05 Honda Civic EX rough idle
 

Hey guys hoping someone can help me.....

All my problems started about a month ago....
my CEL came on so i took it to autozone to run a code test.

First i got
p0420- catalyst system efficiency below threshold (bank 1)
I replaced my cat converter, light went off.


2 weeks ago CEL came back on and i was read
P0300- random / multiple misfire detected.
P0301- Cylinder 1 misfiring
P0302- cylinder 2 misfiring
P0303- cylinder 3 misfiring
P0304- cylinder 4 misfiring

I replaced the spark plugs and my light went off about 15 miles after driving it.


Last Friday I noticed my car vibrating very heavily so i decided to check the engine mounts. Sure enough the front one was bad. I just finished replacing it and i'm still having a very bad heavy vibration :( I made sure none of the other 2 are broken and they are not.


The vibration is very bad at idle now and it has no CEL on.
Now i'm being told i might possibly be a bad spark plug (again) / wires, my fuel injectors or my O2 sensors. I decided to buy a Actron Scanner to do some testing
Hoping you guys could help me with the readings

Attachment 114497
Attachment 114498
Attachment 114499

[YOUTUBE]https://www.youtube.com/watch?v=P_oO9xV4rcg[/YOUTUBE]
[YOUTUBE]https://www.youtube.com/watch?v=r9WzFYVY_Ds[/YOUTUBE]

Re: 05 Honda Civic EX rough idle
 

Dude, does your engine sound like a coffee can full of marbles or rocks? It sure sounds rattly in the background of the videos.......

Get some video of that in the engine compartment, and the noises at various RPMs.


Check the oil......Did it run very low or nearly empty?

Re: 05 Honda Civic EX rough idle
 

I believe the noise (that you can hear in video)
is coming from my input shaft bearing. It goes away when I slightly press the clutch. I'll get some video though and post it up.

My oil level however is fine it's at the max line. I did an oil change about 2,000 miles ago. I have never ran the car my self with low oil I always make sure my levels are good.

For the record my civic just hit 175,000 miles

Re: 05 Honda Civic EX rough idle
 

Attachment 114494
Attachment 114495

Re: 05 Honda Civic EX rough idle
 

Ok, just so long as the noise isn't in the engine.
Sounded unusually noisy in the background.


Misfire codes haven't returned?


Is this a running problem, or just a vibration? Noise?
Shaking? Vibration from the engine being transmitted through the body?
Exhaust hitting the body? Exhaust heat shields rattle? Wrench got dropped, now wedged between the engine and the frame? Lotsa possibilities.

If the problem is at idle, I'd probably try to figure out if it might be a single cylinder fault:
Let it idle, unplug #1 coil and see how the engine idles, for a few seconds, let it stabilize.
Mental note how it idles.
Reconnect the coil.
Repeat for the other 3 cylinders, see if one cylinder has much less effect than the others.



If just vibration, aftermarket engine and trans mounts can be much harder than stock. They can cause a lot of somewhat mysterious vibration complaints at the shop.

Neutralize the mounts? Check it out here: http://honda-tech.com/showpost.php?p=36669793&postcount=16

Re: 05 Honda Civic EX rough idle
 

Misfire codes have not returned

I have mainly noticed it when its idle, but it does do it when im on the road and cruise it on neutral. The whole engine shakes / vibrates the body badly. My exhaust did fall off from the back due to it vibrating so much. i had each point re-welded and reinforced. my exhaust heat shields were also rattling so i took them off.


Im going to try testing each cylinder as you mentioned and post what i find.... ill also double check to make sure no tools fell anywhere

Ill post a video of my engine shaking first thing tomorrow morning when sun is out

Re: 05 Honda Civic EX rough idle
 

Haven't tested the coils yet, but i think i might have found the issue....
My civic's starter is only on with one bolt! and someone stripped the aluminum thread :_doh:.

Apparently that was also the loud noise it was making cause i inserted a new bolt started it and it stopped shaking so bad and making the noise.

Im going to drop my tranny this week and rethread the bolt, and possibly change my input shaft bearing and clutch while im at it.... i was told my bank1 sensor 2 O2 sensor might also be done since its so much negative volts... ill keep everyone posted on what i fix and if it stops shaking so much...

Re: 05 Honda Civic EX rough idle
 

O2S1/2?
I don't see O2 sensor #2 negative voltage here
Attachment 114492


Ignore it.

Your engine is not running and the sensor is not up to operating temperature in this picture.
And you have no codes related to it.


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-

If you meant the other pic showing O2S1/1??
Attachment 114493

Ignore it too.
That's not volts, and that's not an Oxygen sensor.
It's an Air/Fuel ratio sensor and it displays in milliamps.
It looks fine for an engine that isn't running IMO.

And there is no code stored for it.




Watch what the sensor values do when the engine is running and everything is up to their operating temperatures. The values displayed will be very different.


HTH

Re: 05 Honda Civic EX rough idle
 

Thanks @ezone ,

I need to fix my starter bolt before i can keep testing but ill keep you and everyone updated once i can start my car properly again
I'm hoping its just my starter that was moving out of place and making it shake/vibrate cause it seems like it was getting stuck open on flywheel

(probably by Wednesday or so i say)

Re: 05 Honda Civic EX rough idle
 

(95 Civic EX) I purchased a cheap compression tester (ebay, China) for a motorcycle. when I got it, it wouldn't hold the reading or read very high. So, I tried it on the Civic, ya know, because it's a Civic and same thing. Bought another one from Harbor Freight (junk) and it too wouldn't read very high or hold the reading in the gauge. Bought a third one from Sears and got good readings across all four cylinders, average 160psi
But in doing this I think I may have damaged plug wires, (or something else) because now I have a rough idle. Wasn't rough before I did the 3 compression tests. So, does anyone know the proper reading I should get when testing plug wires, or should I just do the shotgun approach and replace relevant stuff that hasn't been replaced on the car yet? i.e. plug wires, cap, rotor, etc.
:help:

Re: 05 Honda Civic EX rough idle
 

Individual cylinder results are far more important than an average.
10% variation between cylinders is the max allowed.

And 160 seems low, did you do the test on a hot engine? Did you keep cranking until the gauge maxxed out?


If you want to ohm test, it's roughly 10k ohms per foot.

If you want a real world test, see if spark is reaching the end of each wire. See how long the bolt of lightning can be made, how far the spark can stretch across an air gap. I like to see a good 1/2 inch of spark at the ends of the plug wires.

HTH

Re: 05 Honda Civic EX rough idle
 

I bought a set of plug wires for my '92 Toyota Paseo after narrowing the problem to them... and the difference in drivability and fuel economy was amazing. Anything older than ~10 years should be replaced with OEM wires... if you live in the Southwest US, half that.

Cap and rotor should be replaced together, and more often where there are seasons... moisture getting in the cap and corroding will affect driveability. I did my Paseo in WA every year. My OEM Denso cap/rotor were visibly better-made than anything aftermarket, so got them at the dealer (so sense stressing over $10 difference when it comes to drivability/mpg, esp these days).

Mind you... a few months after that incident, my OE coil gave up on me. So if yours is OE... I'd save for another factory one as well. If your coil gives up on you in the middle of nowhere, it's a hassle.

Using non-OEM plugs in my D17A2 7th gen is bad... but on your older 5th gen it's less picky. But do make sure contact between the plug head and the inside of the plug wire end, is snug. I helped this clueless '97 Accord owner in my apt complex with a drivability problem... and his plug leads were so loose on the plugs they may as well've been the wrong size -- no 'click' when you pushed them on the plug. Crimped the lead contact(s) with some pliers... and voila, no more idle problem. ;)