Engine Noise CB Radio [SOLVED]

2003 Xcab 4X4 6 cyl, bone stock, no mods

The question: Does anyone have solutions to engine noise coming through their CB? It's not "alternator whine," it's a low bap-bap-bap with the RPM's of the engine. I know it's leakage through the injectors, ignition or ECU, and have done a lot of research (see below) but one of the scary conclusions is some vehicles engine noise will just not go away.

The setup:
I've only started the radio up once and have not done any of the common solutions below. I haven't even messed with the ANL switch (yeah duh,) which will be my first thing. Don't want to resort to squelching it out.

- Cobra 19 29 LTD Classic
- Bumper mounted 4' FireStik with HD spring, continuity all tested OK
- Ground strap on antenna mount
- Coax entry point in the cab is under the rear seat access panel. I cut a new hole with a grommet to the left of the taillight loom because . . .
- Coax does not cross any major wires, no loops in layout, it would have fit through the grommet for the taillight loom but trying to eliminate crossover
- Here is where I got lazy and may be the source of the problem. Power is soldered into one of the key-on lower dash accessory plugs. It is recommended to run the CB power directly to the battery, negative directly to frame, I will do this if filters/chokes don't work.
- SWR is tolerable on 1, 40, and 20 (less than 2, has nothing to do with the interference.)

If connecting direct to battery/frame doesn't work, I'm looking at the Workman NF40 suppressor or similar for the power, and ferrite snap-on chokes for the coax. Does anyone else have CB issues with the Taco's?

Hopefully it's not vehicle related. I read a 4 page thread of one poor guy with a Uniden, his was a Jeep. He even applied expensive equipment to read the noise sources, and tried his with a spare battery in the passenger seat, interference just wouldn't go away and concluded that some radios and some vehicles just have issues. Hoping it's not the case with the Taco's.


Edit: ANL knocked it right out, along with all the weaker signals. Not a great option. Workman filter and snap on ferrite cores on the way.

 

Where did you ground the unit? This sounds like you need a proper ground for the it.
I had similar issues with a previous vehicle's CB install. I tried to use a bolt on the transmission tunnel for ground...got the same results as you.

After running a proper ground to the frame, no issues.
(The unit's power was direct to the battery.)

Cheers

 

Thanks, you mean the antenna or CB itself? Presuming the CB case, not grounded but I have heard this might help. I did test continuity between the case and truck's frame/body/ground, that part is good. Was just about to go string a wire directly to the battery, it is likely that.

Antenna grounded to to cleaned bolt where tow package bolts to frame.

The best news is, you got it to go away, which was my biggest concern. Apparently there are some applications where it doesn't, the noise from the vehicle just can't be filtered with a given radio.

I went ahead and ordered the Workman filter and an assortment of snap-on ferrite cores, will apply those when they get here.

 

Grounding the CB itself might help, and doesn't cost more than some wire and time.

Cheers

 

Tried, no change, but here's what did work:

Ferrite cores on each end of the coax cut out about 50% of the engine interferrence but still there.

Adding the Workman NF-40 cut it out completely, barely any difference between engine on and engine off.

Now I just need to get in the habit of using it. :-D