Spun rod bearing(s), need input

[ryanx99GS]

Okay, car has 74k. Recently took it to Ranken Tech to ask my friends teacher what my knock noise was, he said it was due to a spun bearing. We also rechecked compression there and did a leakdown test/vacuum/and boost. My compression is 160 on all 4, my leakdown is 3% for all 4. No vacuum/boost leaks at all, and very little shaft play. Dropped my oil pan today, found shavings. Each bearing has its typical wear, 2 in particular were bad. You could see where the source of the metal was coming from on #4, and #2 was starting to fail but we got to it in time. My question is, should I also change the main bearings too? My crank is perfectly fine, no grooves, mark etc. Before we put the new rod bearings in we are going to spray with brake cleaner and wipe with an emery cloth. But my question is, should I also change the main bearings? Thanks

*I am reusing the rods btw*

 

[absolute_DSM]

First of all, if you have a spun rod bearing, your crank and rod would have some damage that wouldnt be able to just throw in bearings and be ok.

But, if everything is ok, and you really dont have a spun bearing, then while youre going through all that work why not replace the mains? Gives some reassurance to your mind for the extra $50.00.

Mechanically, replacing the rod bearings isnt going to change anything that will affect the main bearings.

 

[bastard dsm]

best thing to do is tear the motor down and have the mach. shop
check clearences and micro polish the crank and throw new main and
rod bearings in it.The rods will have to be resized and make sure the cam
caps arnt scored and have the block decked and head milled.all n all new motor
is in effect.

 

[ryanx99GS]

So there is no possible way to reuse the rods? I currently don't have the money or time to pull the engine unless I can change the rods from underneath? My friend's classmates work at a mitsubishi dealer so I am getting a discount on the bearings etc. This is my DD. My mom currently uses my accord.

 

[bastard dsm]

you can reuse the rods if they are not beat up,have them resized and throw in a new
set of bearings.

 

[absolute_DSM]

If you literally spun a bearing, the rod(s) and crank are not going to be pretty.

Remember, cars dont care if you have time or money. They work as well as they are treated and built.

 

[ryanx99GS]

I totally agree and understand absoulte. Maybe this will give you a better idea. At idle, the car would not make a knock noise. When i revd up to 1.5k - 2k it would start doing it but not badly. I used to have a 88 Conquest and that thing knocked, and I mean knocked. When driving, you could not hear the knock unless I floored it and hit boost. I am not totally sure if I actually spun one or it was starting to fail. But, there are shavings at the bottom of my pan.

 

[Defiant]

Balance shaft bearing.

 

[jake247]

I spun my rear balance shaft bearing at 96k miles.


I pulled these out of my oil pan:

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here's a video. I was able to push the rear balance shaft up about a centimeter to an inch, and then let it fall down and go "clunk".

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The motor was still running and driveable when I finally stopped, but it was bad, noisy. you knew something was wrong.

There were a couple of scratches on my crank that my nail would catch on, so I opted against band-aid fixing the motor, and am dropping/ed a used built six bolt in, which should be finally finished up this weekend.

The engine was making an awful racket, i'll tell my comp to upload a vid of the noise tonight (i have slow internet). I think a lot of the noise was from the metal getting sucked into the lifters and messing with them.

 

[jake247]

also forgot: because it was the rear balance shaft, i was starting to lose oil pressure (I have an aftermarket gauge right off of the oil filter housing) but it still wasn't too low, but it was getting lower than normal.

here's a video of the noise that it was making.

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[tbonitz301]

wow. bet you cant wait to have that six bolt

 

[bastard dsm]

i hope you build you a 6bolt motor,cost's just ass much as a used jdm one.

 

[jake247]

yeah, i bought myself a used built six bolt, i was told ~5k miles, wiseco 8.5, crower rods, bc i/e 270's, ported 1g head (head was freshly rebuilt and unused.)

I think when everything is said and done, it will have cost me around $2600 or so to put it in the car. Overkill for what I want to do with the car.

depending on what you want to do with the car though, dropping in a used same 7 bolt will be much easier and cheaper.


Good luck.

 

[ryanx99GS]

Damn, that was the exact sound my car made.

I pulled my oil pan and found shavings. Rod and main bearings spun. Crank destroyed. As we were pulling the main seals we were drenched with the mixture of oil and water no thanks to the oil cooler. So, somehow water got through my oil cooler and completely fxcked my engine. It's ok though, I have a used 6bolt shortblock on the way While that is out I will be doing the balance shaft elimination also so to that also.