I have a 2002 Chevy Silverado 1500/Z-71 with the 5.3L, 160K miles. My check engine light came on and after having it put on a machine was told it MAY be the intake manifold gasket. They didn’t sound real sure of themselves so wanted to get some feedback from other sources. Engine light is on and it starts and runs fine in warm weather. In weather 50 degrees and below the engine revs way up until the engine warms up. I ran my own test by spraying a little WD-40 around the intake and got a reaction around the number 8 cylinder. Am I on track? Do I need to replace the gasket? Have been reading about numerous GM gasket failures mostly on the V6 types and am not seeing any antifreeze in my oil.

IMO - I you get a reaction from spray - carb cleaner, brake cleaner or even the WD-40 where it shouldn't be there's a problem there,

T
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Tom Greenleaf - MetroWest, Boston

We would need the exact code number to have any idea if they are on the right track. Those manifolds are known for coolant leaks at the intake gasket but vacuum leaks are a little more rare.




78 Corvette Pace Car For Sale-18k mi orig-Florida

I think the 5.7 is more common on coolant leaks. The 5.3 has a very common vacuum leak problem. With a reaction from spray that is likely the cause.

Jeff