IMS bearing again

[judibake]

Two years ago I traded my 2001 C2 (125000 km) for a 2003 C4 with tiptronic (120000 km). Neither have had the IMS bearing replaced. I've read TOO much about the bearing experience. Last fall I changed the oil and filter and adjusted the level after using the car on several occasions. The oil level registered just at the full capacity electronically and manually. The car was then stored for 4 months when I checked the oil before restarting. It was 1 quart down, so I added a quart and it has remained just under full. There are no signs of oil leaks and the anti freeze is clean. Any explanation for the loss of the quart?

This got me thinking about oil and lubrication and possible relation to failure of the IMS bearing. I assume that the proper oil level is necessary to provide adequate lubrication for the engine but does the proper oil level truly reflect the ability of the oil to lubricate the IMS bearing? I don't know the mechanism for its lubrication but could it possibly be enhanced by adding an extra 1/2 to 1 quart of oil?

There are varying opinions about overfilling I quart. Is there any rationale to this suggestion?

[JFP in PA]

3 hours ago, judibake said:

Two years ago I traded my 2001 C2 (125000 km) for a 2003 C4 with tiptronic (120000 km). Neither have had the IMS bearing replaced. I've read TOO much about the bearing experience. Last fall I changed the oil and filter and adjusted the level after using the car on several occasions. The oil level registered just at the full capacity electronically and manually. The car was then stored for 4 months when I checked the oil before restarting. It was 1 quart down, so I added a quart and it has remained just under full. There are no signs of oil leaks and the anti freeze is clean. Any explanation for the loss of the quart?

This got me thinking about oil and lubrication and possible relation to failure of the IMS bearing. I assume that the proper oil level is necessary to provide adequate lubrication for the engine but does the proper oil level truly reflect the ability of the oil to lubricate the IMS bearing? I don't know the mechanism for its lubrication but could it possibly be enhanced by adding an extra 1/2 to 1 quart of oil?

There are varying opinions about overfilling I quart. Is there any rationale to this suggestion?

 

First of all, over filling these cars, regardless of the IMS bearing, is a bad idea.  When the system is over filled, you only know it is over, but not by how much.  It could be 1/2 quart, or three quarts, the display will say the same thing.  With IMS bearings capable of exterior lubrication, such as the LN ceramic hybrid, do so using the oil mist inside the rear case area; the level of he oil is irrelevant to this process.  What is actually more important to the IMS is how fresh the oil is and how much ZDDP it contains.

 

A couple on notes in passing: The factory IMS bearing does not lubricate properly regardless of the oil level as it is not designed to allow outside oil in, so again the oil level is irrelevant.  Second, you should not put your car away for the winter with used oil in it.  Used oil typically carries both fuel and water in it, which accelerates the oil break down and can even lead to internal componet corrosion.  Put it away with fresh oil in it.