engine noise, not ground, please help!!!

[SuckMikeHawk23 10+ year member]

ok, i installed my components and my relay today and now i'm picking up engine noise. i checked the ground, its all fine, what could the problem be? my rcas?? anything else. please list all possible causes of this so i can check it out tommorrow. it wasnt like this til today, so it had to be something i did or installed right?

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[cfurtick 10+ year member]

did you just put in a set of components and a relay for what? we need more info.

i will help if i can

 

[SuckMikeHawk23 10+ year member]

i just added components in my front stage and added a relay to control my remote wiring. since i have 2 amps, i was told to ground the 2 amps to the same point. is this what i should be doing? also, i have a lightning audio cooling fan that worked fine a couple days ago, then i dropped my amp and had it repaired, and now the speakers make noise with the fan. how do i get rid of this? i would like to continue using the fan since summer is coming up. if anyone can tell me how i should run my wires from my amps and fans, then i'd appreciate it. thanks

 

[Nolesman 10+ year member]

A few things I can think of. First double check that ground. The slightest bad connection can be overseen. Two, if your RCAs are close to the ground that can cause engine noise. Three, I see you have an Alpine running your mids/hi but if you changed that to the Fosgate watch out. Fosgates, unfortunately I have found, give you a good amount of feedback when running to your mids/hi. If the problem persists you can always buy a feedback thingy (sorry the name escapes me at this time). It hooks right onto your amp (very small about the size of a jewlery ring box) and is relatively cheap (about $15 bucks). Unfortunately it is not a cure all and can take away some of the crispness of your sounds. Hope this helps.

 

[SuckMikeHawk23 10+ year member]

im stillin using an alpine to run my mids and highs, just a different model, the mrv-f400s. i guess i'll check my rcas tommorrow, but is there anything else that can be causing this prob?

thanks

 

[cfurtick 10+ year member]

I think the feedback thingy nolesman is referencing is a Ground Loop Isolator. This should be used as a last resort though b/c as stated it will rob you of some voltage. Not so important on your sub amp but very important on your mid high amp. Also try grounding your relay at the same spot as you amplifiers. Just run a wire outside your carpet etc to check and see if this works.

Hope this helps

 

[SuckMikeHawk23 10+ year member]

i think i've come to the conclusion that its a problem with the amp. is this possible? because i hooked up my sub rcas and wires to my mids and highs, and my mids and highs rcas to my sub amp, and the problem still existed in the mids and highs rcas and wires. how much should this cost to get fixed? and what exactly is the problem? anyone know?

 

[maylar 10+ year member]

Is this the amp you had fixed? If so they might have neglected to put back some shield or internal ground or something. Exactly what kind of noise are you getting, and is it there even with zero volume on the HU? How about with the RCA's unplugged? Does it change with the amp gain?

 

[installerfreak 10+ year member]

just a suggestion but where might you have your amp mounted if you have it mounted to something that is also grounded to your first ground then you will pick up ground noise i hope i have been of some assistance bye

 

[SuckMikeHawk23 10+ year member]

to maylar: this is the amp i had fixed. the noise does happen when i have my head unit at 0 volume. with the rcas unplugged, theres no noise. and i haven't tried the gain thing yet, but i sure will soon.

 

[maylar 10+ year member]

Originally posted by SuckMikeHawk23 to maylar: this is the amp i had fixed. the noise does happen when i have my head unit at 0 volume. with the rcas unplugged, theres no noise. and i haven't tried the gain thing yet, but i sure will soon.

OK, if the noise goes away with the RCA's unplugged it's either ground loop noise (through the shields) or something getting into the cables (unlikely). You said it's alternator whine, so it's gotta be power/ground related. I'd try relocating the amp ground to another spot in your car. Worst case, maybe one of those isolator thingies. Might be worth asking the service people if they've ever seen that happen before.

 

[beastyle 10+ year member]

You should look at my post about engine sounds from last week.

What to do when hearing engine sounds:

1. Check (and clean) ground points (especially original car ground point)

2. Check bobine hood (its on top of your dynamo)

3. Place caliber LT2 filter

If 1 and 2 dont solve your problem then place the filter otherwise DONT. The filter must be applied on each rca connection from the HU, if you experience problems of sound loss (subs might become a bit powerless) then place the amp that gets losses through the rear speaker ends of your HU

This is (i think) the only good way to solve the problem (assuming you wired the rest ok)

 

[beastyle 10+ year member]

Originally posted by maylar OK, if the noise goes away with the RCA's unplugged it's either ground loop noise (through the shields) or something getting into the cables (unlikely). You said it's alternator whine, so it's gotta be power/ground related. I'd try relocating the amp ground to another spot in your car. Worst case, maybe one of those isolator thingies. Might be worth asking the service people if they've ever seen that happen before.

He's completely right btw, the LT2 is a Ground loop isolator which is exactly the device he described, i dunno if others have it, caliber has it for one and you should expect to pay around 20 bucks for it.

GL

 

[beastyle 10+ year member]

Sorry bout all these posts but i dun like changing.

YES: i'm for 99% sure thats its ONE amp that causes it. If you also hear a bit of scrambling sounds when you simply turn on your radio even when the engine does not run then you can be for sure its the amp. The only thing you could try (and this might sound stupid) is grounding your engine hood.

You should have it even if you would put the volume towards zero

 

[blaupunk 10+ year member]

Where can i get the caliber lt2.