GMC Yukon XL 2000–2006
Common on this vehicle:NoiseWarning lightLeak
Record by record
5 records state a cause or a remedy. Each record is shown as short labels in the order fault → finding the cause → correction. Press a label to narrow to the records that state it.
Symptom
Component named as the cause
A ribbon is as wide as the records that state both of its ends (only the commonest are drawn). A record that names several symptoms or components runs through each. Orange is records that say the fault came back or was not fixed. Results come from owners’ reports only; one that does not say is “result not stated”. None of this is a likelihood of a cause or a rate at which work succeeds.
Read the records one by one (3)
Known issuesSingle-cylinder misfire (P0300-P0308) and/or chirp, squeak or tick at camshaft speed: worn cam lobe / lifter, valve or valve spring3
Manufacturer communication2002–2006 GMC YUKON XL DENALI ・ 2023-05-06
Diagnostic tip: valve, lifter or camshaft issue
1Fault
- Misfire, chirp, squeak, squeal or tick noise, or MIL illuminated.
- DTCs P0300 (engine misfire detected) and P0301 through P0308 (misfire detected on cylinders 1 through 8) are listed.
2Finding the cause
Possible causes
- Possible causes: worn camshaft lobe and/or lifter roller, a sticking valve, valve leakage, a broken valve spring, or a collapsed AFM lifter.
Steps to confirm (in the document’s order)
- A verified noise is not eliminated by canceling fuel injectors and occurs at camshaft speed (half of crankshaft speed).
- If applying pressure to the valve side of the rocker changes the noise, a lifter and/or cam lobe concern on that cylinder is most likely.
- Disconnect the coils and injectors on one bank, run the engine with that valve cover removed, back off the rocker arm a couple of turns and listen for a change in the noise.
- Measure cam lobe lift at the pushrod side of the rocker arm and compare with other rockers on the same bank; the misfiring or ticking cylinder should have clearly less lift.
- A good indicator of a sticking valve is misfires that keep counting on an aggressive deceleration with engine braking.
3Correction
Repair
- If a worn camshaft lobe or lifter roller is found, replace the camshaft and all lifters, and the plastic lifter guide for the affected lifter.
Caution
- A damaged cam lobe is easy to overlook through the lifter bores, and unworn lifter rollers do not mean the cam lobes are okay; inspect both carefully.
Read the sentences of the record
From the manufacturer’s document
- Applies to:Applies to GM passenger cars and trucks, 2002 through 2023, with V6/V8 pushrod engines.
- Condition:Misfire, chirp, squeak, squeal or tick noise, or MIL illuminated.
- Condition:DTCs P0300 (engine misfire detected) and P0301 through P0308 (misfire detected on cylinders 1 through 8) are listed.
- Confirm:A verified noise is not eliminated by canceling fuel injectors and occurs at camshaft speed (half of crankshaft speed).
- Cause:Possible causes: worn camshaft lobe and/or lifter roller, a sticking valve, valve leakage, a broken valve spring, or a collapsed AFM lifter.
- Confirm:If applying pressure to the valve side of the rocker changes the noise, a lifter and/or cam lobe concern on that cylinder is most likely.
- Confirm:Disconnect the coils and injectors on one bank, run the engine with that valve cover removed, back off the rocker arm a couple of turns and listen for a change in the noise.
- Confirm:Measure cam lobe lift at the pushrod side of the rocker arm and compare with other rockers on the same bank; the misfiring or ticking cylinder should have clearly less lift.
- Caution:A damaged cam lobe is easy to overlook through the lifter bores, and unworn lifter rollers do not mean the cam lobes are okay; inspect both carefully.
- Repair:If a worn camshaft lobe or lifter roller is found, replace the camshaft and all lifters, and the plastic lifter guide for the affected lifter.
- Confirm:A good indicator of a sticking valve is misfires that keep counting on an aggressive deceleration with engine braking.
- Confirm:A broken valve spring may stay stacked together and be hard to see; lightly push on different places on the springs with a small hammer handle.
Open the manufacturer’s document (PDF) ↗ The points above were read from this document.
- Remedy
- This diagnostic tip bulletin provides additional information on how to diagnose a possible valve, lifter or camshaft issue.
Manufacturer communication2000–2006 GMC YUKON XL ・ 2017-08-15(2 earlier editions of this document folded here)
Engine Misfire and Service Engine Soon Lamp Information
1Fault
- With the SES light on, a P0300-P0308 DTC is found with misfires counting on a single cylinder, which may or may not be felt.
- The noise may be described as a chirp, squeak, squeal or tick and may increase off of idle.
2Finding the cause
- Valve Spring: broken
- Active Fuel Management Lifter: defective
- Valve: defective
- Camshaft Lobe: worn
- Lifter Roller: worn
Possible causes
- A worn cam lobe on this engine family generally makes a consistent chirp, squeak, squeal or tick at camshaft speed and/or a misfire with a P0300-P0308 DTC.
