its a head or head gasket issue....i would have a leak down or combustion leak test performed....
here are a few service bulletins
Bulletin No.: 00-06-02-001
File In Section: 06 Engine/Propulsion System
Date: January, 2000Subject:
Engine Running Hot, Overheating and/or Loss of Coolant (Polish Radiator Filler Neck and Replace Radiator Cap)
1999-2000 Passenger Cars and Trucks with Composite Radiator End Tank
Some customers may comment on one or more of the following conditions:
|^||Engine running hot |
|^||Engine overheating, and/or |
|^||Loss of coolant/low coolant message |
The radiator filler neck may have an imperfection in the sealing surface.
CorrectionImportant: DO NOT REPLACE THE RADIATOR.
Using a piece of 400 grit wet/dry sandpaper backed with a flat piece of wood, polish the filler neck sealing surface using a circular motion.
Replace the radiator pressure cap with a cap of the same part number as shown in the GM Service Parts Catalog.
For vehicles repaired under warranty, use:Labor Labor Operation Description Time J3020 Cap, Radiator Filler - Replace0.2 hr
File In Section: 06 - Engine/Propulsion System
Bulletin No.: 00-06-01-016
Date: August, 2000
Enhanced Aluminum Engine Component Thread Repair Process
1993 Cadillac Allante
1993-2001 Cadillac Eldorado, Seville
1994-1999 Cadillac DeVille Concours
1996-2001 Cadillac DeVille
2000-2001 Cadillac DeVille Touring
1997-2001 Chevrolet Corvette
1998-2001 Chevrolet Camaro
1995-2001 Oldsmobile Aurora (V8)
1999-2001 Oldsmobile Intrigue
2001 Oldsmobile Aurora (V6)
1998-2001 Pontiac Firebird
with 2.2 L, 3.5 L, 4.0 L, 4.6 L or 5.7 L Engine
(VINs F, H, C, 9, Y, G, S - RPOs L61, LX5, L47, L37, LD8, LS1, LS6)
An enhanced thread repair process has been developed for use on General Motors aluminum engine components for the above listed engines. The thread repair kits used for this process represent a significant advancement in aluminum component thread repair, providing consistently repeatable high quality repairs which, when properly performed, will meet or exceed the original specifications. This enhanced thread repair process can, and should, be used to repair aluminum engine components, instead of complete engine replacement, whenever possible. Kent-Moore has distributed these thread repair kits to General Motors dealerships as part of their essential tool packages. The J 43965 Thread Repair Extension Kit has proven to be invaluable in the repair of difficult to access thread repair locations. Listed are the Engine VINs / RPOs and the applicable Kent-Moore essential tool thread repair kits.
Consult the appropriate applicable GM Service Manual or Kent-Moore thread repair kit for complete detailed instructions on the proper use of the above thread repair kits.
For vehicles repaired under warranty, use:
Important : This Thread Repair