How to Determine if a Diesel Engine Has Cylinder Scoring?

[VonRichard]

Cylinder scoring judgment: abnormal noise, lack of power, exhaust gas, also known as blow-by, increased fuel consumption, difficulty starting after shutdown. Below is an introduction to the causes of cylinder scoring: (1) Poor cylinder lubrication: Insufficient or interrupted supply of cylinder lubricating oil leads to direct metal contact and cylinder scoring. Reasons for poor cylinder lubrication include: too little oil in the oil pan or poor oil quality, excessively high diesel engine temperature, or damage or failure of piston rings (mainly oil rings). (2) Inadequate running-in: To achieve effective running-in in the shortest possible time, the duration of running-in and load distribution must be considered. Running-in at too low a load for an extended period may not complete the process, while rushing into high-load operation can cause cylinder scoring. Therefore, during the diesel engine running-in period, the following should be noted: appropriately increase the oil injection amount; after replacing piston rings, operate under low load for a period; after replacing pistons and cylinder liners, run them in before increasing the load.

[HadleyFitz]

I've been driving diesel cars for many years. The most common way to identify cylinder scoring is by listening to the engine noise—it produces a sharp knocking sound, especially noticeable during acceleration, like metal scraping. I've experienced it myself; that time, it was accompanied by a severe loss of power, making it difficult to climb hills, as if the car had lost half its vitality. Another key sign is blue or black smoke from the exhaust pipe, because when the cylinder walls are damaged, engine oil seeps in and burns, causing abnormal smoke color. Oil consumption also speeds up—if you notice the oil gauge dropping rapidly, it's a red flag. Oh, and if the engine shakes violently or has difficulty starting, especially when cold, that's also a sign of cylinder scoring. My advice is not to keep driving if you notice these symptoms. Get it checked by a professional shop for cylinder compression—if the reading is below the normal range, it's basically confirmed. Otherwise, continuing to drive could ruin the engine.

[VonAllison]

As someone who frequently tinkers with diesel engines, I'll cut straight to the quick diagnostic tricks. The fastest method is listening carefully to the engine sound after startup - if you hear abnormal knocking or tapping noises, it likely indicates piston rings have scored the cylinder walls. Visually, pay attention to exhaust pipe emissions; blue smoke often appears when cylinders are scored, caused by burning engine oil. Monitor oil consumption too - if freshly added oil depletes rapidly without much driving, lubrication issues may exist. Performance-wise, you'll notice sluggish throttle response, inability to reach normal RPMs, as if something's obstructed. Another telltale sign: excessive vibration during cold starts signals internal damage. For testing, if accessible, use a compression gauge - cylinder pressure below 8-10 MPa basically confirms cylinder scoring. Remember, early detection saves repair costs; don't delay until major overhaul becomes necessary.

[ValerieAnn]

When I first started learning to drive, I encountered diesel engine cylinder scoring. It's not that complicated to diagnose. First, listen for engine noise – if there's a knocking sound, be cautious, especially when idling as it becomes particularly harsh. Then check the exhaust smoke color – if it turns blue or black, that's a warning sign indicating abnormal oil combustion. I noticed significantly reduced power, with sluggish acceleration even on flat roads, as if carrying extra weight. Rapid oil consumption is another red flag – the low oil warning would come on just one or two weeks after maintenance. Simply put, if you experience hard starts or excessive vibration, it's almost certainly the issue.