Just got my swap done as of yesterday...and after making sure everything was tight I have this annoying knock/rattle. Its coming from the middle of the car, right about where the firewall is.

- when inside the car, you can hear it clear as day and slightly when revving (but not as loud)

- when standing over the engine bay, you can hardly hear it if at all.

What could it be? I had a hell of a time getting the rear mount lined up but got it fixed. Dont know if its related or not.

 

Engine?

Car?

Help us help you.

 

sorry about that, its not the engine and i say this because leaning over the motor you can NOT hear this noise...only from the interior of the car...but im not sure whats causing it.

 

Okay let's try this again:

What kind of car do you own, and what kind of engine did you swap into it?

Obviously if it's a SOHC engine there should be no firewall/intake manifold clearance issues, but if you've got an H22A then the suggestions will be totoally different because they can touch the firewall if the mount kit is jacked up.

Also was this car once an automatic and now 5-speed?

Again help us help you

 

OK, sorry again bro...been a long day

Its a 93 Civic EX sedan, 5-speed (always has been), and just swapped in a JDM B16A OBD1 from Hmotors.

 

lets get a bump as i hjave the same annoying noise in my 92 hatch ever since i did my LS swap a year ago whenever i drive it makes a tappin like metal to metal noise. Its not the motor or trans.

 

bump up again for an answer

 

im curious about this too.

 

bump for me again

 

I know this might sound like a generic "let me take a stab at this" type answer, but I've seen loose bolts on engine mounts/brackets cause this noise.

Particularly check the timing side engine mount where the bolt runs through the big aluminum mount and ties it to the chassis - that mount can move back and forth when the engine is revved, and much worse when accelerating or letting off the gas.

The rear engine mount/bracket can also make a "knock" when the engine is revved or acel/decel conditions.

This is important:

Does it do it in neutral, car sitting still, and you tap the gas and it knocks at the same time you hit the gas, or is it only while driving?

 

the rear tranny "T" bracket will make a knock on idle if not bolted down....

chad

i'm in NC if you need someone to take a look at it

 

I might just be retarded but could it be your exhaust? Mine hits my e-bay short shifter and makes the same noise your describing. I know this is a little farther back than your noise but it could be hitting something up towards the motor.

 

to B18C5-EH2, It does it all the time...and it seems to increase with rpms (as far as repitition goes). I can barely hear it in the engine bay. But from the drivers seat...its a persistent knock.

If it was (please no) a rod bearing...i would hear it especially at 3-4k right?

to AnotherEJ, its not my shifter, and even with moving it through all the gears i feel no contact through the shifter itself

 

Well mine is at the shifter but i ment your could be somewhere on the exhaust but that doesnt really make sense if it increases with rpm's so nevermind, i tried

 

It the side motor support mount, where AC bracket and tranny bracket goes into the rubber mount. Those are loose

 

thing is, theres no a/c compressor bracket, and im waiting in the new tranny bracket rubber

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by brockscivic &raquo;</TD></TR><TR><TD CLASS="quote">thing is, theres no a/c compressor bracket, and im waiting in the new tranny bracket rubber</TD></TR></TABLE>

Im not sure what motor you have but all b series uses a/c mount and tranny mount, when i loosen my rubber mount off and forgot to tighten them. I get the knocking sound your describing, i would only hear it inside the car but not while i looking around the engine bay.

 

i know it has a ac bracket from the factory...i took it off

and the tranny support doesnt have the rubber on the end with the 2 holes mounting it to the frame rail

 

it could be catalytic converter heat shield. MInes did the same after the gsr swap

 

checked it already....