wewille Posted April 17, 2015 Share Posted April 17, 2015 Hey guys, i think i have a good one! Back in December this 2006 f-250 rolled in with a complaint of a tea kettle noise. Tested oil cooler, head gaskets, fan clutch, etc... Anyways replaced head gaskets, sent heads to machine shop they found cracks and replaced the castings. Reinstalled with ARP's, oil cooler etc. Shipped it. About 2 weeks ago and about 5,000 miles since the repair it rolls back in losing coolant out degas bottle. Pulled heads sent to machinist, he found a cracked glow plug tube. He got us another head and my apprentice reassembled the engine. Got it running, just to find the battery light on and no alternator output. Installed a new alternator. Then it started to crank funny all of a sudden. Still ran great no misfires plenty of power. Checked the starting circuitry, and batteries all good. So a starter was installed. Now it cranks great. Fast forward again and the truck is back with a concern of a very light haze of white smoke. No codes, runs great, starts great. Cylinder contribution shows 2 and 4 ever so slightly down, with 3 a bit up. Enhance power balance makes it worse, but not bad. Relative compression test sometimes displays 4 as 6% low, sometimes 2% and sometimes other cylinders will be slightly low, but usually number 4. Manual compression test was started today, but due to some gauge problems i was unable to complete testing until hopefully tomorrow. Anyways my question to you guys is it possible to have injector number 3 slightly over fuel to cause cylinder number 4 to be low on a relative compression test? Obviously that could be the cause of the white smoke. Cancelling number three does not reduce the white smoke which i think is odd, and neither does cancelling 4. I would think if cylinder 4 truly had low compression canceling that injector would eliminate the smoke. Truck Has about 117,000 miles. The last 20,000 of which the customer has a had a sct tuner in it. He does not tow, or offroad, but it is it street toy. I understand the consequences of a tuner, regardless the customer wont permanently take it out. Hopefully I'm not missing any of the story! Thanks in advance! In the relative compression test picture cylinder number two is almost always ok, not sure why i took a picture the only time it was slightly low. I'm also thinking about moving injector number three just to see how it affects relative compression after i finish the manual compression test. Quote Link to comment Share on other sites More sharing options...
Matt Saunoras Posted April 17, 2015 Share Posted April 17, 2015 I had a truck last year that had a crank trigger wheel that came loose and cause the most bizarre power balance I've ever seen. It started and ran okay but had a shake to the engine that was definitely not a misfire. If it is sitting there running a smooth line but not all contributing evenly I probably wouldn't think injectors right away. I don't really know though about your situation. Its a lot of work but I've swapped injectors before just to cover my ass before I say for sure this thing needs injectors. Yes they fail a lot in a 6.0 but if something doesn't seem right it probably isn't. Quote Link to comment Share on other sites More sharing options...
wewille Posted April 17, 2015 Author Share Posted April 17, 2015 Hey Matt, i do appreciate the response. At the moment we are hunting down the snapon guy to see if he can swap out my compression guage. In the mean time i do believe im going to move that number three injector. Im doing another headgasket job in the next bay, so once i get those injectors out i may just put one in the other truck. At least save a oring kit! When you had the loose tone wheel I'm assuming the power balance was not consistent at all? Did that one have a slight white haze? This thing has a slight haze that burns your eyes, definitely unburnt fuel. Hopefully not compression. Even at that the worst i can think of would be a bent push rod or something. Cylinders and pistons looked great both times the heads were off, couldn't imagine a bent connecting rod, its not a 6.4. Quote Link to comment Share on other sites More sharing options...
Matt Saunoras Posted April 17, 2015 Share Posted April 17, 2015 Not sure about the haze but the truck did have an up and down power balance similar to what you posted. Definitely get the compression gauge on it though. No personal experience but I have heard nightmare stories about aftermarket cylinder head castings cracking on places you wouldn't expect a 6.0 head to crack. The aftermarket castings are usually rougher around the edges and won't have any numbers stamped in the web around the valve train. That's the best way to identify them Quote Link to comment Share on other sites More sharing options...
forddieseldoctor Posted April 18, 2015 Share Posted April 18, 2015 Manual compression for sure. As Matt said a loose crank ring can do wierd stuff. If it was in my hands I would do the diesel cam timing test to see if everything is right. I had one that would buck if and when it wanted to. Cam timing test showed crank a half tooth off of crank. Quote Link to comment Share on other sites More sharing options...
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