Possible bad bearing...Need help from mature KA experts..

[amolao]

I posted about this before, Now Im pretty sure I have a bad bearing (main or rod). Everytime I start the car I get a 3 second rattle, and is not the chain. Replaced the chain twice with brand new OEM components. Also the oil pump was replaced. Sometimes, I get a loud metallic squeal with the rattle....

Please tell me what will be my best option:

a)Attempt to replace the bearing and take a chance that there is no further damage to the crank or block......

b)Buy a new rebuilt short block ....

These are the different scenarios:If the crank or block needs machine work that brings the price up considerably. Will the new short block be a more viable option then (about $1,000.00)? Will it be even worth to take the engine apart and then find out that the bearings are gone and now I need machine work ($$$$)??

Is a very strong 1989 KA, excellent compression, not burning oil. SR20, RB's, CA's, DE's or other are not an option. The SOHC is bulletproof and perfect to my daily happy driving style. And relatively cheaper and easier to work on than other engines out there (including the DOHC...)

Sorry about the long post and appreciate any help...

[s13rb25det]

does it just make this noise at start up? or all the time? I might want to check your powersteerimg pump/fluid if it is low or wprn it can sound a lot like a bad bearing.

[JNM240]

Bad or spun bearing would make noise all the time, not just on startup. remove all your accessory belts and start it up, that way u know its not the AC, PS or WP making noise.

[ShionS14]

If it is something to do with engine and not one of the accessories it would be better to take your block to a machin shop. i know here locally you can get a block checked for leaks cleaned and checked for warps for about $200 bucks. a new short black will cost you over a thousand bucks and if you buy a used one then you would still need to have it checked out.

[gumby74]

The original KA E in my car was shot 6 ways from Sunday. As it was not my dd, I pulled the engine, removed accesories and head dropped off the block and head at a machine shop for a rebuild. The short block came to $400 w/new bearings, pistons, full gasket set and thorough cleaning. The head came out to $100. Valve job w/new seals, surface was trued, lifters were cleaned. After timing chain, oil pump, clutch kit and odds and ends, she came out to roughly $800 assembled and installed by me at home.

The moral of this story: If its not the bearings now, it will be at some point. Find you a rebuildable core, get that crank worked and get some Clevite's. That is assuming your engine gives you the time, and you have the space/resources/ability to do this.

[amolao]

I will check by taking the belts off, but Im pretty sure there is a bearing going out and it only rattles at startup due to the initial vibration and lack of timing engines go thru before they settle down and get in sequence...

http://www.rpmrons.com/Nissanengines.html

The link above is just for example purposes, If I go with something like this, what else will be required to be done during the final assembly ??I do have excellent facilities (military auto shop)but my time is limited. There are local machine shops in the area but I'm not sure of how profficient they are on Nissan engines....

[ShionS14]

well it depends if you go with the short block or the complete engine. if you get the complete engine you would just need to pull your old one out removing all the accessories. i would pull the transmission out and inspect the gears and problably just put a new clutch and flywheel in (might as well while it's out) then drop everything back in, bolt up your accessories, plug in all the harnesses, fill up the fluids, prime the oil pump and check for circulation and then a compression test. after that fire it up and go through breaking it in. if you do just the short block you will of course have take your old head off and put it on your new block.