Odd engine knock pattern..
#1
Odd engine knock pattern..
I had to put off getting my engine worked on until next week, so to pass the time I was wondering if anyone else has experienced my particular knock pattern...
In two other engines that I have experience with bad bearings, it was pretty obvious, a hard metallic knock like it was being beaten to death with a ball peen hammer at startup thru shutdown...
But my 4.2 is different, at cold startup it sounds just fine, no knock that I can hear, even if I hit the gas. But as soon as it reaches operating temperature, out comes the hammer! First noticable when changing gears, then a little while after that, you can hear it at idle. Every day its the same pattern, and I'm baffled about whats going on in there.
Anyone have any ideas/experience with this?
Maybe I just need some new muffler bearings or a tire stem lube job?
Thanks...Chester
In two other engines that I have experience with bad bearings, it was pretty obvious, a hard metallic knock like it was being beaten to death with a ball peen hammer at startup thru shutdown...
But my 4.2 is different, at cold startup it sounds just fine, no knock that I can hear, even if I hit the gas. But as soon as it reaches operating temperature, out comes the hammer! First noticable when changing gears, then a little while after that, you can hear it at idle. Every day its the same pattern, and I'm baffled about whats going on in there.
Anyone have any ideas/experience with this?
Maybe I just need some new muffler bearings or a tire stem lube job?
Thanks...Chester
Last edited by Chesterx; 03-09-2004 at 08:47 PM.
#2
#4
Chester,
If your engine is knocking at idle, we can probably rule out detonation or pre-ignition, so it sounds like a much more serious problem than simple air/fuel mixtures or gasoline grades. Could be a bent rod that only knocks when it heats up and expands. It's hard to diagnose without actually hearing it, but I'd take it to a mechanic and have him listen to it as soon as possible. Perhaps perform a compression test.
What year is your truck, and please don't say a 97 or 98. Cause if it is, this is probably your problem. www.leakingfords.com
Tom
And if that doesn't work, i'd probably try applying a small layer of peanut butter to the tailgate handle.
If your engine is knocking at idle, we can probably rule out detonation or pre-ignition, so it sounds like a much more serious problem than simple air/fuel mixtures or gasoline grades. Could be a bent rod that only knocks when it heats up and expands. It's hard to diagnose without actually hearing it, but I'd take it to a mechanic and have him listen to it as soon as possible. Perhaps perform a compression test.
What year is your truck, and please don't say a 97 or 98. Cause if it is, this is probably your problem. www.leakingfords.com
Tom
And if that doesn't work, i'd probably try applying a small layer of peanut butter to the tailgate handle.
#5
Yep, Busa, its a '97...already had a front cover gasket fail in 2001, but its starting to lose water again...
I think I'll pull the oil pan this weekend & give the bottom end and connecting rod bearings a close look, its driving me crazy not knowing whats knocking like that...
I'll keep ya'll posted on what I find...
I think I'll pull the oil pan this weekend & give the bottom end and connecting rod bearings a close look, its driving me crazy not knowing whats knocking like that...
I'll keep ya'll posted on what I find...
#6
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#8
My mechanic said he'd have a firm quote for me on Monday, so that thump ya'll will hear (other than my engine) is me hitting the floor!
I looked back at my paperwork from the 2001 fix, and didn't see anything about lower intake gasket repair & never heared anything about it, I guess they figured I'd find out about it on my own!!!!
It kinda hurts that Ford sold me a dog...
I looked back at my paperwork from the 2001 fix, and didn't see anything about lower intake gasket repair & never heared anything about it, I guess they figured I'd find out about it on my own!!!!
It kinda hurts that Ford sold me a dog...
#12
#13
Wow, that's expensive. You can purchase a high performance engine from Jegs and install it yourself for THAT price. Jeez!!
Is the knocking really really obvious, or can you trade it in on a new or used vehicle without them noticing it. If you can, just get rid of it. you can use that 4k as a down payment on a brand new truck.
If it were me, I wouldn't spend that much on something that just might break again.
If you have insurance on it, leave it parked in a really bad neighborhood with the doors unlocked and the keys on the seat
Tom
Is the knocking really really obvious, or can you trade it in on a new or used vehicle without them noticing it. If you can, just get rid of it. you can use that 4k as a down payment on a brand new truck.
If it were me, I wouldn't spend that much on something that just might break again.
If you have insurance on it, leave it parked in a really bad neighborhood with the doors unlocked and the keys on the seat
Tom
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