Under What Circumstances Should the Four-Matching Parts Be Replaced?
3 Answers
The four-matching parts should be replaced under the following circumstances: 1. Engine Overload: The higher the engine speed and the greater the load, the more mixed gas will enter the crankcase, which can easily cause the oil-gas separator to overload and fail. 2. Excessive Clearance: The valve guide and valve clearance in the cylinder head are too large (especially when using a butterfly valve brake). 3. Air Compressor Blow-by: Blow-by in the air compressor is caused by wear of the air compressor piston rings. Blocked air output from the air compressor leads to blow-by, such as clogged air compressor outlet pipes or a blocked dryer tank. As the vehicle ages, the clearance values in various parts will increase, making such situations more likely to occur.
After driving for so many years, I've concluded that replacing the four major engine components is mainly necessary when serious engine problems arise: for instance, when the car burns oil excessively, with blue smoke billowing from the exhaust pipe like a chimney; or when the car feels powerless and struggles to climb hills; or when fuel consumption suddenly spikes, doubling the usual amount. These are all signs that the piston rings or cylinder liners are worn out. Additionally, if an old car with over a hundred thousand kilometers on the odometer shows insufficient cylinder pressure or abnormal noises during inspection, a full set replacement is often recommended during repairs. After replacement, the engine runs quietly and smoothly, with restored performance. I think regular inspections are crucial, especially for friends who frequently drive long distances—don't wait until you're stranded on the road to regret it. Using high-quality engine oil during regular maintenance can delay the need for replacement.
As an average car owner, from a daily driving perspective, the timing for replacing the four-piece engine kit depends on engine performance: a noticeable drop in power makes acceleration sluggish; unexplained increase in fuel consumption; clicking sounds at startup or shaking during acceleration. These are all signs to check—if piston rings or connecting rod bearings are worn out and not replaced, it could lead to complete engine failure. Generally, vehicles with over 150,000 kilometers should be monitored closely; replacement costs a few thousand, but the car feels reborn afterward—smoother handling and reduced fuel consumption. It's wise to make a habit of regularly checking engine condition to save money and avoid major breakdowns.
