Engine noise from hell

[awagner777]

Alright, Anyone know where I could be picking up engine noise from? I ran 4 ga power from the underhood fuse panel, under the car, then up into my trunk where my beefy Alpine Amp lives. Now, i doubt the ground, because it's a short, 4 ga cable that i have grounded in about 4 diffrent spots. All of them gave noise. Now i have the power wire run behind the coil, do you think maybe that is it? Lemme know what yous guys think....

[pimp86LX]

hmm what kinda plugs are ya running? could be wires...make sure its not near the coil of course.....uhmm got a multi meter? try tapping in at different spots with the meter to measure noise (if your meter can do that)
thats all i can think of

[awagner777]

champion plugs....should i move it from behind the coil.....my options are limited. See picture.

[pimp86LX]

hmm that fuse is kinda close to the coil...but i'm not familiar with the coil itself so i couldn't tell you for sure if thats causeing the problem

[89accordlxi]

I don't know if this has anything to do with it, but why not just connect it straight to the battery terminal instead of the black box. According to the photo, it looks like the wire is running pretty close to the coil. That might be the problem. On mine, I just ran my power wire along the intake tube and fastened it with zip ties. See if that helps. Plus, why are you running the wire under the car instead of through the fire wall. There should be a factory hole with a rubber plug covering it on the fire wall behind the throttle body. Then just running along the driverside floorboard to the trunk.

Thats all the suggestions I have.

Good luck!!

[awagner777]

Well I'll tell ya, after running an antenna cable (for my handsfree celly kit) two sets or RCA's, two sets of 16ga speaker wire, there isnt much room for a 4 ga power lead. Under the car was the most logical. and as far as that goes it works very well. As for the question about the mount point, I have put it both places, on the fuse box and the battery terminal. I like it there better, its out of the way should i need to swap the battery.

I am begning to think that the coil is the culprit. I'll check it out. thanks guys

[Bobs89LXi]

Suggestions:

1. Connect the power cable directly to the battery or buy a power distribution block. Depending on the amp you are running, you could be pulling as high as 50 amps or more of current. Granted you have an inline fuse on the power cable, but the terminal block on the fuse box may melt before the fuse blows.

2. I agree with 89accordlxi. Run the cable through the cabin. Drill another hole in the firewall and use a rubber grommet if you have to. Running the power cable outside, under the car could also be part of your noise problem. It is acting like an antenna, picking up any and all stray electrical noise from your engine. In the cabin, the body of the car acts as an EMI shield.

3. Place the ground as close to the amp as you can. If it is in the trunk, drill a hole in the chassis and attach the ground lug using a large sheet metal screw. Better yet, if you have the means to, your best bet would be to weld a threaded stud to the chassis on which to attach the ground lug.

4. Run your speaker and RCA cables as far from the power cable as you can. Although you won't pick up engine noise from the power cable, it is a good source of alternator noise.

[88lxicoupe]

to me this sounds like the best solution
run ur power cable accross the firewall and there should be a rubber gromet on the drivers side under the steering wheel. its thick so slice an X in it and run ur power cable threw it and run it under the carpet to the trunk. and second u can not run ur pre out audio cables next to ur power cable run them down the other side of ur car. this will reduce ur engine noise (i hope) lol

[shepherd79]

if you are running power and sound cables on the same side. it can cause the problems.
i had power and cable from HU running on the same side. i was getting some noise problems. just run power on the other side, and everything else on the driver side.
coil has nothing else to do with it. make sure you have spark plugs with resistors inside, i think most of them have this feature.
but i can swear ran the power on the other side and you should hear the diff.