You have just invested quite a bit of money in a New or Rebuilt engine for your vehicle. The First thing that you can do to insure your investment is to break in your engine properly. It’s a pretty simple procedure, but very, very important. When an engine is rebuilt, the process of boring and honing the cylinders leaves slight ridges on the cylinder walls to help oil adhesion. The rings wear into these ridges forming a seal. This is the primary purpose of break in.
1. Fill your cooling system with coolant and let sit for 2 hours or so with the radiator cap off. This will purge a lot of trapped air in your cooling system.
2. Install a premium oil filter. Do not use a cheap oil filter. Install a high quality 10-30 petroleum based motor oil, along with a bottle of Break In Oil Additive. The additive is included with every new or rebuilt engine purchased from EnginesUs. This additive contains zinc & phosphorous, which aids especially in the seating of the rings. It’s also great for breaking in a new camshaft. All motor oil used to have zinc and phosphorous in them. They were removed by the EPA over a period of time to reduce emissions. Do not use synthetic or semi synthetic oil during the break in period. To do so might have your piston rings never sealing.
3. Disconnect the coil wire so that the engine will not start. Crank over the engine until the oil light on your dashboard goes out. Reconnect the coil and start your engine. Let the engine idle and check for oil and coolant leaks.
4. Take the vehicle for a drive. Be gentle until the engine reaches operating temperature. The cooling system will reach operating temperature first. The oil takes about 50% longer to reach operating temperature. So if it takes 10 minutes for coolant to reach operating temperature, give the oil another 5 minutes or so.
5. Drive the vehicle for 500 miles under varying speeds and loads. Winding roads are best. Freeway driving at a constant speed is the worst.
6. Change the oil and filter at 500 miles.
7. Change your oil and filter at 3000. At this time you can switch to synthetic oil if you wish. Maintain your engine with oil and filter changes every 3,000 miles for conventional oil, or every 5,000 miles for synthetic oil.
Congratulations! You have a properly broken in new or rebuilt engine which should give you many years of reliable service if properly maintained.