No Idea. Help needed

[Emeru]

So sometimes when i throw third or 4th my car does this vibration.. and sounds kinda like a misfiring system..

It also does it when I downshift 3rd and sometimes 2nd.

Anyone have any idea on what it might be??

i drive a 89 240sx KA24E. if that helps.

 

[go7roo7]

well vibration could be caused by worn engine and tranny mounts, so check that.

missfire... would be post detonation if it sounds like a sudden pop in the exhaust when you downshift.

downshifting alot usually fucks the engine mounts, especially since alot of ppl do it at high RPMs for the sound, unaware that when you do it, you are actually jolting the shit out of the mounts.

worth to check.

hope i helped

 

[mark_fox]

Sounds like mounts to me as well, usually any sort of vibration at specific points is usually because of crap like that.

 

[hhn2002]

.....
downshifting alot usually fucks the engine mounts, especially since alot of ppl do it at high RPMs for the sound, unaware that when you do it, you are actually jolting the shit out of the mounts......

yes well drifting jolts the shit out of everything! lol:laugh:

 

[Emeru]

well vibration could be caused by worn engine and tranny mounts, so check that.

missfire... would be post detonation if it sounds like a sudden pop in the exhaust when you downshift.

downshifting alot usually fucks the engine mounts, especially since alot of ppl do it at high RPMs for the sound, unaware that when you do it, you are actually jolting the shit out of the mounts.

worth to check.

hope i helped

well usually when i downshift i always rev match so the gear goes in easier..

but its not really a pop.. its more like a misfire noise from all the vibration..

ima check the mounts out see whats up.

 

[Chigga311]

Does your car hesitate at all??
If so check your timing and ignition components.

Check the ecu if you have any codes.

Maybe try running a higher octane gas for a tank.
If that makes it go away then you probably have carbon build up in the cylinders causing detonation under high load.

And check you engine mounts.
Get a set of nismo's if you still have the old @ss ones.

 

[Emeru]

well i checked the mounts they seem fine..

but i noticed if i shift real fast it does no vibration..

btw it only does it sometimes not always..

and i run premium all the time. and nope car does not hesitate.. ima call my dad up ina lil see what he thinks it can be.