Rod Knock?

[Sicarius428]

Hello guys, This isn't for me but for a friend of mine. I know its hard to diagnose a rod knock over the internet but I believe my friend's 2k GT has it. The only thing is that it comes and goes which is really odd to me. The car shudders and its doing the knocking thing then it pretends to be just fine then a couple minutes go by and it starts the knocking thing again. I know the 4.6's are very particular about low oil which he has run it low a couple times(light didn't turn on though I never trusted ford idiot lights). I am just curious if there are any other things that it could be that I can check. I just read something on spark plugs which I am gonna check this weekend. More in hope of than acceptance of a rod knock. Thank you for any thoughts or sugguestions.
Kevin

 

[the98stang]

Hello guys, This isn't for me but for a friend of mine. I know its hard to diagnose a rod knock over the internet but I believe my friend's 2k GT has it. The only thing is that it comes and goes which is really odd to me. The car shudders and its doing the knocking thing then it pretends to be just fine then a couple minutes go by and it starts the knocking thing again. I know the 4.6's are very particular about low oil which he has run it low a couple times(light didn't turn on though I never trusted ford idiot lights). I am just curious if there are any other things that it could be that I can check. I just read something on spark plugs which I am gonna check this weekend. More in hope of than acceptance of a rod knock. Thank you for any thoughts or sugguestions.
Kevin

First you need to do a compression test. If the numbers are consistant and around 150-200, your good. Then when the motor starts making the noise, unplug the COP wire. If the noise stops, then that cylinder is causing the knocking. You can also hook up an oil pressure gauge to check the oil pressure. You should also do a leak down test. Knocking would be a worse case senario. I've heard exhaust leaks that sound like knocking, so you never know. Hope this helps.

Tanner

 

[Sicarius428]

Thanks for the reply. I will give that a shot this weekend if I get a chance.
Kevin