knocking noise not making any sense?????

[angie1015]

cruising along and all of a sudden i hear a knocking in my motor so i stopped. then it went away. 10 min later starts knocking again so i stopped again this time it kept up so i anchored and took the valve covers off. I thought it was a push rod. it wasnt. started it up agian and while at idol no noise. start bringing up the rpms and theres the knocking again. thought it was a rod however i ended up driving over 3 hours to get home at 5 mph. IF it was a rod would it not have went already. i can let the boat cool for an hour and when i start it it will idol fine but as soon as i race it the knock comes back. rod going bad??? now the kicker, smoke pouring out of the breather(blow by)... now if it were a rod that wouldnt cause massive smoke out of the breather. no smoke coming out of the exhaust. (no more then usual) so what can it be. I just had the intake manifold off and chaged the gasket. could i have dropped something in the motor causing this. the boat runs great just a banging from the motor under load or if you race it for a minute. the hotter the engine gets the worse it is. cant put my finger on it. sounds like it has to be more then one thing. however the boat was running great up intil then. getting great oil pressure. not running hot. somebody help. when i took the valve covers off and turned the motor over smoke puffed out of the motor where the push rods go in. ford 460 1987 7.5

 

[Reel Poor]

Re: knocking noise not making any sense?????

Do a compression test. It may have detonated a piston. Look at the plugs when you remove them.

 

[lilmandavis]

Re: knocking noise not making any sense?????

man those covers arent the easiest to remove, at least on mine they arent. 460's are very temperamental. but it sounds like part of the rotating is damaged pretty bad. im with the bad piston. you didnt drop any bolts down the intake port did you? may have punched a hole in your piston. does it seem to missfire? were all the holes filled by bolts when you were done? 8)

 

[Boatist]

Re: knocking noise not making any sense?????

I do not know the motor but sounds like a lot of blow by.
Could be a stuck piston rings, a lot of carbon build up bad rist pins.

Are you running 10 - 40 oil that is know to cause stuck rings??

Why did you have the intake manifold off??

When you had the valve covers off were both sides getting oil??

High oil presure can mean have a blockage somewhere so oil does not get to the heads or something like that.

 

[angie1015]

Re: knocking noise not making any sense?????

i was thinking maybe i dropped a bolt when i had the manifold off and maybe it damaged a piston. why else would it knock and smoke together. the smoke coming out of the blow by is on one side only which narrows it down to one side of the motor. i pulled one plug already and it looked fine. ill try to pull them all today. the oil pressure does seem a litte high but im not sure i would trust the gauge enough to believe that. actually it doesent missfire at all. i pulled every plug while running and the noise never went away.???

 

[lilmandavis]

Re: knocking noise not making any sense?????

do a compression test. those litttle fiber optic cameras are the greatest invention ever. if you could get your hands on one get it. i wouldnt drive it much more till i figured out what the prob is. these fords get money hungry quick.

 

[angie1015]

Re: knocking noise not making any sense?????

ok i went down there today. didnt do a compression test however i pulled each plug out one at a time and started the moter. definitly compression in all cylandars. while cold it will run quietly. once it warms up and you bring the rpms up it sounds like rod however it doesent make the knocking noise on till i let go of the throttle then it knocks on the way down rpms. also smoking like crazy out of the blow by. rods dont smoke but my engine does. i let it run for about 20 min and as long as idol no noise just smoke. however put a load on it and the knocking gets much worse but does come and go like something banging around in the oil pan.

 

[lilmandavis]

Re: knocking noise not making any sense?????

use a long screwdriver to your ear and to the engine and isolate where the noise is comming from. move around while listening through the screw driver. if its comming from the cylinder wall area theres a bolt in there. there aint nothing bouncing round in the oil pan except for oil. also listen behind the bell housing at the coupler. mine sounded like a tin can of rocks being shook under water. and it was only under power. need to get a compression check. rent at auto parts store for free with a deposit. the blowby is not good at all. that leads me to a piston leaned out or a bolt in there. could of been timing whats the timing? is the engine spark pinging as well? what is the timing set at? did the engine miss at all when you were pulling the wires off one at a time worse than its running now?

 

[Boatist]

Re: knocking noise not making any sense?????

Smoke on only one side does not make sence to me. If it is blow by into the pan then it would smoke the same on both sides. since there is no seperator between sides. Could it be a cracked head? Does one side have a PCV valve to suck up the smoke on one side?

