[dr0pt0pGT]

My car has recently started knocking on cold start and above 1800ish. It quiets down considerably after its nice and warm but its still there when I rev it and doesn't knock at all on start up after its warmed up. It doesn't stop if I remove the plugs/injectors. I'm going out right now to change the oil and filter and I'll stethoscope it tomorrow morning on cold start to try and identify if its top or bottom end. How can I tell if its a lifter or something more serious like a bearing? I'm also gonna run the old oil through a coffee filter and cut open the old oil filter and check for metal content.

Cold Start Video

Cold Start Video

Warm Rev Video

Warm Rev Video

[1989Gt.]

bearings spun.

[glittle75]

rod bearing. how you can tell, it only does it under load. like under revs and on initial start. bearing has spun, oil holes arent aligned, and when its under load, the knock is the sound of the rod knocking against the crank without lube. stop running it now, and depending on how bad your crank looks, you can probly just throw some bearings at it and stick it back in.

[96-GT_Josh]

Deff bearings. Had 2 cars blow up from that. Same sound. I would stop starting it until you rebuild. Tye second engine that blew up on me made that sound for maybe 10 seconds then threw a rob through the block. Heat and no lube are bad for internals.

[dr0pt0pGT]

That's what I was thinking but it just doesn't sound deep enough to be rod bearings. I won't be able to stethoscope it till tomorrow. And I thought the knock would get worse after it warms up if it was rod bearings? Mine quiets down. And it can barely be heard while i'm driving. Found out last night I had a bosch filter on it, so no check-valve, which could be part of the reason for startup knock. Installed a motorcraft and 5w/20. Haven't cold started it yet today to test but I will be on my way to work. I am prepared to drop in a lower mileage replacement if it goes catastrophic but I'm trying to pin point the problem first. Anyone ever have any luck replacing rod bearings with the engine in the car? Doesn't seem possible without removing the k-member or the engine but I figured I'd ask.

And can I just change the rod bearings or mains too? Doesn't seem like a good idea to just replace rods since they are all subject to the same conditions. If one goes, they all are probably on their way out. Thoughts?

[1989Gt.]

Originally Posted by dr0pt0pGT That's what I was thinking but it just doesn't sound deep enough to be rod bearings. I won't be able to stethoscope it till tomorrow. And I thought the knock would get worse after it warms up if it was rod bearings? Mine quiets down. And it can barely be heard while i'm driving. Found out last night I had a bosch filter on it, so no check-valve, which could be part of the reason for startup knock. Installed a motorcraft and 5w/20. Haven't cold started it yet today to test but I will be on my way to work. I am prepared to drop in a lower mileage replacement if it goes catastrophic but I'm trying to pin point the problem first. Anyone ever have any luck replacing rod bearings with the engine in the car? Doesn't seem possible without removing the k-member or the engine but I figured I'd ask. And can I just change the rod bearings or mains too? Doesn't seem like a good idea to just replace rods since they are all subject to the same conditions. If one goes, they all are probably on their way out. Thoughts?

Look imma be straight up with you this is one of those problems that your going to have to dig into the car we really cant solve anything, all we can tell you is it sounds like a spun bearing or rod knock Which were prob 90% sure ive had two spun bearings and it sounded just as this does.

It would be really dumb to try to replace bearings or rods with the motor still in the car your going to want to see other damage, otherwise you might fix the problem then something else could occur. Just pull the motor and replace it or rebuild it.

Like i stated before your going to have to do some digging.

[BAD98GT]

sounds like some bad bearings, if it goes away(completely away) after it warms up? stop driving it and check the oil pump located in the oil pan on baottom of engine, maybe clogged or going bad.....sounds like unsufficiant oil supply. the rods/ bearings may not b bad yet but if u continue to drive it they def will go out then it will knock all the time...also whens the last time u changed ur oil?also have u check the oil level.....dirty/oil oil could cause that knock also, cause the pump may be weak and is unable to pick up the old sludgy oil

[dr0pt0pGT]

It was due for a change when the knocking started. I changed it a few days ago and it actually got worse. Plus only half of what should have come out did... which means its burning oil like crazy cause its not leaking. I'm done with this 2v. Going to the Mark VIII 32v. Thanks for the help guys. Ill be sure to update this once I pull the motor and dig.

[OptionalStang]

mark MARK and AWAY !!!!!!!!!!!!!!!!!!!