I had a truck brought in on a hook yesterday afternoon with a failure I haven't seen before. I hope
someone can shed some light on it. 2015 KW isx15 2350. Driver said engine quit and won't start.
I had the driver crank it over and it made a grinding sound in the front of the engine. I took the valve
cover off and found the #2 intake rocker broke in half and the #5 exhaust adjuster and valve bridge
were broke. That didn't explain the grinding sound. The driver cranked it over crankshaft turned
camshaft didn't. I took the front cover off and the upper idler gear fell out. No damage to the four bolts.
I remover the broken parts, set the crankshaft to insert pin and I did and inserted a #6 wedge in the
camshaft. I put another idler gear in and set the lash at .004. Removed pin and wedge and barred the engine until the rear rocker assy. sat flush with the head. Torqued front bolt with the round spacer to 22ftlb plus 60 degrees. Barred the engine until the front rocker assy. sat flush and torqued the bolts the same as the rear. Barred the engine to A with both #1 rockers loose and adjusted the lash, .014 on the intake (long rocker) and .027 on the exhaust. The adjusters don't look right. I barred the engine to B and adjusted #5. The top of the adjusters are flush or below the top of the jam nut. Before I removed the rocker assy. the adjusters were 2 to 4 threads above the top of the jam nuts. Why are the adjusters so far off. What did I miss. Any thoughts ?
Valve adjustment issue
Discussion in 'Heavy Duty Diesel Truck Mechanics Forum' started by rustymike, Dec 19, 2021.
-
-
Trucking Jobs in 30 seconds
Every month 400 people find a job with the help of TruckersReport.
-
Valves hit the piston when the idler gear fell out. Thats why the rocker was broke. Need to pull the head off and also inspect pistons.
Roger McG, jamespmack, OLDSKOOLERnWV and 6 others Thank this. -
Bet some valves kissed pistons when the cam stopped turning. That would explain the busted rocker and and bridge.
Probably some major carnage under the head.little cat 500, Roger McG, jamespmack and 3 others Thank this. -
jamespmack Thanks this.
-
If it smashed up the valves/pistons some debris may have also ran through the turbo and damaged it. The exhuast housing will have to get removed to verify. Looking through the turbo outlet is not good enough.
Injector tips may also have debris damage.
How many miles on the engineOxbow, jamespmack and AModelCat Thank this. -
Had one of these about a year back, same exact deal- gear fell off. Customer said that nobody had ever been in the engine since berth. Got by with just a head and the broken rockers and bridges, of course the idler gear, mount and bolts.
Oxbow, jamespmack, OLDSKOOLERnWV and 2 others Thank this. -
Engine has 400,000 on it. I put the valve cover and EGR crossover tube back on, covered the turbo and rolled it outside
until we find another engine. I have a john deere loader in the shop with a rod sticking out of the block waiting for a engine a volvo
loader with a broken engine and another truck waiting for a engine. And I was hired to do the easy stuff, A and B services,
clutches, brakes and aftertreatment problems. Aftertreatment not so easy. Also, what does the little eyeball stand for next to the word replies ?Last edited: Dec 21, 2021
jamespmack Thanks this. -
About my valve adjustment issues. I took the cylinder head off last night and found nothing, absolutely nothing. No damage to the pistons or the
valves. The valves are not bent, move freely and are not stuck open. Camshaft looks good, no pitting or groves in any of the lobes.
Ill keep digging.
Trucking Jobs in 30 seconds
Every month 400 people find a job with the help of TruckersReport.