 

[whywhyzed]

Re: knocking noise not making any sense?????

"rods dont smoke but my engine does"
??
No offence, but this is a tutorial on how NOT to troubleshoot..
Spend the $8 on a compression tester...get some numbers before you convince yourself it's one thing or another....

if there's smoke coming out the breather, the engine probabky has to come out.....but it's easier to check compression before pulling it.

 

[angie1015]

Re: knocking noise not making any sense?????

there is smoke coming out of both vavle covers i just couldnt tell because there is no breather on one of them. I think its possible that when i had the manifold off maybe i dropped something in the motor that is stuck. prob damaged the piston causing the smoke and the noise. i will pull the plugs and try to get a magnet in the hole and fish something out. keeping my fingers crossed. At least if thats the problem i can drive it for another month and pull the engine over the winter. A little oil burning but wont do any more damage.
ps senior chief let me know where you get those 8 dollar compression testers. sounds like a steal. I actually just bought one but it cost me 30 bucks.

 

[Reel Poor]

Re: knocking noise not making any sense?????

To continue running the engine will only cause more catastophic damage.

 

[HT32BSX115]

Re: knocking noise not making any sense?????

Sorry,


You might be done here.

You probably should pull the engine. In the best case you might have a lifter that won't pump up or possibly a bent push rod. In the worst case as someone said earlier, broken/cracked piston, broken ring(s), spun rod bearing. (if it's a spun bearing, rod or main, things won't last long before something REALLY BAD happens.

Running it at all until you know might not be a good idea.


Regards,

Rick

 

[Daddy O]

Re: knocking noise not making any sense?????

A rod knock would be heard as soon as the engine starts.
If you dropped a bolt in the intake. The first thing that would be affected is the valve. Most bolts probably wouldn't fit between the vavle and the seat. Anyway the damage is all ready done. Remove the plugs and look for a differance of color. i.e. oil, fuel, water, or a damaged plug. Than perform a compression check. If a bolt did get into the motor, the valve is more than likely damaged, and will fail. Destroying your engine. altogether.

 

[Aquaman]

Re: knocking noise not making any sense?????

Sounds like a valve seat. Do a compression test to isolate the cylinder. As others have said don't run the engine unless you'd rather buy a new one as opposed to fixing the one you have.

 

[Boatist]

Re: knocking noise not making any sense?????

I also agree do a compression check. That quick and easy. Trying to fish thru a spark plug hole with out knowing which cylinder is bad makes no sense to me.

Do the compression test then pull the head on the bad side and see what wrong. Anything in the engine will destroy the entire engine in a very short time to the point that it can not be rebuilt.

 

[Daddy O]

Re: knocking noise not making any sense?????

At this point, if you haven't ran the engine is quite possibily head damage. Run any further the block will be effected.

 

[bamadave]

Re: knocking noise not making any sense?????

You say you bought a compression checker, so what's the compression in each cylinder?
To continue running anything mechanical with a known problem is nothing but stupid.

 

[rowndman]

Re: knocking noise not making any sense?????

cruising along and all of a sudden i hear a knocking in my motor so i stopped. then it went away. 10 min later starts knocking again so i stopped again this time it kept up so i anchored and took the valve covers off. I thought it was a push rod. it wasnt. started it up agian and while at idol no noise. start bringing up the rpms and theres the knocking again. thought it was a rod however i ended up driving over 3 hours to get home at 5 mph. IF it was a rod would it not have went already. i can let the boat cool for an hour and when i start it it will idol fine but as soon as i race it the knock comes back. rod going bad??? now the kicker, smoke pouring out of the breather(blow by)... now if it were a rod that wouldnt cause massive smoke out of the breather. no smoke coming out of the exhaust. (no more then usual) so what can it be. I just had the intake manifold off and chaged the gasket. could i have dropped something in the motor causing this. the boat runs great just a banging from the motor under load or if you race it for a minute. the hotter the engine gets the worse it is. cant put my finger on it. sounds like it has to be more then one thing. however the boat was running great up intil then. getting great oil pressure. not running hot. somebody help. when i took the valve covers off and turned the motor over smoke puffed out of the motor where the push rods go in. ford 460 1987 7.5

 

[rowndman]

Re: knocking noise not making any sense?????

Doesn't sound good. Run a compression check on all 8 cylinders. Sounds like a bad piston / rings; the compression check will confirm this, and show you which one it is.