2001 Silverado knock sensor corroded.

While helping my brother replace the rear knock sensor on his 2001 5.3 Silverado we found that the cavity the knock sensor was in was almost full of coolant which corroded the sensor and plug. Where could this much coolant be coming from?

While helping my brother replace the rear knock sensor on his 2001 5.3 Silverado we found that the cavity the knock sensor was in was almost full of coolant which corroded the sensor and plug. Where could this much coolant be coming from?


the two piece intake manifold has a filler material that is supposed to keep out any corroding chemicals/water etc. the material GM used does not work. also [my first hand experience] rodents like to roast the acorns in there.

my guess is that the throttlebody gasket is leaking/hoses to it etc... the throttle body has coolant flowing thru it to heat up the air flowing to the engine. gaskets are a problem with the water pump and throttle body .

when closing up the intake upper/lower portion use silicone sealant between these two pieces so nothing can get in there.

replacing both ks would be good and making sure that the wiring /connectors have no corroding damage. the sensors require a good clean ground connection as well as output terminal

pressure test for leaks