# I need some help, someone please give me some advice!!!



## mybeloved240 (Nov 6, 2006)

ok, here is the thing, i have a 92 240sx, and i love it. When i bought it i new it was gonna be a project car, i didnt care. the motor is totally new, i got it rebuilt. it was great for the first month, then it started knocking. When i got the rods, i only got 2 new ones, and the other 2 were old. well anyway, i have been callin around all the shops and they keep tellin me that i either need to get a new motor ($3,000 and up) or buy a new car. I dont want to buy and new car or a new motor. i just want to fix the problem. they say that the crank shaft is prob messed up and the rods... what do yall think???? i just want my car again, its been 8 months...


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## Nismo240 (Jul 24, 2004)

for $3000, you could get an SR. or you could rebuild it yourself.


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## rogoman (Dec 16, 2004)

What ever it cost you to get it rebuilt the first time should be about the same this time around again unless there is some major damage. There's nothing wrong with using the old rods as long as they are in good shape.

It's most likely that whoever did the rebuild the first time, screwed something up during the buildup causing the early failure unless you failed to maintain the proper oil level or ran the hell out of it during break-in.

Here are some basics of engine building: 
- block boiled and magnefluxed.
- measuring the cylinders for out-of-round and taper then determining if the cylinders need only to be honed or bored to the next oversize. 
- the crank needs to be magneflux and straightened then the journals measured to determine if they need to be reground to the next undersize. 
- the rods need to be magnefluxed and straightened.
- if the block had to be honed or rebored, new pistons will be required.

There's a lot to reassembly. Measuring piston-to-wall clearances, measuring rod/main bearing clearances, wrist pin clearances, rod side clearances, crank end play, setting up piston ring gaps. The list goes on.


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## mitch1988 (Oct 17, 2006)

if the knock is coming from the bottom end you probally are going to want to send out your crank to get balanced..plus do all of the above....plus a HINT for next time never but used internal parts into your car. they could be out of round ar tapered


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