batmantech Posted August 5, 2013 Share Posted August 5, 2013 Got an 06 F-350, 130,000 miles with miss. Relative compression was down 10 % Did actual check #2 150 psi all others 350 psi. Pulled head and inspect can see half circles on top of piston some small damage spots on edge also. I could see light through one of the intake valves. Pull valves one of each wobbles when rotated by hand ,clearly bent. They seem to move freely in guides now. So here is where I need some help from people that have experience with this concern. What is the proper fix? Do I get new valves for the one cylinder? Do I just clean up the others? How much can the valve seats take? Do I roll the dice and leave the piston or just replace that piston? What do you think? I put great value in everyone responses, as always, thank you! Quote Link to comment Share on other sites More sharing options...
Chad_Kelsoe Posted August 5, 2013 Share Posted August 5, 2013 Pull the lifters for that cylinder and see if the roller has failed on the intake lifter. Almost betcha the lifter is stuck in the bore. If so, I recommend at least a long block, as those rollers have likely gone through the low pressure oil pump by now. Quote Link to comment Share on other sites More sharing options...
batmantech Posted August 5, 2013 Author Share Posted August 5, 2013 All 4 lifters on that cylinder have some light scratches on the body they all came out easy, rollers on bottom seem ok. Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted August 5, 2013 Share Posted August 5, 2013 Pulled head and inspect can see half circles on top of piston some small damage spots on edge also. Do you mean that there are damaged areas on the edges of the piston crown? Is the piston crown melted? Quote Link to comment Share on other sites More sharing options...
batmantech Posted August 6, 2013 Author Share Posted August 6, 2013 There just seems to be two small areas of interest at edge of piston. Two valves made half circles, one is slight dent, and the two spots of some sort of other damage at edge. (For some reason half of my picture is getting cut off when I post it here.) Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted August 6, 2013 Share Posted August 6, 2013 Looks like it may have ingested something. Quote Link to comment Share on other sites More sharing options...
batmantech Posted August 6, 2013 Author Share Posted August 6, 2013 More info:One of the other techs remembers this truck on the lot had a miss that went away after warmed up. The truck was then sold, that was this spring. New owner drove it out from Minnesota to Yellowstone after leaving the park it started to miss ,could only feel it at idle. After back in Minnesota he decided to have it looked at. Could this be the lot rot /rusted guides that was then driven so far that it freed up now? Quote Link to comment Share on other sites More sharing options...
Matt Saunoras Posted August 7, 2013 Share Posted August 7, 2013 I would, at the very, least put lifters in that hole. There is a reason the new pushrods are shorter and I've heard several different things from different engine builders. Incorrect valvetrain geometry from the factory can cause the lifter to be fully collapsed, basically maximum preload all the time. Under a high load situation with the lifters pumped up this can cause the valves to hang open slightly. I have seen a few pics of piston to valve contact with seemingly no reason at all. Quote Link to comment Share on other sites More sharing options...
batmantech Posted August 7, 2013 Author Share Posted August 7, 2013 The thing I am struggling with is if that cylinder had pistons hit valves then what about all the others? They all are the same age ,part numbers etc. I guess the cheap fix is new valves, lifters and pushrods in that hole. Which doesn't seem right, its the old where do you stop question I guess. Quote Link to comment Share on other sites More sharing options...
lmorris Posted August 7, 2013 Share Posted August 7, 2013 That is when I would do up two estimates. One to patch that hole, including the piston Have the head sent out for inspection to a reputable machine shop as well. A second estimate to replace the engine. Let the burden fall on the owner, not you. This job is stressful enough with out having to decide how much the customer can afford. How do the cylinder walls look. If you have no ring land and can still see the cross hatch you should have no problems fixing the bad cylinder. The last 6L piston I replaced for hitting the valves, I did in chassis, including honing the cylinder, and had the head rebuilt, it is still running good. Quote Link to comment Share on other sites More sharing options...
Steve Mutter Posted August 8, 2013 Share Posted August 8, 2013 What kind of engine hone are you using and where did you get it from? Quote Link to comment Share on other sites More sharing options...
lmorris Posted August 8, 2013 Share Posted August 8, 2013 What kind of engine hone are you using and where did you get it from? FLEX-HONE GBD40018 I think we got it from our local Warehouse Services store. Should be easy enough to find. Quote Link to comment Share on other sites More sharing options...
Steve Mutter Posted August 8, 2013 Share Posted August 8, 2013 Cool,thanks Quote Link to comment Share on other sites More sharing options...
batmantech Posted August 13, 2013 Author Share Posted August 13, 2013 Update: Customer gave the go head to send out head and new valves, lifters on that hole. He also wanted the new piston. Quote Link to comment Share on other sites More sharing options...
batmantech Posted August 22, 2013 Author Share Posted August 22, 2013 Well put in the new piston, lifters, and pushrods on that cylinder. Sent out the head, 4 new valves. Been up and running a couple days so far everything is o.k. Thanks again for the input. Quote Link to comment Share on other sites More sharing options...
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