spoolin08

so i recently put new pistons rings and rod bearings. in my gsr it is boosted. after the rebuild it ran great for the first couple hundred miles and shortly after the 500 mile oil change it started acting up when you start it the oil light comes on and it knocks 2 or 3 times then when it idles down it sounds fine and idles great then when you rev it up the oil light will flash and it will knock a couple times. my first thought was the oil pump? but it seems like they are perty straight forward and if they were to go out they would not provide pressure at all. (just a guess) possibly a cloged oil pickup from assembly lube? does anyone else have any ideas or advice? thanks for the help. also if there is already a thread about this i tried searching it and couldnt find anything.

rich7777

You need to pull the sump off and inspect all bearing. You'll probably find a few bad rod bearings. Somethings not right with it.

spoolin08

even if it has bad bearings that doesnt explain the oil light coming on like its not getting pressure does it?

iamthefollower

It sounds like it may be something going on with the main bearings, I would check it and everything. The oil light coming on is explained from bad bearings, you get oil pressure off of the bearings.

rich7777

Yes it would. If some bearings are bad then the oil pressure will drop causing the oil light to come on. It sounds rod bearing related to me.

viper_boy403

iTrader: (1)

Pressure is the resistance to flow. Your oil pump just flows oil, it doesnt pressurize it. The bearings create that flow resistance, and if they are too loose, you get low pressure. What bearing clearances are you running on those bearings you replaced?

BigMike0147

I'm curious to hear the bearing clearances you used as well. I'm putting together my first build right now too and I don't want to over shoot it! LOL I know my b18b will be a little tighter, but I just want to see what you ended up running yours at

rich7777

Well put

civickiller

How did u measure the clearances on the bearings ?

spoolin08

i just ordered standard rod bearings from the local parts store and its been quite a while so i dont know what the clearances are but im assuming that my best bet is to take the pan off and inspect the rod and main bearings and see if one is spun? if that is the case do you recommend replacing all the bearing if so what size should be used?

civickiller

You have to plastigauge it to find the correct clearances for the bearings

First you also gotta see if there's any damage to the crank which requires machining

is it stock rods and crank?

spoolin08

yes its stock rods and crank do you recommend just taking the rod caps off and visually inspect the crank and rods and make sure the the oiling holes are clear and its not torn up

viper_boy403

iTrader: (1)

if you're getting knock, you're going to want to check the rod journals on the crank with a micrometer to ensure they're not out of round. The first step is check all the bearings and journal surfaces, then go from there. Whatever you do, stop running the engine

civickiller

Just incase you were wondering, You have to check all rod and main bearings

if I were you, I'd have a machine shop check out the crank and rods

rich7777

If it was me i'd pull the engine out and strip/inspect it. You can guaranty you have bearing material everwhere. Also OP, i'm not sure what bearing you went for but genrally you want to make sure they are a decent Tri metal bearing. OEM, ACL, Clevelite, Daido are good bearings... So look into them.