compression/timing issues.

[joevanni]

hi nico i got a 91 240sx with 180xxx the motor was swap to another ka24de with lower mileage by previous owner.I did a compression test and it was 120psi all across is this a good compression?.Now the problem is im hearing a tapping slash grinding noise in the head and it also lose high end power around 4-5k the engine still runs and everything works but it loses high end power can it be off timing,I also notice that the upper timing chain guide was missing and it looks like it snap off.All help will be appreciated thanks.

[pungkiteater_671]

120psi for comp ?!? that s*** is LOWWW!!

[liquid_cool]

hi nico i got a 91 240sx with 180xxx the motor was swap to another ka24de with lower mileage by previous owner.I did a compression test and it was 120psi all across is this a good compression?.Now the problem is im hearing a tapping slash grinding noise in the head and it also lose high end power around 4-5k the engine still runs and everything works but it loses high end power can it be off timing,I also notice that the upper timing chain guide was missing and it looks like it snap off.All help will be appreciated thanks.

you may have larger issues here man.....with what you describe and the low comp....im thinking ..not only is it out of time...but you may have slapped the valves with the pistons....now the grinding noise..is your chain..sawing at whats left of your guide...till it gets past that and starts grinding sumpin else more vital....ither way....this is a candadate for a rebuild...or you can run it till it blows.and rebuild a spare....

word of advice.....never ever drop an unproven block into your car with out first...going throu the motor and doing a fresh rebuild of your own....i wish you luck..what ever direction you take on this..

[Rev_D21]

Beautifully explained!

[joevanni]

Beautifully explained!

thanks for everything everybody and the engine was in the car already when it was making that noise,i got the car for 500 buxx and i knew about the problem but i thought it was a simple fix but now the noise got worst i think the valves are slapping the piston so im just gonna swap it with another.

[liquid_cool]

thanks for everything everybody and the engine was in the car already when it was making that noise,i got the car for 500 buxx and i knew about the problem but i thought it was a simple fix but now the noise got worst i think the valves are slapping the piston so im just gonna swap it with another.

its not a total waste thou bro.....it can be rebuilt..and for what ya paid for the whole car..it might be worth it...not only that..but you will get a greater understanding of how your motor works,feals, sounds and runs...this is a huge advantage in the long run...even if you have never rebuilt an engine, its worth the time to learn if only for the advanced knowlage of when an issue arises that is criticle..but not fatal to the motor...or...when you have minor issues that can potentially become like this one...if your timing chain issue was addressed by the old owner early on..you would have a good running car now...so take the time..rebuild this one...and become leet!..

who knows..you might end up the next sought after tuner in your hood...and maybe..it would spark a direction you never thought you would take before...good luck..and if ya need help..we are all here to help ya along the way....aint nicco grand!