Holy CRAP

Yea, so anyway i've been driving around needing a the typical timing chain replacement for about a month now... been poor, but anyway, i walk into a shop and a guy is going to do it for me for about 600 bucks, yea i know WOOHOO, so anyway he warns me, "dont go speeding around".... but i've been speeding around so i thought pfft... I speed around a little, pick up a friend from work, on my way home i notice this New noise besides the other noise lol.... This one is constant and gets louder/faster as i accelerate... It's a knocking noise.... I'm praying to god it's not a piston mis-firing... But it's a light knocking noise comming from the left side of my engine if you're standing outside looking down at the engine... pasanger side easier said..

Anyway, could anyone give me hope that it might not be my piston mis-firing, like something besides the noise that i would notice?

Thanks for all the help!

FYI - 1990 240sx... 95k miles

Don't mess around w/ it, have that dude check it out or else you can start lookin' for a nice SR swap cuz your baby's SICK, and on deathrow! Seriously just get it to that guy to find out if there's hope to save it. That doesn't sound good at all. Probably is a busted valve, or a valve hitting your piston. That's all I can think of in reguards to your timing chain also being bad... it could have given enough slack to the valve train and something could be hitting, check it out sooner than later cuz in that case, time is a huge factor! Good luck.

The timing chain probably skipped a link and you now have the piston and valve tapping together. This is hella-not good.

yea i know if the piston is hitting the valve i'm in deep shit, didn't think about that even though i've been telling myself all day long about doing the timing chain myself. Yikes...

But if it's hitting the piston, somewhere along the line something like exhuast/fuel would be leaking somewhere, making my car lock up right? or back fire? And if my valve is bent or bends, i have to replace the valve(s) and pistons both right?

Oh yea, and i'm about to bust a loan out tomorrow to fix everything, if the guy tells me i have to start replacing a bunch of junk, think it's worth to keep and rebuild/swap or find a new love? :'( i've fallen in love with my baby, now she's breaking my heart! i just found some local brothers :'(

Bust a loan? Fuck that. Dude go to a junkyard and pull a used KA for about 400(steep price but sometimes you have to do what you have to do) and save yourself the trouble. Don't sink money into this engine. If it is knocking then there is probably some shit that is already broken.

It would still be cheaper to repair the KA then any other option. Keep that new love crap down... you're liable to get jumped in this forum for talk like that!(Just warning you to keep you out of trouble) Nawww, even a rebuild would be good if you had too, a 14 year old KA w/ a nice rebuild would be nice... but if that becomes the case... see what has to be done for a KA24DE swap... I'm not sure what you would need but I'm sure it would be much smoother than a complete SR or RB swap... legal too! Let me know what your mechanic says the problem is, I'm curious to find out how bad it is and what you end up doing.

It would still be cheaper to repair the KA then any other option.

Please justify.

It could be the lifter(s) ticking. To see if it is try reving your engine up a little not in gear...or park if its a auto. And if it still ticks after that then i dont know what it is. The only way i know this is my 3000GT's lift's are ticking (happens alot on thos engines) and it ticks alot and its really scary. But if you rev it up to 3-4k then it go's away till you shut it off again. I dont know if 240's are the same. I'm only trying to help ya out.

This one is constant and gets louder/faster as i accelerate

Does that answer your question?

Yea...on my 3000GT its also constant and gets louder as i go faster just like he said. So no...that doesn't really anwser it...sorry dude.

Please justify.
If he had to replace a piston, or valve, it would be alot cheaper to do so rather than pay someone to yank out his old engine and try to swap an SR or replace it with a new KA... they wouldn't have to pull that old engine to do any of those repairs. Now if he was doing it on his own... then he could save money by replacing the engine. But I don't think that's the case. Am I right? Or am I missing something, please educate me if I'm wrong.

Then your car is F'ed up too. Revving the engine isn't going to fix it. Either you have pre-ignition problems or the valves are tapping. Both pretty detrimental to engine life. Maybe you guys can get lucky and find a small exhaust leak around the exhaust manifold but if the noise is where metal said it was then get it looked at. Don't attempt the timing chain replacement unless you are pretty mechanically inclined.

yea i know better to attempt the chain replace because i screw up then i'll defently be screwing up my valves/pistons... Anyway while i'm in neautral, it still goes along with how high i rev the engine, so now i got 2 noises lol........ :'((((((

Anyway, first would be the timing chain from where the guide has broken and second would be from inside the block guessing the valve or the piston is mis-firing... which would be worse? ... a mis-fire or bent valve..? because to me a bent valve = replacing a lot of crap. and i been to all the local junk yards, most everyone has already poped the valve cover and snagged everything off of every 240.. :-(

www.ebaymotors.com There is usually some floating around on there. You should have a junkyard around that serves as a nationwide locator for parts.

Well dude...i can't help ya out then. I hope you get things worked out with it tho. Good luck.

Well i got an estimate today, it's going to be about 800 bucks for my timing chain, guides, tensioners, and the enclosure (because the chain was cutting into the enclosure making the new noise btw)... so luckly my pistons are OK :-D... Picking it up thursday, ordering injen intake on the following thursday :-D