Steps to confirm (in the document’s order)
- Press on the rocker arms with a wooden hammer handle while the noise is present; if pressing the valve side of a rocker changes the noise, a lifter and/or cam lobe concern on that cylinder is most likely.
- Measure cam lobe lift at the push rod side of the rocker arm; it will differ from the SI specification but should be similar to the other rockers on the same bank.
- A bore scope or pen light may help when inspecting the cam lobes through the lifter bores.
- A good sign of a sticking valve is that misfires keep counting during an aggressive deceleration with engine braking.
- The Cylinder Leakage Test in SI should typically isolate valve leakage by showing excessive leakage past an intake or exhaust valve compared with the others.
3Correction
Repair
- If a worn cam lobe or lifter roller is found, replace the camshaft and all lifters per SI, plus the plastic lifter guide for the affected lifter (for the 2010 model year, all the plastic lifter guides).
- If force is needed to tap the valve off its seat, there is excessive carbon build up, which may be repaired by decarboning the engine.
Read the sentences of the record
From the manufacturer’s document
- Applies to:Applies to 1999-2013 GMC Savana, Sierra and Yukon (with a V8 engine per the model list) (note: the Yukon years run later than the years this service covers).
- Condition:With the SES light on, a P0300-P0308 DTC is found with misfires counting on a single cylinder, which may or may not be felt.
- Condition:The noise may be described as a chirp, squeak, squeal or tick and may increase off of idle.
- Cause:A worn cam lobe on this engine family generally makes a consistent chirp, squeak, squeal or tick at camshaft speed and/or a misfire with a P0300-P0308 DTC.
- Confirm:Press on the rocker arms with a wooden hammer handle while the noise is present; if pressing the valve side of a rocker changes the noise, a lifter and/or cam lobe concern on that cylinder is most likely.
- Confirm:Measure cam lobe lift at the push rod side of the rocker arm; it will differ from the SI specification but should be similar to the other rockers on the same bank.
- Confirm:A bore scope or pen light may help when inspecting the cam lobes through the lifter bores.
- Repair:If a worn cam lobe or lifter roller is found, replace the camshaft and all lifters per SI, plus the plastic lifter guide for the affected lifter (for the 2010 model year, all the plastic lifter guides).
- Confirm:A good sign of a sticking valve is that misfires keep counting during an aggressive deceleration with engine braking.
- Repair:If force is needed to tap the valve off its seat, there is excessive carbon build up, which may be repaired by decarboning the engine.
- Confirm:The Cylinder Leakage Test in SI should typically isolate valve leakage by showing excessive leakage past an intake or exhaust valve compared with the others.
- Confirm:The two pieces of a broken valve spring can stay stacked together and be hard to see, so lightly push on different places on the springs with a small hammer handle.
Open the manufacturer’s document (PDF) ↗ The points above were read from this document.
- Remedy
- This Preliminary Information communication provides information to the technician about vehicles that have a Service Engine Soon Malfunction Indicator Lamp on, engine misfire, and/or engine noise. Technician may find Diagnostic Trouble Codes P0300-P0308. If published Service Information diagnostics does not isolate the cause of this concern technician should check for a worn camshaft lobe and/or lifter roller, a sticking valve, valve leakage, a broken valve spring, and a collapsed active fuel management lifter.
Manufacturer communication2000–2006 GMC YUKON XL ・ 2017-08-15
Service Engine Soon Lamp and Engine Misfire Information
1Fault
2Finding the cause
3Correction
What the documents say to do
Single-cylinder misfire (P0300-P0308) and/or chirp, squeak or tick at camshaft speed: worn cam lobe / lifter, valve or valve springConfirm
- If pressing on the valve side of the rocker changes the noise, a lifter and/or cam lobe concern on that cylinder is most likely.
Repair
- If a worn camshaft lobe or lifter roller is found, follow SI procedures to replace the camshaft and all lifters.
- Also replace the plastic lifter guide for the lifter that had the damaged cam lobe and/or lifter roller.
Caution
- A damaged cam lobe is easy to overlook when inspecting through the lifter bores; unworn lifter rollers do not mean the cam lobes are okay.
Read the sentences of the record
Open the manufacturer’s document (PDF) ↗ What is shown here is NHTSA’s summary; the procedure is in the document itself.
- Remedy
- This Preliminary Information communication provides information to the technician about vehicles that have a Service Engine Soon Malfunction Indicator Lamp on, engine misfire, and/or engine noise. Technician may find Diagnostic Trouble Codes P0300-P0308. If published Service Information diagnostics does not isolate the cause of this concern technician should check for a worn camshaft lobe and/or lifter roller, a sticking valve, valve leakage, a broken valve spring, and a collapsed active fuel management lifter.
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