Check Engine Light (Timing Related): Repair in Salt Lake City, UT
Scott's Auto & Clutch Repair specializes in timing system diagnosis and has been resolving timing-related check engine codes for Salt Lake City drivers since 1990.
Understanding Check Engine Light (Timing Related)
Codes P0016 and P0017 concern the relationship between crankshaft and camshaft position signals. P0340 and P0341 concern the camshaft-position sensor circuit or signal performance. These codes do not, by themselves, prove the timing chain is worn; diagnosis may include oil condition, wiring, sensors, variable valve timing, and mechanical timing.
Is My Check Engine Light a Timing Problem?
The check engine light is on and the car may run rough, hesitate on acceleration, or feel down on power, these are the typical signs of a timing-related fault code. You might also notice the engine cranking longer than usual before it starts.
If the car runs normally but the light is on, the fault may be stored from a prior event. If the engine feels off, rough idle, stumbling, or loss of power. The timing system is likely affecting combustion and the issue should be diagnosed promptly.
What Causes Check Engine Light (Timing Related)?
These are possible causes to inspect. Tell us which symptoms you notice; the checks below help guide diagnosis but do not confirm a failed part on their own.
Timing Chain Stretch
As the timing chain wears at every roller-pin contact, the chain gets measurably longer over time. That extra length shifts the camshaft position relative to the crankshaft. The ECM detects the mismatch through the cam and crank sensors and stores a correlation code. The engine still runs but at the wrong timing, and the underlying mechanical problem keeps progressing.
P0016 or P0017 code alongside cold-start rattling and possibly rough running. May appear intermittently first, becoming consistent as stretch increases. Common past 100,000 miles, especially with infrequent oil changes.
Failed Cam Sensor
The cam position sensor reads a toothed wheel on the camshaft to tell the ECM where the cam is. When the sensor fails (cracked magnet, broken wire inside the harness, corroded connector pins), it sends garbled or missing data. The ECM sees that as a timing fault even though the chain itself is healthy and timing is mechanically correct.
Timing code without other driveability symptoms. Engine runs normally and there's no startup rattle. Code is consistent and doesn't fluctuate with engine temperature. Wiring, connector, or the sensor itself is the typical culprit.
VVT System Issue
Variable valve timing systems use oil pressure routed through solenoid-controlled passages to rotate the cam phaser. When old or sludged oil clogs those passages, the phaser can't move freely. The actual cam timing deviates from what the ECM commanded, which trips the same correlation codes a stretched chain produces. The chain itself is fine; the oil flow isn't.
Code appears during low-speed or idle operation, sometimes clearing at higher RPM. Rough cold idle and reduced fuel economy are common accompaniments. Symptoms often improve noticeably after an oil change if sludge is the root cause.
Not sure which applies to you? Call (801) 485-4089 or text us: free diagnosis at our Salt Lake City shop.
When Should You Bring Your Car In for Timing Code Diagnosis?
Timing codes on interference engines (most modern 4-cylinders) are time-sensitive. A stretched chain that's jumped a tooth can cause pistons and valves to collide, that's catastrophic engine damage. Don't put off diagnosis if the light is on and the car is running rough.
The repairs differ significantly: a sludge-clogged VVT system may resolve with an oil flush; a stretched chain requires mechanical replacement. Ordering parts based on the code number alone risks the wrong repair, live data diagnosis separates the two.
Who to Trust for Timing System Repair in Salt Lake City
Diagnosis starts with live scan data, cam and crank sensor waveforms, VVT actuator commanded vs. actual position, and fuel trim corrections. This separates a mechanical chain problem from a sensor fault or VVT clog, which are very different repairs at very different costs. Our timing chain service is one of our highest-volume specialized repairs.
Scott's Auto & Clutch Repair has been doing timing system work in South Salt Lake since 1990. If you're seeing timing codes paired with startup rattling, call us, we'll help you assess urgency before you bring the vehicle in.
Free diagnosis. Written estimate before any work begins. No surprises.
Where to Get Help with Check Engine Light (Timing Related)
Scott's Auto & Clutch Repair, serving Salt Lake City drivers since 1990.
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Mon-Fri: 9:00 AM - 5:30 PM
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Frequently Asked Questions: Check Engine Light (Timing Related)
How much does timing system repair cost?
A VVT solenoid replacement runs $150–$400. An oil service to restore VVT pressure is $80–$120. A full timing chain replacement is $800–$2,500 depending on the engine. Diagnosis is free, we distinguish solenoid issues from chain stretch with live data before recommending parts.
What does a P0016 code mean exactly?
P0016 means the camshaft position sensor and crankshaft position sensor disagree about engine timing on Bank 1. The cam appears to be in a different position than the crank says it should be. The mismatch is usually a stretched timing chain that has shifted the cam relationship, but it can also be a failed sensor, a clogged VVT solenoid, or low oil pressure starving the timing system.
Can low oil cause timing codes?
Yes. Variable valve timing systems use oil pressure to move the cam phaser. When oil level is low or pressure is reduced from worn pump or sludged passages, the phaser can't respond fast enough to commanded changes. The ECM detects the slow response and stores a correlation code, even though the chain itself may be fine.
How do you diagnose VVT problems versus chain stretch?
Live scan data is the key. We watch the VVT actuator's commanded position versus actual position in real time across various engine speeds. Slow or unresponsive phaser action with healthy oil pressure points to a VVT solenoid or sludged passages. Consistent mechanical offset that doesn't respond to commands points to chain stretch. The repairs are very different.
Not Sure This Is Your Issue?
Browse related symptoms, drivers often confuse these for one another.
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What Our Customers Say
Real reviews from Salt Lake Valley drivers
“This was my second time using Scott's. The power steering went out in my truck. Scott got it in that day and had it fixed in a couple of hours. I couldn't recommend this shop more!”
“This is my mechanic — he is great.”
“This guy did great work on a couple of things we had done on our vehicle. All in all great work.”
“My wife's Subaru was having a timing issue with the wipers. I brought it to Scott's and they diagnosed the problem quickly and torqued a bolt in about 5 seconds that fixed it. They didn't charge us and we will definitely be coming back here for auto service with Subarus.”
Experiencing Check Engine (Timing)?
Contact Scott's Auto & Clutch Repair today for a free diagnosis. We'll get your vehicle running right.
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144 W Crystal Ave, South Salt Lake, UT 84115