GMC Yukon 2000–2006
Common on this vehicle:Leak
issueCastech cylinder head porosity crack (gradual coolant loss)Remove
Possible causes
Causes with no correction stated (1)
Causes the records name for which no check or repair is stated, in a technical document or in a record. Press one for the records that name it.
- Engine
- Engine: failed (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 2000–2006・Engine
Candidate cause (the documents say what to do)
Castech cylinder head porosity crack (gradual coolant loss)
Applies to: 4.8L, 5.3L only
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.
What is needed
- Parts and materials
- The entire cylinder head assembly (if coolant witness marks are found)
- Labor time
- Not stated
- Special tools
- Not stated
- Scan tool
- Not stated
Only what the technical documents state. "Not stated" does not mean not needed.
In the records
- Engine: replaced 1（result not stated: 1）
- Oil Pump: replaced 1（says it came back: 1）
- Slug: cleaned 1（says it came back: 1）
See the evidence (2 technical documents, 5 records)
Passages of the technical documents
The bulletin covers 2001-2006 GMC Envoy, Jimmy, Sierra and Yukon models.
2001-2006 GMC Envoy, Jimmy, Sierra, Yukon Models
General Motors (published by NHTSA) 2024-03-14
It applies to the 4.8L, 5.3L or 5.7L Vortec Gen III / Gen IV V8.
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 lose coolant gradually over time.
Some vehicles may experience a gradual coolant loss over time.
General Motors (published by NHTSA) 2024-03-14
A very low percentage of cylinder heads with an embossed Castech logo may develop a porosity crack in a very specific area.
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
Records
- Slug buildup, oil pressure loss, and coolant loss Owner complaint 2013-09-03
- Engine losing coolant with no apparent external leakage Owner complaint 2016-07-18
- Coolant drain into engine block from faulty cylinder head Owner complaint 2015-01-03
- 5.3L GM engine camshaft delamination and engine replacement Owner complaint 2013-09-13
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.