I Thought My Disco Engine was Miraculously Healed - Wrong!
#11
I would say that the lifter is weak and after a long drive it gets primed, then loses its prime after several short trips.
#14
Mike, yes I'm planning to tear down the engine (at least to the point of replacing lifters). That's why I'm asking questions. I seem to have a fairly unique problem and I'm trying to research it to the extent possible before digging into the engine.
#16
#18
hey i just wanted to jump in here. Disco Mike would be correct (again...). if you are going to do the lifters then you should replace the cam shaft as well. take a look at the info on this site. http://www.v8engines.com/engine-4.htm
#19
This might be a stupid suggestion, but have you checked the exhaust? Is your pipe hitting the frame somewhere and causing the knock? I only say this because at idle and a little above, my exhaust hits the frame and knocks. Goes away when I get above idle. Had to get the old coat hanger out.
Just thought I would throw that out there.
Just thought I would throw that out there.
#20
I found this doing a search ... my engine is making what sounds like the exact same noise. As Bryan described, this noise is coming from the top driver's side of the engine and starts when the engine is warm and is present when the engine is idling or just above idle. I would also add that it is too regular to be anything other than something inside the engine (ie it's not the tailpipe hitting the frame).
Also, I timed it and it seems to be happening at about 1/2 of engine RPM. For example at 800 rpm this tick - or knock or whatever it is - is happening at 400 times per minute. I don't know if this frequency helps narrow it down or not. If it were one single lifter I think it would happen at 1/4 of engine speed (I think) ... ??
Another thing to note is that this noise has been going on for over 1 year / 6k miles and has not changed in character. The truck runs just fine had has no loss of power. I have had two different independent mechanics look at it and both think it is a lifter, and not something to tear into the engine to fix if that's all you're going in there for. I am still cautious, though, and am going to another mechanic next week - this one and the last one are very knowledgable LR guys - and will see what he says.
This is just FYI unless someone has additional thoughts. Will let y'all know if I find anything else.
Also, I timed it and it seems to be happening at about 1/2 of engine RPM. For example at 800 rpm this tick - or knock or whatever it is - is happening at 400 times per minute. I don't know if this frequency helps narrow it down or not. If it were one single lifter I think it would happen at 1/4 of engine speed (I think) ... ??
Another thing to note is that this noise has been going on for over 1 year / 6k miles and has not changed in character. The truck runs just fine had has no loss of power. I have had two different independent mechanics look at it and both think it is a lifter, and not something to tear into the engine to fix if that's all you're going in there for. I am still cautious, though, and am going to another mechanic next week - this one and the last one are very knowledgable LR guys - and will see what he says.
This is just FYI unless someone has additional thoughts. Will let y'all know if I find anything else.