This knocking has my stumped... not rod knock...

[Munki]

Well, the past month my motor has been making this wierd knocking from about 2.5k to 4.5k rpms. The motor runs really strong and hasnt gave me any problems at all... I've been doing alot of spirited driving and the knocking hasn't gotten any worse... At first I though for some reason it might be the injectors so I replaced them all with new ones and that did nothing. I did notice though, when I start the car and take out the coil pack on the 1st cylinder the knocking completly goes away. The same happens If I put it back in and disconnect the injector plug for that cylinder. So the knocking has something to do with cylinder one.

So far I've:

-Dropped oil pan to check for pieces of bearings, but found nothing at all, not one little shard...

-Took off valve cover just to inspect everything

-Timing chain was ok

-Checked my spark plug for #1, even replaced it with a new one

-Check for loose bolts on mani

-check for cracks in mani

Im kinda lost now... Wish my mechanic wasnt on vacation right now... Anyone else ever have this problem? Its a redtop BTW...

Im pretty sure its not rod knock, i've been driving this car hard lately and it still hasnt gotten any worse. Never overheated or anything..

[project-D180]

did u happen to check the bearing itself to make sure of any bad wear marks??

[TrustS13]

Shit has a spun bearing more than likely, by driving on it you are making it worse.

[Munki]

Shit has a spun bearing more than likely, by driving on it you are making it worse.

well, it hasnt gotten any worse at all... Like I said, ive been doing lots of hard driving and making long trips with it knocking. There no way it would still be running if that was the problem.

[sirfallsalot243]

Compression test it?

[Killa_D]

Shit has a spun bearing more than likely, by driving on it you are making it worse.
did you even read what he wrote? When he takes the coil out or disconnects the injector knocking goes away. So is not a spun bearing :doh:.

[TrustS13]

^ Thats how you check for a spun bearing genious

[Munki]

^ Thats how you check for a spun bearing genious

Well, besides a spun bearing what else whould cause a knock in the first cylinder? Ill just let my mechanic check the bearings when he gets back, but before that i kinda want to rule out any other problems that could be causing all this...

[str8drift27]

stuck valve?

[tercel drifter]

I say you spun a bearing. This happened to me 2 years ago as well, same situation. At higher revs you may not hear it because there will be more oil pressure. Mine was knocking around the + or - 3k range.

I say don't drive your car and if its possible you might get away with being able to jack up the car and replace the bearing with out lifting the engine out the car.

[TrustS13]

Seriously man, unfortunately it sounds like you have a spun bearing. I drove my DSM for like 1 month with a spun bearing, for 2 weeks it didn't get worse or louder, but trust me, you are doing more damage. I recommend not driving the car if at all possible!

[Munki]

uhmm, does anyone know the part number for the bearings? ill just order it now and hope thats the problem.

Edit: nevermind about he part number


Anyone have any tips and advice for replacing rod bearings?? Never done this...

[tercel drifter]

May as well order new rod end bolts as well. Good insurance I wouldn't reuse them.

[sirfallsalot243]

You can do it by jacking the car up and dropping the oil pan, provided the spun bearing didnt do any damage to the crank or rod. If it didnt, it should just be a matter of getting in there and taking the rod bolts out and replacing the bearing.

Not really an easy task, but beats the hell out of a full rebuild out of the car.

[Walperstyle]

any metal fragments in your oil? Oil filter?

[SinGarage]

I vote for bearing also. When you disconnect anything on any cylinder to keep it from firing and the knock goes aways...that would typically be a bearing. Make sure to check the journal on the crankshaft on cylinder one to make sure it's not out of round...specially if you can see the copper on the bearing itself. GL.

[smink]

If its a spun bearing your going to want to have the crank checked by a machine shop to make sure it can be reused. Which means pulling the engine and dissasembling it. At minimum the crank needs to be polished. And if it damaged the crank enough the crank will need to be machined down and you will have to use a different size bearing to compensate for the amount machined off. Not to mention the rod bolts will need to be replaced IF the rod is salvagable. Not to be a dick but, the internet is an amazing thing search it for how to check for a spun rod bearing, also how to fix it based on how bad the damage is.