Possible spun bearing

[Assy]

I think i spun a bearing my oil light will come on when car is warm and at a stop. I noticed when not under load when i rev it makes a knocking sound it doesnt sound like lifter tick, I listened to the oil pan and heard the knock clearly. I also never seen any shavings in the oil or pan. If i caught it fast enough can i just replace the bearings?


Update: I pulled the engine out and looked at the oil pump. When i spin it by hand it will be hard to turn in one spot. does that mean its bad? Also dropped the pan would i visually be able to see if i did spin the bearing?

Thanks

[Austin@STM]

Sounds like you spun a bearing. You wont be able to tell until you take it apart for sure. If they did spin you will need to get everything remachined. You will also have to clean everything that oil goes through and replace the oil pump and cooler at a minimum.

-Austin@STM

[Assy]

What should I look for when I take the rods apart? Also will the block have to get machined to

[Austin@STM]

Depends what bearing spun. It its a main bearing then yes, also if enough debris got through the engine and scratched it all up it will need machining.

You will know what your looking for when you find it. One or more of the bearings will look different than the other, and probably wont be smooth or clean looking.

[Assy]

So I should take the rod ends off to look at the bearings? Also witch one is main the ones on crank?

[Amphiron]

. main bearings = bearings that ride on the block. connecting rod bearings ride on the connecting rod journals

[Assy]

yea main bearings were bad the rod bearings were ok but im going to change them since they are out. Also whats a good way to clean the oil passages

[CoreyB]

Did they spin or just wear out? It makes a huge difference.

[Assy]

Well im not sure. The oil light came on for a few days(only for a sec each time) then i heard a knocking so i turned it off and inspected and found my bearings were bad. Whats the difference?

[CoreyB]

Its easy tot ell. If the bearing spun then it means the entire bearing turned in its holder. The back of the bearing would be worn along with the inside. If the wore out and didnt spin you may be able to just replace them but check your oil clearences. If they spun, its full rebuild time.

[Assy]

Its easy tot ell. If the bearing spun then it means the entire bearing turned in its holder. The back of the bearing would be worn along with the inside. If the wore out and didnt spin you may be able to just replace them but check your oil clearences. If they spun, its full rebuild time.

Now i see why its called a spun bearing, Then no they didnt spin wore out. my crank has to be machined to tho doesnt it? it has some scratches on the main bearings

[Austin@STM]

Now i see why its called a spun bearing, Then no they didnt spin wore out. my crank has to be machined to tho doesnt it? it has some scratches on the main bearings

Post up some pics.

[Assy]

here you go
12011200120212031204
http://i55.tinypic.com/6syxe8.jpg
http://i53.tinypic.com/2co1t7k.jpg

[Assy]

Also would bad bearings cause low oil pressure?

[CoreyB]

Yes it needs to be machined and yes the worn bearings will cause the low oil pressure. The oil clearances for the mains is only like .0015". As that gap gets bigger its easier for the oil to escape, making it much harder to maintain pressure in the oil system.

[Assy]

ok i c, another member on the other site said i have to get the bearing clearances checked wat does that mean?

[CoreyB]

There are really two ways of doing this. One is to put the bearings in without the crank and measure the inside diameter, and measure the outside diameter of the crank journal that rides in that spot. You then subtract the crank journal diameter from the bearing measurement. The difference is the oil clearance.
Another easier way is to use plastigauge. You can buy it at any parts store if you ask for it. This is a thin piece of plastic that you put between the bearing and the crank, torque to spec then take back apart. The plastic is squeezed and widened. You hold the plastigauge up against the package it came it which is laid out to tell you the clearance.

[Assy]

is that after i get the crank machined? Also whats the point of doing this?

[CoreyB]

The point is to know if the clearances are ok or not, its essential in engine building. If you have the crank machined they should supply you with bearings that are thicker to meet the clearance spec. You still need to check though so you know the machining was done correctly. Its a lot of work and money to through something together not knowing if its right or not.

[Assy]

And if they dont give me the bearings could i ask them what size i need like .25 etc? and ok so do i check all of them or just one?

[CoreyB]

Before having it machined you should ask if they will be providing bearings. I actually recommend buying a reground and using yours as a core. It will come with new bearings. Just make sure you really clean the oil galleys out VERY well. Use carb cleaner, compressed air, and a gun cleaning kit. And check all the clearances, the mains are quik because you can check them all together by putting plastigauge on each main then torqueing the main girdle. The rods you do one by one. Its not bad though because at that point you should be installing new rings so it slows you down. Going slow is a good thing because you can keep a clear head and think about everything you are doing carfully.

[Assy]

Before having it machined you should ask if they will be providing bearings. I actually recommend buying a reground and using yours as a core. It will come with new bearings. Just make sure you really clean the oil galleys out VERY well. Use carb cleaner, compressed air, and a gun cleaning kit. And check all the clearances, the mains are quik because you can check them all together by putting plastigauge on each main then torqueing the main girdle. The rods you do one by one. Its not bad though because at that point you should be installing new rings so it slows you down. Going slow is a good thing because you can keep a clear head and think about everything you are doing carfully.

Reground crank? Where would I get one and how much would it be? Why should I have to use it as a core. Ah I hate going slow haha but I will. How many cans of carb cleaner should I get? And couldn't I just get my crank Reground? I need to save money

[CoreyB]

Being NA, it may be cheaper faster and easier tho buy a engine and replace it. I see them for like $500 quite frequently.

