Fighting Noise In A 2018 Honda CR-V

[nickwilson159]

I've been fighting noise in my new 2018 Honda CR-V ever since I had the radio installed - see video below:

https://www.youtube.com/watch?v=THYdX08vCmU

I had the radio professionally installed by NYCOMCO, including an NMO mounted Comtelco 1/4 wave (drilled a hole in the roof) and Comtelco Micro Loss 900 coax. Removing the antenna eliminated the noise, but just to be safe, I ran a second ground to the seat bolt - no changes. I then installed 4 ground straps along the exhaust, tailgate-to-body, hood-to-body, engine block-to-body, and radio body to seat bolt just to be safe - again, no changes.

The next course of action were ferrite beads, which were applied to the coax and various wires around the engine bay. The beads on the leads to the coil packs were the ONLY thing that made a dent in the noise of everything I've tried. Unfortunately, as the leads to the coil packs were so short, they aren't exactly mounted as they should be - and most of the wiring is still encased in plastic.

Any ideas on where to proceed from here? Some Googling made mention to using 3M copper tape to wrap around the offending parts, but I'm not sure if that'd actually work or not.

Thanks in advance...

 

[mmckenna]

Removing the antenna eliminated the noise, but just to be safe, I ran a second ground to the seat bolt - no changes.

That indicates that the vehicle itself is the issue. If removing the antenna eliminates the noise, it means the vehicle is emitting enough RFI that the antenna is picking it up and giving it to the radio.

The beads on the ignition coils is a good approach. Not sure how much more you can do. Some vehicles just seem to be noisy. There's been similar issues with some Dodge products.

 

[chief21]

To me, it sounds like you might have two (or more) separate noise sources. Have you tried ferrites or a quality noise filter on the DC feed? Another possibility could be incidental RF from the vehicle computer(s).

 

[scottyhetzel]

Seat bolts are bad due to painted bolts...try grounding by cleaning paint and using 1/4 bolt .
Use a tone probe to find the source. Ground the alternator too. Sounds like an imbalance between the Antenna ground and unit. Trying grounding the unit to chassis. What happens when you lift the ground on the radio? Try moving radio ground somewhere else.

 

[nickwilson159]

Tried running a ground direct to the battery along with a Kenwood KLF-2 DC Line filter, and went so far as to use copper tape to cover the exposed parts of the coil packs. These two actions, at first, eliminated 95% of the noise. The next day, the noise was back and as bad as ever with no changes made - engine temperature, moving vs. standing still, accessories on vs. off, nothing changed or seemed to make any difference. Some days, the noise is almost undetectable, other days it's overwhelming full quieting channels.

Will try grounding the alternator next and trying a different ground for radio chassis to body.

 

[nickwilson159]

One thing I forgot to add is that this noise is present on a portable as well.

 

[belvdr]

One thing I forgot to add is that this noise is present on a portable as well.

If you mean on a battery powered unit, then it is arriving on the antenna. If you have tried all accessories, I'm not sure what else you can do.

 

[KK4JUG]

Another point of view: if the radio was "professionally installed," I would think they would have tested it, found the noise and removed it or at least lessened it.

 

[northzone]

Take a portable tuned to the frequency were you seem to be having the worst noise. Then with the portable in the AM MODE and squelch open, hunt around the vehicle for the source of noise. Remove the portable antenna if the signal is too strong. Car computers, anti-lock brake modules, I have seen noise from many things.

 

[nosoup4u]

I owned 3 Honda's in the last 12 years, 2005 CRV, 2009 Accord and a 2010 CRV. All 3 would throw noise on my scanner/2 way if I was using the duck. Using an external antenna did solve the issue, at least in my Accord.

 

[12dbsinad]

Another point of view: if the radio was "professionally installed," I would think they would have tested it, found the noise and removed it or at least lessened it.

Why would it be the installers responsibility for noise generated by the vehicle? If their install is done at pro specs, outside sources of interference shouldn't be their problem. Sure, they can look at it, but I would hope not for the original install price.

It isn't as easy as just installing a DC filter. This noise is RF generated. Sometimes it's just impossible to totally cure. Welcome to new age vehicles..

 

[KK4JUG]

Why would it be the installers responsibility for noise generated by the vehicle? If their install is done at pro specs, outside sources of interference shouldn't be their problem. Sure, they can look at it, but I would hope not for the original install price.

It isn't as easy as just installing a DC filter. This noise is RF generated. Sometimes it's just impossible to totally cure. Welcome to new age vehicles..

If the radio is not usable, why install lit? To me, it's a part of a "professional" installation. If it's installed by someone who installs stereos in cars, that one thing. If it's done by a :"two-way radio shop," as they're sometimes called, it should be ready to use out the door.

 

[12dbsinad]

If the radio is not usable, why install lit? To me, it's a part of a "professional" installation. If it's installed by someone who installs stereos in cars, that one thing. If it's done by a :"two-way radio shop," as they're sometimes called, it should be ready to use out the door.

