GMC Yukon XL 2000–2006
Common on this vehicle:Warning lightLeakNoiseDoes not startLoss of engine power, no accelerationGauge or instrument faultStalls or shuts offHard start or long crank
Possible causes
4 causes not drawn
- Higher than expected oil consumption at 8600 GVW and above (accepted rate and consumption test)1
- P0300 after engine repairs: injector connectors crossed (cylinders 5-7 / 6-8)1
- Oil leak after cold start from frozen PCV system (rear main seal)1
- Slight roughness at idle with no DTCs (possible characteristic)1
The documents say what to doOnly records name itThe size of a node, the width of a link and the numbers are records matching this search, not likelihoods.
FaultCrate・GMC Yukon XL 2000–2006・Engine, 2004
Candidate cause (the documents say what to do)
Castech cylinder head porosity crack (gradual coolant loss)
Some vehicles may lose coolant gradually over time.
A very low percentage of cylinder heads with an embossed Castech logo may develop a porosity crack in a very specific area.
What to do
- Inspect the cylinder head to determine whether the casting was made by Castech.
- On a Castech casting, inspect around the five oil drain holes for witness marks of coolant seepage.
- The crack can be at any of the five cylinder head oil drains and shows as a clean or shiny area on an otherwise stained surface.
- Pressurizing the cooling system may reveal coolant, air, or both weeping in that area.
- Check whether the head is a Castech casting by looking for the casting logo on top of the intake port, under the rocker arm support rail and in the spring deck cavity portion of the cylinder head.
- If coolant witness marks are found, replace the entire cylinder head assembly.
Caution: If the heads are not Castech castings, follow normal diagnostic procedures to find the cause of the coolant loss.
In the records
No record states work done for this cause.
See the evidence (2 technical documents, 1 records)
Passages of the technical documents
2001-2006 GMC Envoy, Jimmy, Sierra, Yukon Models
General Motors (published by NHTSA) 2024-03-14
with 4.8L, 5.3L, or 5.7L VORTEC® GEN III, GEN IV V8 Engine
General Motors (published by NHTSA) 2024-03-14
Some vehicles may experience a gradual coolant loss over time.
General Motors (published by NHTSA) 2024-03-14
A very low percentage of cylinder head(s) manufactured with an embossed Castech logo may develop a porosity crack in a very specific area.
General Motors (published by NHTSA) 2024-03-14
Manufacturer’s documents
- Internal Coolant Leak from Cylinder Head Location 06-06-01-019C 2024-03-19
A cause or a result a complaint states is the owner’s view or what a dealer told them, not an established fact.
Put together by FaultCrate from public records and technical documents. The cause and the repair are for the workshop to decide with the vehicle in front of it. Counts are records, not failure rates.