GMC Yukon 2000–2006
Record by record
2 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
Work done
How it is said to have ended
- says it came back2
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 (2)
Known issuesCastech cylinder head porosity crack (gradual coolant loss)1
Owner complaint2004 GMC YUKON ・ 2013-09-03
Slug buildup, oil pressure loss, and coolant loss
1Fault
2Finding the cause
3Correction
Read the sentences of the record
- Fault
- MY CAR BEGAN TO HAVE A BUILD UP OF SLUGS AND BEGAN LOOSING OIL PRESSURE AND COOLANT AND NEEDED OIL ADDED AND COOLANT FREQUENTLY.
- Cause
- I WAS ADVISED TO CHANGE THE OIL FREQUENTLY TO CLEAN THE SLUG OUT BUT IT CONTINUED TO BUILD UP AND THE MYSTERY OF LOOSING COOLANT OIL PRESSURE HAS BOTTOMED OUT TWO MORE TIMES AND I FOUND A ARTICLE ON THE INTERNET THAT A NUMBER OF GMC VEHICLES INCLUDING MINE WERE BUILT WITH DEFECTIVE CYLINDER HEADS DUE TO CRACKS OVER TIME WHICH ALLOWS COOLANT TO LEAK INTO ENGINE AND MIX WITH THE OIL WHICH BUILDS UP SLUG.
- Remedy
- THE SLUGS WERE CLEANED AND A NEW OIL PUMP WAS PLACED BECAUSE OF THE BUILD UP OF SLUGS.
ENGINE AND ENGINE COOLING1
Manufacturer communication2006 GMC YUKON ・ 2019-09-16
Low or No Oil Pressure and Engine Noise Service Information
1Fault
- Customers may complain of low oil pressure, no oil pressure and/or engine noise, possibly with P0521, which may result from a sticking oil pump pressure relief valve.
- It may be intermittent if the valve frees up when the engine cools down.
2Finding the cause
Not stated
3Correction
Repair
- If SI diagnosis isolates low mechanical oil pressure at the oil filter housing and oil pressure sensor, replace the oil pump and flush the oil cooler lines (if equipped).
- Clean the inside of the oil pan, change the oil and filter, and re-evaluate the concern.
Caution
- If an engine noise is noticed after replacing the oil pump, follow the SI diagnosis and repair the engine as necessary.
Read the sentences of the record
From the manufacturer’s document
- Applies to：Applies to the 2006 - 2014 GMC Yukon (note: the years run later than the years this service covers).
- Applies to：These aluminum V8 engine RPOs are covered: L76, L77, L92, L94, L99, L9H, LC9, LH6, LH8, LH9, LMG, LS2, LS3, LS4, LS7, LS9, LSA, LZ1.
- Condition：Customers may complain of low oil pressure, no oil pressure and/or engine noise, possibly with P0521, which may result from a sticking oil pump pressure relief valve.
- Condition：It may be intermittent if the valve frees up when the engine cools down.
- Repair：If SI diagnosis isolates low mechanical oil pressure at the oil filter housing and oil pressure sensor, replace the oil pump and flush the oil cooler lines (if equipped).
- Repair：Clean the inside of the oil pan, change the oil and filter, and re-evaluate the concern.
- Caution：If an engine noise is noticed after replacing the oil pump, follow the SI diagnosis and repair the engine as necessary.
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 low oil pressure, no oil pressure, and/or engine noise. Technician will need to replace the oil pump, flush the oil cooler lines.