[Assy]

Yea but i got quoted at 65-75 for my crank to get machined and 72 for a oem bearing kit thats cheaper then 500. but Why should i get a new engine?

[Assy]

If you lived in my part of the world, you'd take the crank to the machine shop and get it reground 10/10 which means that both the mains and big ends are reground 10 thou undersize. You then get a set of 10 thou main and bigend bearings and slap it together.oh and thrust washers.

It's a bit pointless doing just the bottom end, ideally you should pull the heads, pull the pistons, get the block honed & cleaned, fit new rings. You'll only need new stemseals if it's high Ks or been cooked, if you're lucky you can reuse the headgaskets, so long as there's been no previous coolant loss or overheating.
Pros don't use plastigage, not here anyway, they use a bore gauge.
Steve

Thats what i was gonna do. Heads have been rebuilt and just put on thanks

[CoreyB]

If you lived in my part of the world, you'd take the crank to the machine shop and get it reground 10/10 which means that both the mains and big ends are reground 10 thou undersize. You then get a set of 10 thou main and bigend bearings and slap it together.oh and thrust washers.

It's a bit pointless doing just the bottom end, ideally you should pull the heads, pull the pistons, get the block honed & cleaned, fit new rings. You'll only need new stemseals if it's high Ks or been cooked, if you're lucky you can reuse the headgaskets, so long as there's been no previous coolant loss or overheating.
Pros don't use plastigage, not here anyway, they use a bore gauge.
Steve

Nothing you just said makes sense. You may WANT to get the machine work done 10/10 but that only works if .010" is enough two clean up any damage to the crank. 10/10 generaly works for a crank with no visable damage, unlike his with clear lines cut into it.
If you are going to replace rings and such you would be an idiot to not replace the VSS. The are common to leak on these cars. I would not be happy if I replaced the bottom end, hones and ringed to have it start smoking in 10k.
The headgaskest are junk. You can not reuse them. The only time you would reuse a head gasket is if the engine had never been run and you needed to remove the head for some reason.
Plastigauge is always a good idea to use. You can use a bore gauge on the rod and bearing but you then need to mic the crank and account for taper on the journal. Or you could just do like you suggested and trust that its good to go and slap it in.

[Austin@STM]

Nothing you just said makes sense. You may WANT to get the machine work done 10/10 but that only works if .010" is enough two clean up any damage to the crank. 10/10 generaly works for a crank with no visable damage, unlike his with clear lines cut into it.
If you are going to replace rings and such you would be an idiot to not replace the VSS. The are common to leak on these cars. I would not be happy if I replaced the bottom end, hones and ringed to have it start smoking in 10k.
The headgaskest are junk. You can not reuse them. The only time you would reuse a head gasket is if the engine had never been run and you needed to remove the head for some reason.
Plastigauge is always a good idea to use. You can use a bore gauge on the rod and bearing but you then need to mic the crank and account for taper on the journal. Or you could just do like you suggested and trust that its good to go and slap it in.

Agreed, never reuse a headgasket, always replace as much as you can while your doing it because it will be easier now than later. Also everything needs to be cleaned. Your best bet is just give the machine shop your motor. They can clean the entire thing, machine anything thats not flat/round and make sure its right to put back together. Their name is on the work so they are going to want to make sure its right, otherwise they look bad. Also if they do the work they will have less of an issue with a warranyt if something goes wrong.

[Assy]

Nothing you just said makes sense. You may WANT to get the machine work done 10/10 but that only works if .010" is enough two clean up any damage to the crank. 10/10 generaly works for a crank with no visable damage, unlike his with clear lines cut into it.
If you are going to replace rings and such you would be an idiot to not replace the VSS. The are common to leak on these cars. I would not be happy if I replaced the bottom end, hones and ringed to have it start smoking in 10k.
The headgaskest are junk. You can not reuse them. The only time you would reuse a head gasket is if the engine had never been run and you needed to remove the head for some reason.
Plastigauge is always a good idea to use. You can use a bore gauge on the rod and bearing but you then need to mic the crank and account for taper on the journal. Or you could just do like you suggested and trust that its good to go and slap it in.
So do i have to go to .25? I would never reuse a head gasket, The only thing on my motor that hasnt been changed are my pistons and rings. How much would it cost to get my block machined?

[CoreyB]

You should take the crank to a trust worthy shop and ask them how far they would need to grind it and whether they think it is worth it. I have no idea on the cost to have the block machined. I am not even sure its nessesary. Every engine job is different and up to the discression of the builder unless you are just hard set on a complete rebuild. I cant really tell you what to do as its not my engine, I am not the one building it, and pictures are not enough to go on.

[Assy]

Yea i just want to get my car running, im going to take the crank within the next week

[Assy]

Exactly, Yes that's usually what I want too.

If the crank is out, stand it on it's end and tap it with a screwdriver or similar.

It should ring like a bell. If it doesn't then it's cracked. Spun barings sometimes end up with a cracked crank. The machine shop should check that first but it's best to check first yourself.
Some noobs posted on another forum that the "ringing" test was the difference between a forged and cast cranks......but they were noobs. All good cranks ring.

i will try that, And i didnt spin my bearing my bearings just went bad

EDIT: rings like a bell

[CoreyB]

Wo you are just full of infinite wisdom Steve. Assy, I gotta bow out of this thread. I wouldnt want a noob giving you bad advice.

[Mike-92RT]

lol what an interesting conversation this has become