Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
Does the engine tapping noise occur all the time,cold or hot.
Engine just serviced. After pickup on the way home i heard a tapping sound comming from the engine like a stuck lifter or something. Tapping when engine is cold or hot. Can hear at idle and while driving.Then engine light came on steady. Checked gas cap, filled up with 89 oct (reg use 87 oct) no help. Returned to my mech. Code said engine knock sensor. He has inspected everything and can find nothing worng, but the tapping is still there. What next, change the sensor ro any other ideas?
Crap, not sure, the HHR is in the shop.It's not the supercharged one. I'll give them a call. I hpe this does not require a engine tear down.
This PI was superseded to update model years. Please discard PIP4495B.
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
A technician may find noise coming from the cylinder head. This may be due to loss of oil pressure.
This concern may be caused by debris clogging the oil feed restrictor in the cylinder head passage. The oil feed hole has a small inner diameter and may clog if debris or excessive RTV or similar type gasket/sealer has dislodged and become stuck in this passage. Anytime RTV or similar sealer is used, care must be taken not to use excessive amounts that can become dislodged causing future concerns. This restrictor is located in the oil feed passage to the cylinder head and cannot be inspected/cleaned without cylinder head removal. NOTE: The restrictor is not available separate from the cylinder head. See callout #2.
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To diagnose this concern: Using a mechanical oil pressure gauge, check/compare the oil pressure in the block with the oil pressure in the cylinder head. The block can be checked by removing the oil pressure sender or another engine block oil gallery plug. The oil pressure to the cylinder head can be checked by removing one of the oil galley plugs in the cylinder head. See callout #1.