Riviera V6-3.8L SC VIN 1 (1995)
while monitoring for ESC activity and listen for audible spark knock. If ESC is constantly active under light to medium acceleration and AUDIBLE
SPARK KNOCK present, then perform the following:
1.
Insure that gasoline quality is not the cause of the condition.
2.
Ask the vehicle owner if there has been any noticeable oil consumption.
Important:
Field data suggests that the continuous spark knock condition can occur in some vehicles as a result of consuming one quart of oil in two
thousand miles. Field data further suggests that consuming one quart of oil in three thousand miles does not result in continuous spark knock.
3.
Remove all spark plugs and visually inspect the plugs for any evidence of oil consumption or oil fouling.
4.
If an oil fouled plug is found, as described in step 3, remove the valve cover on the affected bank(s).
5.
If no suspicious spark plug is found, remove both valve covers.
6.
Remove the intake and exhaust valve springs from the suspect cylinder(s).
7.
Remove the valve stem seals from the suspect cylinder(s).
8.
Inspect the removed valve seals for a broken retaining band. Refer to the illustration.
9.
Replace seals that have broken retaining bands with new seals.
10.
Reassemble the engine.
11.
Run GM Top Engine Cleaner through the engine to remove excessive carbon deposit build up.
^
Warm the engine up to operating temperature.
^
Remove the fuel pressure regulator vacuum hose where it connects to the vacuum tree.
^
Install a length of dealer supplied vacuum hose to the vacuum tree.
^
Inject GM Top Engine Cleaner through the dealer supplied vacuum hose with the engine running at about 1000 rpm until the spray can is
empty.
^
Reinstall the original fuel pressure regulator vacuum hose.
12.
Test drive and verify that the condition has been corrected as outlined in the "SERVICE INFORMATION" section in this bulletin.
Parts Information
PARTS INFORMATION
Parts are currently available from GMPSO.
WARRANTY INFORMATION
Warranty Information
