QuestionI have a 2003 Yukon with the 5.3 and need to replace the intake gasket due to hesitating and engine code for lean banks. I saw the other post with the procedure. The parts guy at the dealership said that the intakes often warp as well and are often replaced at the same time as the gasket. Do I need to worry about this and how do you determine if it is warped?
AnswerHi
After removal of manifold,
Use a straight edge for this procedure......
The intake plenum should also be checked for excessive warpage that may cause an uneven clamping pressure of the seal. If the plenum is found to be warped it will need to be replaced. Service Information states, "An intake manifold with warpage in excess of 3 mm (0.118 in) over a 200 mm (7.87 in) area should be replaced". Intake warpage is measured at the gasket sealing surfaces, and should be measured within a 200 mm (7.87 in) area. This measurement is across only two of the intake runner port openings. Measurements taken across the entire distance of all four intake runner ports will lead to unnecessary manifold replacements.
I have preformed this repair well over 50 times and have had only 1 manifold with a greater warpage than 3mm across 2 (TWO) ports ONLY. Not across the whole manifold.(4 ports).This is where ALOT of mistakes are made.
The one I did have was the first one I ever did, and it was obviously warped. (twisted).
Not saying yours MAY NOT be warped, but it is more UNCOMMON than common, at least here in the deep south.
This MAY not hold true in colder climates which I have no experience working in.
I do hope this helps
Please follow post back, if needed.
Good Luck
Pawl
