Mekanik Posted February 4, 2014 Share Posted February 4, 2014 I'm working on a 2005 F250 with a 6.0L. Two weeks ago it had a broken rocker arm for cylinder #2 exhaust valve, along with a bent pushrod. I checked my lifter travel with a long 1/4" extensionI, and then I replaced the bent pushrod and the rocker arm without any problems. I cranked the engine several revolutions to make sure my valvetrain was working properly and I didn't have any problems. After I got it put back together it ran great on the road test. One week later the truck is back with similar symptoms. I removed the left valve cover and oil rail and the #2 exhaust pushrod is bent again. The rocker arm is still attached to the fulcrum so I really don't understand how the push rod would just bend. Has anyone also run into the same problem on a 6.0L? For the record I did replace headgaskets about 3000 miles ago. The truck is heavily modified with a programmer, EGR delete, and adjustable fuel pressure regulator. Not that it matters but the current owner bought it that way and claims to drive it very gently. When I did the headgaskets I lowered the fuel pressure to factory specs. Quote Link to comment Share on other sites More sharing options...
Chad_Kelsoe Posted February 4, 2014 Share Posted February 4, 2014 Sounds like a lifter sticking in the block to me.... Quote Link to comment Share on other sites More sharing options...
Mekanik Posted February 4, 2014 Author Share Posted February 4, 2014 I checked it again today with a long 1/4" extension and it moves up and down with the engine cranking. Quote Link to comment Share on other sites More sharing options...
Brad Clayton Posted February 4, 2014 Share Posted February 4, 2014 I was going to mention an exhaust valve sticking/binding in the head, kinda like the lot rot syndrome, but it sounds like this truck gets driven regularly. Quote Link to comment Share on other sites More sharing options...
ktmlew Posted February 4, 2014 Share Posted February 4, 2014 I was going to mention an exhaust valve sticking/binding in the head, kinda like the lot rot syndrome, but it sounds like this truck gets driven regularly. I would still look hard at this possibility. Quote Link to comment Share on other sites More sharing options...
Aaron Posted February 4, 2014 Share Posted February 4, 2014 Got any codes? He might be revving the piss out of this thing and causing valve float. Also worthy of note, the exhaust valves can creep open with excessive EBP which may be a by product of the tuning and not running a waste gate and high amounts or boost. The 6.0 will help valves close every time. Lol. I would expect it to bust up the rocker arm as well, but wherever the weakest link is would be the result I suppose. Are you changing the whole rocker assembly or just the rocker arm and clip? I had one that the mount that bolts to the head was just wrecked underneath from the rocker arm bouncing off of it. Quote Link to comment Share on other sites More sharing options...
Matt Saunoras Posted February 5, 2014 Share Posted February 5, 2014 I have seen one that had no driveability symptoms but the truck bent 2 pushrods on the same hole before the head was removed and a smashed up piston was found. Someone along the line replaced a fuel injector with a blown off nozzle and never thought to wonder where the piece went. Quote Link to comment Share on other sites More sharing options...
DieselD Posted February 5, 2014 Share Posted February 5, 2014 Got any codes? He might be revving the piss out of this thing and causing valve float.Also worthy of note, the exhaust valves can creep open with excessive EBP which may be a by product of the tuning and not running a waste gate and high amounts or boost.The 6.0 will help valves close every time. Lol.I would expect it to bust up the rocker arm as well, but wherever the weakest link is would be the result I suppose.Are you changing the whole rocker assembly or just the rocker arm and clip? I had one that the mount that bolts to the head was just wrecked underneath from the rocker arm bouncing off of it. This is along the lines I am thinking of as well as soon as a tuner was mentioned. Alot of tuners raise the rev limiter on the programs Quote Link to comment Share on other sites More sharing options...
Mekanik Posted February 5, 2014 Author Share Posted February 5, 2014 I removed the exhaust valve springs with the intention of swapping #2 valves with #4 valves to see if it's the guides or the valves and I can't even remove the #2 exhaust valves. I had to tap them with a hammer just to get them to move. I don't see any point in removing them from the head at this point because this is definately my smoking gun. Got any codes? He might be revving the piss out of this thing and causing valve float.Also worthy of note, the exhaust valves can creep open with excessive EBP which may be a by product of the tuning and not running a waste gate and high amounts or boost.The 6.0 will help valves close every time. Lol.I would expect it to bust up the rocker arm as well, but wherever the weakest link is would be the result I suppose.Are you changing the whole rocker assembly or just the rocker arm and clip? I had one that the mount that bolts to the head was just wrecked underneath from the rocker arm bouncing off of it. That's interesting. I did just replace the rocker and clip. It would probably have been easier to replace the entire rocker, but I was afraid to didsurb the headgasket by removing a head bolt. I have seen one that had no driveability symptoms but the truck bent 2 pushrods on the same hole before the head was removed and a smashed up piston was found. Someone along the line replaced a fuel injector with a blown off nozzle and never thought to wonder where the piece went. I saw this in a 7.3L where someone managed to replace lifters without removing the heads and then as a bonus left behind parts of the old push rod and lifter. Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted February 5, 2014 Share Posted February 5, 2014 There are transmission valve body hones you can buy that fit into the valve guides and clean them up nicely. I developed that trick back when i used to see seized valves on the 7.3L... 6.0L and one 6.4. Saved every head. Slap a new valve in it and it's good to go! Quote Link to comment Share on other sites More sharing options...
Mekanik Posted February 5, 2014 Author Share Posted February 5, 2014 There are transmission valve body hones you can buy that fit into the valve guides and clean them up nicely. I developed that trick back when i used to see seized valves on the 7.3L... 6.0L and one 6.4. Saved every head. Slap a new valve in it and it's good to go! Keith, I don't think I want the liability of repairing the head. You've done it though? Have you ever had any problems doing it? Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted February 5, 2014 Share Posted February 5, 2014 Six times is the number that sticks in my mind. One truck had two stuck valves coming off of the carrier when new. Any way all of the trucks I did this to were permanently fixed to the best of my knowledge. Quote Link to comment Share on other sites More sharing options...
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