Engine Overview and Common Failures
The weight of the 4S-FE engine according to the catalog is 140 kg. The engine number is located at the junction of the block and the gearbox. Like the 2-liter 3S engines, this unit suffered from poor connecting rod bolts. At high revs, the connecting rod would break and the infamous "friendship fist" would appear. Interestingly, engines from the last years of production were more susceptible to this problem.
Timing belt breakage: Besides the camshaft, the timing belt also drives the water pump and oil pump, so there are many reasons for it to break. The advantage here is that the valves do not bend.
Oil consumption: On mileage over 200,000 km, oil consumption often occurs due to ring sticking. If you postpone the overhaul, it can reach very significant levels.
Minor breakdowns: Like any old engine, there are enough minor problems here: oil leaks occur, sensors malfunction and fail, especially the idle control valve and lambda sensors, the ignition system malfunctions, and the power unit supports wear out very quickly. Since there are no hydraulic compensators here, the valves need to be adjusted every 100,000 km.