After an engine rebuild, running-in your rebuilt engine correctly is essential for long-term performance and reliability. But exactly how long should a rebuilt engine be run-in? What oil do you use during the run-in period? And what mistakes should you definitely avoid during the run-in of your engine block?
At Van Thiel Motor Revision We recommend a careful running-in process with the right running-in oil to prevent damage to piston rings, cylinder walls and bearings.
Running-in a Remanufactured Engine - Getting it Right
After a engine revision running-in the rebuilt engine is a crucial step to ensure long-term performance and reliability. A correctly run-in engine prevents premature wear, extends the life of the engine block and ensures optimum lubrication of all moving parts.
On this page, we explain how to run in a reconditioned engine, which mistakes to avoid, and why breaking in the engine after overhaul essential for a good end result.
Why is running-in a rebuilt engine important?
In an engine overhaul, many parts are renewed or reworked - such as piston rings, cylinder walls, bearings and valves. These parts need time to bed in properly. By running the engine in correctly:
Prevents excessive wear on piston rings, cylinder walls and bearings
Ensures better sealing and compression
Extend the service life of the overhauled engine
Optimises long-term fuel consumption and power
Running-in procedure for a rebuilt engine
1. Use the right running-in oil
During the first 500-1,000 kilometres, use a special run-in oil or mineral engine oil without additives (this applies to certain types of engines). This oil allows the parts to wear in properly without excessive slipperiness.
2. Avoid high speeds and loads
Allow the engine to warm up slowly. During the run-in period:
Do not let it idle for long periods of time
Not above 3,000-3,500 rpm
No full throttle or abrupt acceleration
3. Alternate loading
Vary speeds and loads to promote an even run-in. Alternate short trips, city driving and light motorway driving.
4. First oil and filter change
After about 1,000 kilometres, it is important to change the running-in oil and oil filter. These may contain metal particles released during running-in.
5. Check for leaks and noises
During the run-in period, it is wise to check regularly for:
Oil leaks
Coolant level
Abnormal noises or smoke
Common mistakes when running in a rebuilt engine
High load too quickly (especially on turbo engines)
Using the wrong or too smooth synthetic oil
Do not use run-in oil
Engine idling for long periods
No oil changes after the run-in period
How long does a rebuilt engine need to run in?
On average, the run-in period lasts between 1,000 and 1,500 kilometres. This can vary by engine type and application (e.g. diesel engines, petrol engines or turbo engines).