Originally Posted By: lonestar
Does anyone know definitively whether or not GM adds any “stuff” in their factory dino fill for break in purposes like a dose of EOS for cam break in or something like that? I purchased a car in February that was built in October 2008 and due to the fact the vehicle has basically set around outside during some fairly cold and humid weather I am anxious to get the factory fill dumped but the car has at this time under 500 miles so I do not want to dump the fill too soon if it is doctored up at all.
Cam break-in lubes are pretty much irrelevant for most modern engines because they have roller cams, not flat tappets. Even with flat tappets, the high-risk part of the break-in job is over and done with in the first 30 minutes of operation. Any assembly lubes used in the vast majority of modern engines will be straight petroleum lubes on bearings and rings, and they're harmless to leave in or to remove- your choice.
The last couple of engines I have built were flat-tappet 60s v8s, but I built them with modern rings, bearings, and pistons. The cam was coated with cam break-in lube during assembly, and I ran Castrol GTX 10w30 during the initial 2000 RPM cam run-in (30 minutes). Then I drained the oil, changed the filter, and drove the engines for about 300 miles, Changed the oil and filter again... ran until 1000 miles. Then switched to the oil I planned to use for the life of the engine (synthetic) and went to a regular OCI. No problems.
You really don't *have* to have those 300mi and 1000mi oil changes with a modern factory-assembled roller-cam engine since its not contaminated with flat tappet type cam break-in lube (which is also mildly acidic to provide the correct surface "tooth" on the hardened cam lobes), but there is zero harm in changing the oil as early as you want. In fact, I *always* do that just because its impossible to get even a factory-fresh engine block completely free of assembly debris. Its usually very small and the filter takes care of it fine, but most engine blocks are still sand-cast and there's always a risk of some silica grit staying in there through the block cleaning and assembly process. There's likely no benefit to an early dump of the factory fill, and there's a small chance that there might be a benefit.