My sister has a friend that has a Northstar that is going through oil at a unreal rate. Like a quart every 500 to 600 miles I remember a month or two ago a thread that was running on this problem. I did three different searches and could not find that particular post. The one I'm looking for had something about Cadillac would replace the motor if the customer pushed the point. Any help would be appreciated thanks.
Thanks guys for looking for me I found something simular over a GMForums.com. Someone posted TSB for the problem. Here is the TSB for anyone that is interested.
It says this:
Engine - Higher Than Expected Oil Consumption
File In Section: 06 - Engine/Propulsion System
Bulletin No.: 02-06-01-009
Date: March, 2002
Higher than Expected Oil Consumption
(Clean Piston Rings)
1996-1999 Cadillac Concours, Deville, Eldorado, and Seville with 4.6L Engine (VINs Y, 9 - RPOs LD8, L37)
Some customers may comment on higher than expected oil consumption. The typical customer with this condition comments on consumption in the range of 0.946 L (1 qt) of oil used in 1600-2250 km (1000-1400 miles) of operation. The oil consumption rate and possible oil consumption areas, as per Corporate Bulletin # 01-06-01-011 dated March, 2001, should be verified prior to performing the ring cleaning procedure below. The standard for acceptable oil economy and the method for determining oil economy are outlined in Corporate Bulletin # 01-06-01-011.
The following text is referenced from Corporate Bulletin # 01-06-01-011 for your convenience.
The accepted rate of oil consumption for engines used in the vehicles referenced is 0.946 L (1 qt) in 3200 km (2000 mi). This rate only applies to personal use vehicles, under warranty, maintained in accordance with the appropriate maintenance schedule, with less than 58,000 km (36,000 mi), or 80,450 km (50,000 mi) for Cadillac, driven at legal speeds in an unloaded (for trucks) condition.
Although there are several reasons for less than expected oil economy described in Corporate Bulletin # 01-06-01-011, one area not covered is reduced sealing ability of the rings. Through normal usage, combustion chamber deposits may build up to the point that the movement of the rings could become restricted and prevent the rings from wiping all of the oil off the cylinder walls and allowing it to be burned in the combustion process.
A new ring cleaning process has been developed to restore the function of the rings. Once the possible oil consumption areas in Corporate Bulletin # 01-06-01-011 have been eliminated, this cleaning process should be preformed.
Important :It is critical in this cleaning process that the piston and ring cleaner remain in the cylinders for a minimum of two hours to fully clean the components. The cleaner solution must be removed before three hours. Additional soak time does not increase the effectiveness of this process. If solution with the dissolved deposits remains in the cylinder too long, it will soak back into the rings and cause them to stick again. If this happens, the oil economy will be reduced even further.
An oil economy test should be performed after the cleaning process is completed. Before starting this test, the full oil level on the dip stick should be noted and shown to the customer. The correct oil fill is 7.1L (7 1/2 qts) with a filter. The dipstick should not be read for least 15 minutes after the engine has been shut off for an accurate reading. Typically, the oil level shown on the dipstick is in the second or third section above the add mark. If the indicated oil level is at the MAX mark, there is approximately 0.47L (1/2 qt) too much in the system and it will be scavenged by the PCV system quickly. When performing this test, the most accurate results may be obtained by having the customer drive the vehicle until the CHECK OIL LEVEL message appears and then returning the vehicle to the dealership to determine the oil economy. No damage will be done to the engine by operating it until the Check Engine Oil Level message is displayed. There is over 5.68L (6 qts) of oil still in the system.
Parts are currently available from GMSPO.
For vehicles repaired under warranty, use the table.