HELP! Still have engine noise

[BASS]

I am really stumped on this one. Ive been having engine noise the last 3 months coming through my subwoofer and its driving me crazy. I tried EVERY possible solution with no help in eliminating the noise. My set up is only one amp (300 watt rockford) to one jl audio subwoofer. Everyone told me that it was a ground problem, I tried MANY differnt ground locations and still have the noise coming throught the subwoofer. It drfinitly sounds like alternator noise. I tried (1) ground wire from back of radio harness to the same amp ground in the trunk (no help) (2) Made multiple grounds from the radio harness to the dash opening (no help) (3) made extra grounds from the shell of the actual radio to the chassis (no help) (4) Tried two differnt rca cables (top of the line)(no help)(and made sure they werent kinked) (5) I thought maybe the amp was shot, tried a different amp (no help) (6) Checked the power cable from the battery to the amp (was fine) (7) Tried a noise suppressor, sounded even crappier . I did notice that my actual turn signals go fast sometimes and slow at other times, and that when I put my interior lights on, they flicker somewhat, but at night, the digital dash lights dont flicker, only the interior lights flicker when I turn on the radio(or other accesories for that matter). I am totally stumped on this one and I need help. Could it be that a bad alternator regulator can cause this engine noise through the sub??????

 

[Audiowizard]

You got to love that motor noise!

Check for bad plug wires or high RFI wires. Make sure that amp is grounded to frame and not body including head unit. Also try to disconnect antenna from head to see if it is causing a ground loop. check to see if the power cable and RCA cable are seperated and not run together near metal surface. Check for nicked speaker wire grounded against metal.

I had a Rockford Fosgate Power 1000 brand new out of the box that had a bad pre-amp connection in the amp itself that had bad motor noise when my truck was running. After checking everything that I did, I switched the Power 1000 with my Power 650 and there was no more noise. Try another amp to see if you are getting the same noise, if you are then it should just be in the wiring.

Those noise suppressors do not work. If all your equipment and wiring is good then you should have no noise what so ever. Sometimes a bad alt. can cause motor noise even though it is still charging. Also check to make sure battery has enough juice and the + and - terminals are clean tight and free of acid corrosion.

 

[BASS]

Audiowizard,

My plug wires are brand new (8.5 mm magnecores). My battery is fairly new (high 13's to 14 volts on scanmaster). I used another amp (still same noise). All wiring in excellent condition, nothing binding. Grounds are perfect. I disconnected the power antenna lead, still same noise. For some more info, I originally installed a crappy aftermarket radio to replace the factory one. It was crystal clear when I had that one in. Then I went with a kenwood aftermarket radio, and as soon as I conneceted it, it made that same engine noise. Ok, then about 4 months ago I bought a brand new Pioneer head unit, and when I hooked it up, it was crystal clear for the first month. Then , all the sudden, one day I start the car up and I get that damn noise again!!! I never changed anything and that noise suddenly ocurred. What the hell is going on??!!!! Also, when you turn the key without starting the car, you can hear a slight humming noise coming out of the woofer also. The when you start the car, it makes like a whistle noise out of the woofer, and when you press the gas, it whistles a little louder. Im totally stumped!!!! I think the only thing thats left is that the alternator is bad??????? P.S. I even made sure that my 4 gauge power cable was far away from the coil pack and plug wires. Also, the rca and power cables are on opposite sides of the chassis. I even took the rca cables outside the window and around the car to the amp, still the same noise!!

 

[Audiowizard]

Now it has me stumped!!! May be you should look at the alt being defective! Sometimes its hard to diagnos a problem without seeing vehicle in person. When I had to repair other peoples cars from their mistakes or a proffessional shops mistakes, I was always able to fix the motor noise problem. Most of the time it was a bad wiring job, rarely was it ever the equipment.

Where and how are your grounds done on your head unit and what size ground and location of ground on amplifier? I am starting to wonder if it is an equipment problem! I am still stumped with this one.

 

[GNandTTA]

Unplug the RCA's from the back of the radio and turn on the system. Still have noise? If so, then the problem lies either in the RCA's or the amp. Did you run the RCA's and power wire down different sides of the car? I usually run the power and power antenna wire down the drivers side and the RCA's / data cables down the passenger side. I have seen it many times where EMI noise from the power wire affects the RCA's. If the noise goes away when you unplug the RCA's then it is coming from the radio. Possibly need a filter. But almost every radio nowadays has adequate filtering. Could be a ground loop caused by the antenna. Try to unplug the antenna. If noise goes away with antenna unpluged then it is a ground loop. In that case you may need to electrically bond the passenger fender better to the firewall.

 

[Audiowizard]

See if there is a website for Navone Engineering, The guy is an engine noise expert. I read an article that he did a few years back and the guy knows what he is talking about.

 

[mcss383]

Well go to www.carsound.com Forum. There you will find David Nacone and Richard Clark. The 2 most respected names in car audio.

His personal site where u can get stuff from Navone Engineering.
http://www.davidnavone.com\

 

[Audiowizard]

My best friend knows him and he also owns a GNX, not sure what number GNX though but he parked it next to his dually at one of the compititions.

 

[mcss383]

yeah Richard has a dozen or so GN's and two GNX's. One is ridiculsly fast and the other supposedly still has the plastic over carpet and such.


For those of you who don't know, Richard Clark is one of the reasons that the car stereo market is as big as it is today, he also started the whole stiffening capacitors for car use with his 87 (?) GN. It was an undefeated champion in the sound quality arena back in the early 90's. As of now it is in pieces and he and Mark Eldridge are redoing it. People have been asking to get it back out, but this year he is displaying his 5ft subwoofer....it implodes bread trucks.... Its a beast to say the least......(no rhyme intended...lol)

 

[BASS]

Thanks for all the input guys. Well, today , believe it or not, I noticed that the negative ground cable coming off the battery was not even connected to the engine block!!!!!! I was all exstatic at my finding , saying to myself, " YES!!! I can finally solve the noise problem!!" Well, i reconnected the ground cable where its supposed to go, jumped in my car, turned the radio on, and damn!!!! Still, the noise still there, exactly how its always been!!!!! My only other choice now is to take the radio back out (for the hundreth time and test with another radio. But I have a feeling that the same situation as last time will occur. The new radio may be crystal clear for a couple of months, and then all the sudden im gonna get that damn noise again, as what happened with this radio! Im goin crazzyyyyy!!!!!!!!

 

[GNandTTA]

Just unplug the RCA's from behind the radio and turn the system on. This will tell you right away if the noise is being caused by the radio or not. Are there any signal processors in between the radio and amps (ie. crossover, eq, etc.)? Solving noise problems is not as hard as it may seem. The key is to isolate each piece in the system and eliminate them one at a time. I wish tuning a GN was as easy!

 

[Four-Four-Two]

Check to see if you have your main power wire and the RCA's running near each other on the way back to the trunk. If you can, run the two on opposite sides of the car. My subs made the engine noise like yours, and when i separated the two wires, it went away. Good Luck!