I have a 2005 6.0 4x4 with 153000 miles on her. About 3 weeks ago it ran low on diesel (not out) and started running real rough. Put some diesel in the tank and after about 2 minutes of rough idle it smoothed out and started running fine. The truck hasnt really been driven much since then but when it would be cranked up it would start smoking a grayish smoke but had a strong diesel smell to it but otherwise run fine, no rough idle, no hesitant starting. Well I changed the oil today from 15w40 to T5 10w30 and since it hasnt been driven much lately decided to take her down the road. Wasnt ******* on her but was letting the turbo get up to full boost. Well almost home and started running rough (smoke had just about cleared up) and there was a loud knocking sound coming from the drivers side. When I parked the idle was rough and the rpms were surging up and down. Came inside and started googling the knock to see if maybe it was an injector or maybe a rod. Went back out and was going to start it up and record the knock and it would not turn over. It was like it started to turn over but kind of jumped or bounced and would not do anything else. I have a generic code reader and have no codes. Could it have been an injector knocking or one that had been leaking down causing the smoke over the few weeks and then me blowing it out causing it to stick wide open and knock and then filling up with fuel? Thanks for the help.

 

1st. I would do is visually check the degas bottle for coolant fill, then I would pull the EGR valve and look for gunked up wetness. It could of hydrolocked from coolant getting into the cylinder through the EGR.

 

check 2006powerstoke he had a hydrolock problem and cheezit gave him a few things to try to test it

 

Degas bottle is full. Dont think it is the egr cooler.

 

Bad injector,pull the glow plugs slowly crank the motor and drain the cylinders.The wet GP will giveaway the bad injector.

 

Will a bad injector sound like a rod knocking? It had a pretty loud knock when I pulled in the driveway. We have had an issue with it not starting after it warmed up. When we bought it the dealership had put in 10w30 and I changed the oil on my own to 15w40 after about 1500 miles just to have my own records of it. Thats when we had the hard start issue. Always cranked and ran the first time but you better not kill it afterwards or you would have to wait on it to cool down. I was leaning toward a hpop leak or o-ring but never had power loss issues or it dying like some of the symptoms of that I have seen. I came across some threads about oil and thats why I went back to the 10w30. Was just trying it out and driving it since it hasnt been out of the yard since we ran it low of diesel a few weeks back. It had around 60 miles to go on the fuel gage when the low fuel light came on and it immediately started missing. A day or so later my wife was going to go the the country store right down the road but it was running real rough so she killed it. I put 10 gallons of diesel in it and let it run and that smoothed out. A day or so later is when we noticed the smoke issue but no rough idle or anything, just smoke but we still didnt want to drive it til I knew what exactly was wrong with it. I just took it down the road a couple miles and turned around after changing the oil and blowing it out a little to get the soot out of the turbo since it hasnt been really driven in almost a month. Did not dog on it but did let the boost build up a couple times and maybe got it up to 85 mph just steadily climbing, not like just stomping it and having it hit passing gear. Right when we started slowing down to get to our road is when I could hear a knocking noise and the slower we got the rougher it sounded. Was really missing pretty bad when I pulled it out back to park it. Thats when I got to looking into injector knock and stuff and was going to record it knocking and upload a video but upon turning the key it just sort of bounced and didnt really even try to crank. Sorta sounded like a misfire that misfired. Hopefully it is just an injector and can be fixed fairly cheaply (I know fixing these trucks aint really cheap but hopefully not engine damage).

 

Sounds like a hydro lock,don't try and start it something will break.After you get the injector(s) sorted check the fuel pressure if I had to guess by the sound of it you have low fuel pressure.That knock you heard was likely the injector hammering it's self to death.

 

Thanks. I'll see if I cant do some investigating. Hopefully thats all it is. Truck was running way too good until right there at the end.

 

A bad injector can/will sound like a rod knocking from overfueling. DON'T run the truck without repairing it as you risk the chance of burning a piston or worse.

 

Yupp, my motor hydrolocked on fuel.

Turned out to be 2 bad injectors.

Thanks to FTE its been running great.