I'm not a newbie to the early Mustang I6 as I've owned and restored a few over the years. My latest project a stock '65 coupe with I6 200 in it has an occasional loud rod knock that comes and goes. I don't have any history on the engine, so poured some seafoam in and let the engine idlel parked for about an hour while the knock slowly went away. Shut things off so they could cool enough and changed the oil giving it fresh 10-40 and a filter.
The knock had gone away completely but after the oil change when I started the car it came back. I pulled the valve cover to have a look and tried adjusting the lifters one at a time with the engine running to see if I could isolate the problem, no love though. The knocking was still coming and going, not based on rpm so much as it would just slowly get louder and slowly go away even at idol. This isn't my first rodeo with the I6 rod/lifter noises so I removed the rocker arm assembly, (stock) and poured some marvel down the rods onto the lifters themselves expecting one was sticky. I also found some "globs" of oil stuck to the head when I pulled the valve cover, so God only knows when she had her last oil change.
I let the marvel sit for a few hours and I pulled each rod one at a time to inspect the lifter. When I came the the lifter for the exhaust valve on cyl #4 I pulled the rod, looked down the channel, and didn't see the lifter only the lobe on the cam, (which looked flawless incidentally). I decided at that point to pull each of the plugs and found on cyl #4 I had some unburnt crud built up on the plug. I guess I found my culprit!
My question and problem now though... Has anyone else had a lifter fall into the engine past a lobe on the cam when they've pulled a rod out? This is a first for me, I've swapped heads, even full rebuilds on these engines before and never experienced this problem. I'm not sure where to take it from here. Obviously the head has to come off one way or the other to put the lifter back in its channel, (if its salvageable), but I don't recall from previous build that there was ever enough room for a "Good" lifter to drop down past the cam, no matter the position of the cam.
I'm a little embarrassed asking for the help for such a stupid thing, but I sincerely appreciate any personal experience!
The knock had gone away completely but after the oil change when I started the car it came back. I pulled the valve cover to have a look and tried adjusting the lifters one at a time with the engine running to see if I could isolate the problem, no love though. The knocking was still coming and going, not based on rpm so much as it would just slowly get louder and slowly go away even at idol. This isn't my first rodeo with the I6 rod/lifter noises so I removed the rocker arm assembly, (stock) and poured some marvel down the rods onto the lifters themselves expecting one was sticky. I also found some "globs" of oil stuck to the head when I pulled the valve cover, so God only knows when she had her last oil change.
I let the marvel sit for a few hours and I pulled each rod one at a time to inspect the lifter. When I came the the lifter for the exhaust valve on cyl #4 I pulled the rod, looked down the channel, and didn't see the lifter only the lobe on the cam, (which looked flawless incidentally). I decided at that point to pull each of the plugs and found on cyl #4 I had some unburnt crud built up on the plug. I guess I found my culprit!
My question and problem now though... Has anyone else had a lifter fall into the engine past a lobe on the cam when they've pulled a rod out? This is a first for me, I've swapped heads, even full rebuilds on these engines before and never experienced this problem. I'm not sure where to take it from here. Obviously the head has to come off one way or the other to put the lifter back in its channel, (if its salvageable), but I don't recall from previous build that there was ever enough room for a "Good" lifter to drop down past the cam, no matter the position of the cam.
I'm a little embarrassed asking for the help for such a stupid thing, but I sincerely appreciate any personal experience!