Because Two way shops don't typically test for RFI prior to installation unless they are getting PAID to do such. There are WAY to many variables including aftermarket equipment. Testing for RFI isn't easy. You'll need to drive the vehicle in all conditions; day, night, hot, cold, different functions of the vehicle on/off, etc, etc. Even a 12V to USB phone charger can wipe out the lower bands.

I don't know of a shop around that guarantees no RFI on a run of the mil mobile install..

 

[KK4JUG]

Because Two way shops don't typically test for RFI prior to installation unless they are getting PAID to do such. There are WAY to many variables including aftermarket equipment. Testing for RFI isn't easy. You'll need to drive the vehicle in all conditions; day, night, hot, cold, different functions of the vehicle on/off, etc, etc. Even a 12V to USB phone charger can wipe out the lower bands.

I don't know of a shop around that guarantees no RFI on a run of the mil mobile install..

I'm old and I guess, old-fashioned. I sort of assumed customer service. My bad.

 

[captainmax1]

Did you try attaching a mobile mag mount antenna with a 12' or more cable to back of the radio and moving the antenna around or away from the vehicle? You probably did this first day but was just thinking.

 

[12dbsinad]

I'm old and I guess, old-fashioned. I sort of assumed customer service. My bad.

If anything is the fault of the install, then that is where customer service kicks in, if that's what he paid for. It SHOULD be done to the highest of standards if it's a pro shop.

Long gone are the days of just a bad cap and rotor, or leaky spark plug wires causing ignition noise. It's a whole different ballgame now with RFI, and that includes everything, not just vehicles.

A shop would just simply go out of business, or charge such a high rate they wouldn't get any business trying to chase outside sources and predetermine the existence of such and guaranteeing it with every year, brand. make and model vehicle.

 

[nickwilson159]

Well, some more testing, and I have a hypothesis now. While parked in the same spot for over 24 hours, engine cold both times, the noise was gone yesterday (75 degrees & cloudy yesterday morning) while it was present today (sunny & 82 degrees late this afternoon). After driving it for a bit, the noise disappeared. Heat seems to be the only common factor - messing with accessories had no effect, and the noise is present on portables as well. I'm wondering if there's a hairline crack in one of the ignition coils that I'm not seeing, or perhaps something on the PCM itself.

Some snooping with a cheap FM radio in the engine compartment yielded noise around the coil packs and the leads to the PCM (to feed the tachometer). Being that the leads to the PCM are buried in split loom and go through a few junction boxes, I figured I'd tackle the ignition coils first. Hitachi just came out with aftermarket ignition coils for this engine - they & Standard/Intermotor/BWD are the only ones offering aftermarket versions, and Hitachi is the only one that actively advertises RFI suppression. While I can't find any reviews on their products specific to RFI, reviews in general on Hitachi coils are very good - seem to be very solid electrically, often exceeding OEM performance. I'll see if they help any.

 

[nickwilson159]

Regarding the professional installation & RFI, I have to agree with 12dbsinad on this one. There are tons of variables that can cause RFI, and many have nothing to do with the install itself. The install was done in accordance with Motorola's own recommended practices; they've also done identical installations on hundreds of emergency vehicles with no ill effects. In this case, being that the ignition system is suspect, it really has nothing to do with their installation - heck, I wouldn't be surprised if they pointed me to a mechanic instead if I tried to take it to them to alleviate the issue.

 

[RFI-EMI-GUY]

are those ferrite beads sized properly for the coil wire? I see one that looks like the halves are separating. It the ferrite halves have an air gap, they are not gunna work.

 

[RFI-EMI-GUY]

Well, some more testing, and I have a hypothesis now. While parked in the same spot for over 24 hours, engine cold both times, the noise was gone yesterday (75 degrees & cloudy yesterday morning) while it was present today (sunny & 82 degrees late this afternoon). After driving it for a bit, the noise disappeared. Heat seems to be the only common factor - messing with accessories had no effect, and the noise is present on portables as well. I'm wondering if there's a hairline crack in one of the ignition coils that I'm not seeing, or perhaps something on the PCM itself.

Some snooping with a cheap FM radio in the engine compartment yielded noise around the coil packs and the leads to the PCM (to feed the tachometer). Being that the leads to the PCM are buried in split loom and go through a few junction boxes, I figured I'd tackle the ignition coils first. Hitachi just came out with aftermarket ignition coils for this engine - they & Standard/Intermotor/BWD are the only ones offering aftermarket versions, and Hitachi is the only one that actively advertises RFI suppression. While I can't find any reviews on their products specific to RFI, reviews in general on Hitachi coils are very good - seem to be very solid electrically, often exceeding OEM performance. I'll see if they help any.

The coil packs could be fine but the rubber boot between the coil Pack and the plug can be arcing over. Look at the coils firing with the area darkened like inside a garage at night.

It also could be the electric fans, They go bad and can make plenty noise. Do this:

Turn off the AC does it stop?

Temporarily disconnect the AC and engine radiator fans (Danger! keep AC off!) Does it stop?