfire which the ECM recognizes as a problem that needs attention.

8. What tools are needed to diagnose and fix a P0307 code?

Tools may include a diagnostic scanner, a spark plug wrench, a compression tester, and a multimeter. Access to a professional mechanic or repair manual for your specific model can also be very helpful.

9. Could a P0307 code be a sign of a bigger problem in my Oldsmobile?

Yes, a misfire in a single cylinder could be symptomatic of broader issues such as engine timing problems, head gasket failures, or major engine wear and should be thoroughly investigated to prevent more severe problems.