Two cases of 2021 - diesel engine malfunction
03 -
04 xiao automatically shut down 1 Volvo EC240BLC type excavator after routine maintenance, commissioning walk 20 m that appear when automatic flameout fault.
The check engine appearance, no exceptions.
Start again, found that the starting resistance is bigger, judge holding shaft engine connecting rod is suspected.
Remove the oil pan, found that part of the connecting rod strain.
Repair the injury of the connecting rod, on-site commissioning, oil pump suction and discharge of oil flow and check other parts without exception, but the engine is unable to continue normal operation.
After commissioning, inspection, have been found no substantial reason, overhauling found a connecting rod and strain again.
Finally, Volvo's technology personnel according to the oil filter bracket shell casting arrows point to the surface, concluded that the oil filter bracket Ann inverse.
Memories by the maintenance personnel, due to remove the difficulties in the replacement of oil filter, at that time, had to oil filter is removed, along with stents with vice clamping to remove the oil filter.
Oil filter bracket installation direction are interchangeable, because there is no attention to its equipped with one-way valve when installed, not according to oil filter bracket shell surface casting arrow pointing to install, you will be the oil filter bracket installed backwards.
Check valve position after installation errors, make oil road impassability, lead to tile burning engine shaft and automatically shut down.
Repair crankshaft, replace the crankshaft and connecting rod, correct installation oil filter bracket and start of commissioning, the machine working normally.
Coolant flow into the sump 1 CLG888 loader in hvac water pipe burst, found after about 15 l water supplement.
Trial found that under the engine exhaust is very large.
Stop check engine normal appearance, remove the oil cap found covered with water, check the oil level height is beyond oil feet online about 25 mm, suggests the coolant flow into the oil sump.
Discharge of oil when the first out about 5 l clear cooling fluid.
Remove the cylinder cover inspection, found that V engine cylinder present circular serious injury (
Overheating short time usually takes a local strain, circumferential strain in general because overheating) for a long time
。
Remove the V cylinder piston, found that the piston skirt serious injury, the outer wall of cylinder jacket water leak is severe, but the connecting rod and connecting rod without exception.
Remove the V cylinder piston cooling nozzles inspection, found in 1 oil cooling nozzle passage about 20 mm long and 5 mm diameter seal broken section of the broken section just inserted within the oil duct, blocked the V cylinder piston cooling nozzles of oil way.
Remove the V check cylinder liner, cylinder seals have been found by high temperature erosion, local seal ring groove for high temperature blue.
To further examine other cylinder seals for the high temperature erosion, remove the adjacent VI check cylinder liner, the liner and the sealing ring has no exception.
Analyse the causes of failure are as follows: in the maintenance of oil change the oil filter, its sealing ring is not placed in the ring groove back, or oil filter factory seal not installed, install a filter when he will seal crowded broken, then the section enter into engine oil, stranded in the V at the entrance of the oil cylinder piston cooling nozzle, plug the oil way.
Because the V cylinder piston can not get effective cooling (
Only on the oil spray cooling is not enough)
, causing the piston and the piston skirt, the cylinder liner and piston is circumferential strain.
When V cylinder, cylinder engine fault, cylinder liner surface roughness is destroyed, the piston and cylinder liner friction occurs after high temperature, the cylinder jacket seal ablation.
After sealing ring damage, coolant flow into the sump.
Corresponding maintenance of cylinder liner, piston and processing, replace oil filter and jacket ring refitted after commissioning, the engine back to normal.
(
Source: engineering machinery and maintenance)
