Engine Overview and Common Failures
The weight of the VAZ 21126 engine according to the catalog is 115 kg. The most common problem is fluctuating engine speed due to a faulty idle air control valve. However, sometimes the culprit is a dirty throttle body or idle air control regulator. Overheating is a frequent issue, with the thermostat often failing. If you struggle to warm up in winter or constantly overheat in summer, start by checking the thermostat. Electrical problems are also common, especially with the starter, ignition coils, fuel pressure regulator, and ECU 1411020. Clogged injectors often cause engine misfire. If the spark plugs and coils are fine, it's likely the injectors. Cleaning them usually helps. Timing belt failure is a major concern. The recommended replacement interval for the timing belt kit is 180,000 km, while the tensioner pulleys might not last that long. The water pump is typically replaced at 90,000 km, which is also quite optimistic. Any failure in these components can result in belt breakage, leading to valve damage. Update: Since July 2018, the engine has been updated with piston rings without grooves. Knocking noises under the hood are often caused by hydraulic lifters, but if they are fine, it may indicate worn connecting rods or pistons. Be prepared for a major repair.