Test Run and Break-In of Engine After Overhaul

PROCEDURE


When starting the engine for the first time after completing its overhaul, always keep a Class B fire extinguisher at hand!
1. After installing the powertrain in the vehicle, check the engine oil and coolant levels.
2. With the spark plugs removed and the ignition system temporarily disabled (see Engine Compression Test), crank the engine until the oil pressure is built up sufficiently for the oil pressure warning lamp on the instrument panel to illuminate.
3. Install the spark plugs, connect the high-tension leads and restore the ignition system.
4. Start the engine. Starting may be slightly delayed while fuel pressure builds up, but no particular difficulties should occur.

If backfiring occurs in the throttle body, check the ignition timing and valve timing.
5. After starting, warm the engine to normal operating temperature, checking for signs of oil and coolant leaks during warm-up. Let the engine idle for 15 minutes, which is especially important after replacing the connecting rod bearings.
6. Stop the engine and check the oil and coolant levels again.
7. Now you can proceed with the road test and break-in. Drive the vehicle to an area with minimal traffic and accelerate briskly to a speed of 50 ÷ 80 km/h. Then decelerate to 50 km/h by fully closing the throttle. Repeat this procedure 10 to 12 times; the cyclic loads help the piston rings seat against the cylinder walls. Check the engine for leaks again.
8. For the first 800 km (500 miles), operate the engine gently and check the engine oil level regularly and frequently. Increased oil consumption during the break-in period is normal.
9. At approximately 800 ÷ 1 000 km (500 ÷ 600 miles), replace the engine oil and oil filter.
10. For the next several hundred kilometers, the vehicle can be operated under normal conditions.
11. At 3200 km (2000 miles), replace the engine oil and oil filter again. The engine can now be considered fully broken in.