2014 - 2021 Corvette: Service Buletin: #PIP5212C: Concern Of An Engine Thermostat Tick Noise And/Or Running Hot - (Mar 30, 2021)

#PIP5212C: Concern Of An Engine Thermostat Tick Noise And/Or Running Hot - (Mar 30, 2021)

Supersession Statement

This PI was superseded to update Model Years. Please discard PIP5212B.

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Correction

A vehicle may have a concern of the engine running hot and/or has a tick noise from the thermostat.   

Recommendations / Instructions

Inspect the position of the head gasket locating tabs, to determine if the head gasket(s) has been possibly installed backwards.

Per the attached pictures, the head gasket locating tabs for both of the engine cylinder banks should be toward the front of the engine.

1. Bank 1 tab near cylinder 3

2. Bank 2 tab near cylinder 4

3. Is the front of the engine  

If the head gasket locating tabs are found to be closer to cylinders 5 or 6, this indicates the head gaskets were installed incorrectly restricting the engine coolant flow.

Replace the head gasket to repair for this concern. 

Note: GEN5+ engines (L82, L84, L87 all model years).

This noise can sound more like a scraping noise (similar to a failed bearing type noise)on these engines, generally the techs are hearing it from the water pump area and it goes away when the belt is removed.  Most likely the noise showed up after the heads had been recently removed (we haven’t seen any that were built that way from the factory).