Help with inspecting crank & rod bearings! Also spun bearing noise diagnosis help??!! [Archive] - DSM Forums: Mitsubishi Eclipse, Plymouth Laser, and Eagle Talon Forum:

: Help with inspecting crank & rod bearings! Also spun bearing noise diagnosis help??!!

06-10-2003, 07:31 PM
Car is a 1991 TSI AWD stock engine with about 135k miles on it..

Have been trying to diagnose a spun bearing type noise after doing balance shaft removal, timing belt job and water pump.... all new timing pulleys, tensioner, belt, harmonic balancer...

car makes grinding spun bearing type noise when running, noise increases with rpm. on low RPMs noise will quiet or go away when clutch is pushed in... still has normal oil pressure..

Double checked all the pulleys and bolts for the timing belts and everything is okay.. Pulled the oil pan, no noticable metal shavings, rod bearings have some play from crank to flywheel, none side to side... couldn't find feeler gauge, so pulled the crank bearings out and inspected them n journals, some wear but nothing that looked really worn.. also pulled rod bearings and they looked okay..

here are pics of the bearings n journals:

So i try turning the crank and look for anything loose or noisy... there is some noise or loose sound near piston #4.. disconnected rods of both #3 and #4, sound and looseness still there.. apparently it's from the clutch/flywheel.

Would a loose bolt on the clutch or bad clutch or bad throwout bearing cause noise similiar to spun bearing? i'll have to pull the tranny out to know for sure..

anyways.. while i have the bottom end apart... just how bad the crank and rod bearings? there is some wear but no heavy scratches... is the crank still good?

Also any ideas on what might cause loud spun bearing type noise? the rear balance shaft has been replaced with the stub, front one is there but just sits there.. bolt on the oil pump gear is tight, crank pulley bolt is tight.

any help would be appreciated, running outta ideas and don't wanna put everything back together n still have the same problem

06-15-2003, 11:40 AM
Mine does the same thing,,when i push in the clutch it goes away.My guess its the throw out bearing.The weird thing is ,it did it before i put in a new clutch and throw out bearing,,and it still does it after the new one,,,very wierd:rolleyes:

VTEC Killer
06-15-2003, 03:32 PM
mine too its my throw out bearing no noise when cold, a lil noise when warm and nothing when hot weird as hell if I bang through the gears HARD the noise goes away I dont know......but its really old and im in need of a new clutch .02

06-15-2003, 06:40 PM
thats kinda funny, when i blew mine up my bottom end looked just like that, except for the fac that i had a cracked bearing, i will try and get you pics asap. But my question is what kind of noise is it making??? mine sounded pretty damn bad like something slapping around in the bottom end, so good luck and ill try to get ya my pics too.

06-15-2003, 10:23 PM
There's a little more embedded material than I like to see but otherwise the rod bearings don't look too bad.

You might want to get other opinions, sometimes pictures can fool the eye. But the crank bearings look like they have given about all they have to give.

VTEC Killer
06-16-2003, 04:40 PM
the journals on your crank dont look so hot are the bearings smooth or does your finger nail catch anywhere? any discolorations? i.e. bronze, copper,ect....(hard to tell from the pics) what kind of oil were u using?

06-16-2003, 06:12 PM
The wear on the bearings looks worse in the pics because of the flash....

there was still oil pressure, so the crank bearings were still working okay.. i still need to check the clearances with a feeler gauge...

the noise is very loud and a grinding type noise... coming from the tranny/clutch/flywheel area.. possibly could be the throwout bearing, though it's loud as hell.. will have to pull the tranny to see what is really wrong with it...

as for oil, i put in mobil synthetic mix.. but i've only recently owned the car... so no idea on oil history.. the car has about 135k mileage, so shouldn't some wear on the bearings should be normal?

no major discolorations other than the back of the rod bearings were a bit brownish black...

06-16-2003, 09:38 PM
You're not going to be able to measure clearance with a feeler gauge. That will only tear up the bearing if you try it.

I'd expect the bearings, even from a high mileage engine, to be dark grey in color and not much else. The amount of embedded material in the rod bearings and the amount of scratching on the mains indicates a bearing failure and junk in the oiling system at some time in the past..

Anyway, if taking the engine apart again you might want to have a professional look at one of the main bearings. Also, what sort of oil pressure are you seeing.

06-16-2003, 11:20 PM
So are the bearings and journals worn that bad that the lower end needs a rebuild soon???

The oil pressure gauge was a quarter at idle..

i did a compression test before and numbers were all around 140psi...

how much more work will it be to pull the crank? timing cover/belts r off, oil pan is off and will be pulling the awd tranny shortly....

of course i'm also considering the option of just parting out the car.. it's a 91 tsi awd, and it might be worth more in parts than fixing it up and then selling it..

i just picked up a nice 1g with mods that's my main dsm..


VTEC Killer
06-17-2003, 04:12 PM
you "CAN" check your tolrances(sp) with plasti-gauge most parts stores should have it just follow the directions its simple and since youve gone this far you should check it. as far as the noise it prob the throw out bearing btw did you mark or label the main caps? because they have to go back on in the proper place bearings far as a worry if u got one dsm that your better car id say screw it unless u wanna get this one running again for more money my .02

07-19-2003, 02:55 PM
But from what i was looking at why couldn't he just reassemble the bottom end with new rod and crank bearings ? and see if that cured the problem.. I have a rod knock on a 7 bolt and i was going to change the rod bearings till i had the other engine rebuilt and assembled, so i could still drive the car. Am I NuTs ?

07-19-2003, 03:11 PM
Its gonna be a patch job but if all you are looking for is transportation and don't beat the engine this would (replacing the bearings) get you some more miles.

To do it right you need to have a machine shop measure the crank (and probably replace it). Then, they would fit new bearings all to the proper tolerances. These would go back into a block that has been boiled out and is free of junk in the galleries.

07-19-2003, 04:00 PM
How long do u think it would last if was just bone stock and driven around if i was ez on it ?

Also would u just use STD size or go with over size ?

I figured it would work temporarly but not permanent.

VTEC Killer
07-19-2003, 05:28 PM
it would prob. be fine as a patch job the problem is u could have uneven wear on the main journals therefore more impact on the thrust bearings.......if its just a daily id replace the bearings(use plastic gage to check the clearence)if its close to spec.and use a quality motor .02

07-20-2003, 03:55 AM
Thanks for the reply, i sorta,kinda,maybe figured it woulda worked and for $150 or so, to get a $1300 2g (don't ask :P) back on the road untill i have the other engine built would be great. Once I have title in hand and oil pan off I'll update ya with the success/failure of the bearing replacement and or endplay...