What Causes Excessive Exhaust Without Burning Engine Oil?
1 Answers
It is most likely caused by excessive piston ring clearance generating exhaust gases. Valve stem seals do not produce this kind of exhaust, and excessive valve guide clearance can also lead to this phenomenon, although such faults are rare. The main causes are still related to pistons and piston rings. Below are detailed explanations: 1. Wear of engine piston rings: Severe wear of engine piston rings and cylinder liners, piston top erosion, or cylinder scoring. If piston rings and cylinder liners are severely worn, or if there is piston top erosion or cylinder scoring, the seal between piston rings and cylinder liners becomes loose. During the compression and expansion processes of the diesel engine, a large amount of compressed gas enters the crankcase through the tiny gaps between piston rings and cylinder liners, leading to increased crankcase exhaust pressure. The main symptoms include severe exhaust from the breather, insufficient engine power, and possibly blue smoke. 2. Incorrect installation of engine piston rings: If piston rings are installed incorrectly with all gaps aligned, even if the piston rings are not worn, a large amount of high-pressure gas from the compression and expansion processes will enter the crankcase, causing increased crankcase exhaust pressure.
