Hey guys, I've been lurking through these threads for years and gotten so much good info. Many thanks for that!
My issues have gotten too specific so I'm asking on my own now; I've had this f350 for a couple years now and it's been parked for the better part of 9 months while I've messed with the fuel injectors trying to eliminate this intermittent "thumping" (I've been known to call it the "womp womp"). The details of the womp really haven't changed much despite a lot of work and varying tests. I first noticed it when slowing down from freeway speeds to exit, at first (from inside the truck) it sounded exactly like an exhaust manifold ticking, but as I slowed and the engine returned to idle RPMs it became a very deep and pronounced thumping in time with engine revolutions. After some research I decided to change my injectors, since I'd owned the truck a year and hadn't done that. When I pulled them there were a couple SERIOUSLY fouled up injectors, covered in much and carbon clear up to the big threads, one that came out in half and took a couple days to pull out the bottom cup (a story and a homemade tool worth another thread by itself). So I bought remans from a reputable diesel shop, cleaned the actual devil out of each of the ports, replaced all the return lines and one high pressure line that had a cracked nut, it ran great for a week or 2, but the thumping came back like before, always after running under load for a bit, never from idling or at start up. I blamed leaky injector seats and spent a lot of time over the next months driving it very little, mostly to test it; and always pulling, cleaning, and re-seating the injectors. I finally accused the remans of having different 'pop' points, plus causing a lot of wear and tear to them conatantly pulling them and cleaning them. So I broke down and replaced all injectors with brand new ones. The truck runs so smooth and great now, until I run it at high RPMs for a few minutes, then the thumping comes back.
I have all kinds of deep fears about valves/guides, compression issues, etc. But I'm always stuck on the very specific relation to the higher heat and RPMs, if i rev it up after a cold start it doesnt do it, only after a susptained load for a few minutes. Then once the truck cools a little it sounds like an absolute dream again.. but the video I took today (see link below) is right after getting off the freeway, any ideas of what to look at first?
As a probably separate issue, I've been chasing down one of the few issues that will cause the obd 1 to throw a light, I believe I have a bad coolant temp sensor, i have ordered a new one but it did this once before, I pulled it and cleaned it and it went away for months, it's back so im just replacing it now, I doubt that could be related to any of the above issues but I'm no pro.
My issues have gotten too specific so I'm asking on my own now; I've had this f350 for a couple years now and it's been parked for the better part of 9 months while I've messed with the fuel injectors trying to eliminate this intermittent "thumping" (I've been known to call it the "womp womp"). The details of the womp really haven't changed much despite a lot of work and varying tests. I first noticed it when slowing down from freeway speeds to exit, at first (from inside the truck) it sounded exactly like an exhaust manifold ticking, but as I slowed and the engine returned to idle RPMs it became a very deep and pronounced thumping in time with engine revolutions. After some research I decided to change my injectors, since I'd owned the truck a year and hadn't done that. When I pulled them there were a couple SERIOUSLY fouled up injectors, covered in much and carbon clear up to the big threads, one that came out in half and took a couple days to pull out the bottom cup (a story and a homemade tool worth another thread by itself). So I bought remans from a reputable diesel shop, cleaned the actual devil out of each of the ports, replaced all the return lines and one high pressure line that had a cracked nut, it ran great for a week or 2, but the thumping came back like before, always after running under load for a bit, never from idling or at start up. I blamed leaky injector seats and spent a lot of time over the next months driving it very little, mostly to test it; and always pulling, cleaning, and re-seating the injectors. I finally accused the remans of having different 'pop' points, plus causing a lot of wear and tear to them conatantly pulling them and cleaning them. So I broke down and replaced all injectors with brand new ones. The truck runs so smooth and great now, until I run it at high RPMs for a few minutes, then the thumping comes back.
I have all kinds of deep fears about valves/guides, compression issues, etc. But I'm always stuck on the very specific relation to the higher heat and RPMs, if i rev it up after a cold start it doesnt do it, only after a susptained load for a few minutes. Then once the truck cools a little it sounds like an absolute dream again.. but the video I took today (see link below) is right after getting off the freeway, any ideas of what to look at first?
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As a probably separate issue, I've been chasing down one of the few issues that will cause the obd 1 to throw a light, I believe I have a bad coolant temp sensor, i have ordered a new one but it did this once before, I pulled it and cleaned it and it went away for months, it's back so im just replacing it now, I doubt that could be related to any of the above issues but I'm no pro.