2018.5 Seneca – S2RV Chassis Wind Noise Fix

[SloPoke]

I'm not all too excited about putting Silicone or RTV on the cowling of my Seneca, I know how that stuff makes taking things apart in the future a tough challenge.

Question for Rusty... What do you think about injecting expanding foam insulation ((INSIDE OF A PLASTIC LINER)) into that cavity? It would be molded to fill the contours inside of that, but could be removed when that cowling panel is removed. If there were any extra foam that squished out in an undesired area, it could be trimmed after curing and then put back. Much like delicate electronic systems are shipped in a box.

[dramo77355]

RTV Silicone (Room-Temperature-Vulcanizing silicone) is a type of silicone rubber made from a two-component system (base plus curative; A+B) available in a hardness range of very soft to medium--usually from 15 to 40 Shore A. RTV silicones can be cured with a catalyst consisting of either platinum or a tin compound such as dibutyltin dilaurate.[1]

It is a silicone sealer typically sold in auto parts stores to seal windows and make gaskets for things like thermostat housings on cars. It comes in small tubes and large tubes similar to calk tubes for the home.

Permatex 82180 Ultra Black Maximum Oil Resistance RTV Silicone Gasket Maker, 3.35 oz. Tube is one of my favorites. Get the large (calk type tube) at ORiellys Auto Parts, as it will take a lot if you only seal the holes. If you go with taking off the panels and using the foam sealer, it will take less.

[RVermont]

Originally Posted by SloPoke

I'm not all too excited about putting Silicone or RTV on the cowling of my Seneca, I know how that stuff makes taking things apart in the future a tough challenge.

Question for Rusty... What do you think about injecting expanding foam insulation ((INSIDE OF A PLASTIC LINER)) into that cavity? It would be molded to fill the contours inside of that, but could be removed when that cowling panel is removed. If there were any extra foam that squished out in an undesired area, it could be trimmed after curing and then put back. Much like delicate electronic systems are shipped in a box.

I was thinking the same thing. Use minimal expansion foam in a bag would make perfect fit. I used some window foam, I cut that and inserted it into the cavity. I used non hardening rope caulk similar to plumber's putty to seal the fiberglass parts and keep them from rubbing. Seems to work well so far. I did not run the foam all the way down as it appears to be the drain cavity from some of the hood openings .

We drove about an hour and a half friday and we both agree that the cab was quieter. So , well worth the 10 minutes each panel took. The hardest part was finding a socket to reach in between the door and the chassis frame to remove the two screws .

Thanks for everyone's help on this.

[Rustynuts]

Originally Posted by SloPoke

I'm not all too excited about putting Silicone or RTV on the cowling of my Seneca, I know how that stuff makes taking things apart in the future a tough challenge.

Question for Rusty... What do you think about injecting expanding foam insulation ((INSIDE OF A PLASTIC LINER)) into that cavity? It would be molded to fill the contours inside of that, but could be removed when that cowling panel is removed. If there were any extra foam that squished out in an undesired area, it could be trimmed after curing and then put back. Much like delicate electronic systems are shipped in a box.

I probably would work. My experience with expanding foam is it ends up getting on things you dont want it on and can make a mess. Using the foam injected into a bag would be cleaner but I dont think you would get it to flow out into every area, but worth a try. The foam strip I used was super soft and conformed to the contours well. I also though about a thick sheet of foam could be cut to fit and and compressed behind the panel but was worried about it getting water soaked. As far as using a sealant, this is why I used 100% silicone and not RVT as IMO is easier to remove or take apart. There was only a couple small spots it oozed out and just wiped it up. I am not worried about if it has to be taken apart and the actual contact surfaces are minimal and will be thin enough to just pull off. You could also try a thin peel and stick weather striping on the contact surfaces if you didnt want to use silicone.


RVermont, I went ahead and siliconed the bottom up tight as any water can still run towards the inside and down the inner fender panel and any water that gets in behind the cowl panel can still run out the back by the door jam.

[TerrenceB]

Originally Posted by RTVing

So helpful!! Have spent too much time roaming isles. Tried the earplug method but wont stay in and proved to us it did make a difference.

Originally Posted by SFM

Great tips and pictures on everyone’s part. I am picking up our 2019 TS in the morning. I have not seen the unit or driven a newer model. Do you think the folks at Freightliner would have made any changes on the 2019 units??? First stop may very well be Lowe’s for Hillman plugs and silicone.

We purchased a 2019 37K followed the comments by owners in this thread, used electrical tape on all holes and around the top brackets temporarily, took care of the wind noise, purchased the Hillman nylon plugs, 8- 9/16" and 4- 3/4" should do it for the mirror frame mounting holes. I initially covered the odd shaped holes on the mirror brackets themselves and road tested before covering the 2 mirror frames mounting brackets on each door. These made no difference in eliminating the wind noise, so have to conclude its the actual frame mounting brackets to the doors with the plugs described. I also temporarily covered the "swivel" gap where the mirror frame mounts to the mounting brackets on each door. If I plug all the holes and remove the tape from the "swivel", and the noise returns, I may use monkey tape to cover the gaps in that swivel mount. One issue yet unresolved, is the radio antenna on the drivers door and the "hoop" around the base of it. I initially taped the antenna against the door frame and covered the "hoop" with tape along with the other holes covered. No wind noise, I then released the antenna, still no noise, but I haven't driven again with the "hoop" uncovered. This website has been terrific in giving me ideas to resolve this nagging issue. Hope my comments help!

[TerrenceB]

Originally Posted by Bruceter

Well after plugging all of the mirror bracket holes the whistling noise is still there, maybe a slight difference but not much.
Looks like I will have to look into these other areas and sealing them off.

Bruce

I similarly temporarily covered the mirror bracket holes with electrical tape, no difference... I covered ALL the mirror bracket mounting holes to the door, top and bottom and the top swivel gap temporarily with electrical tape, and the whistling noise is gone! I got 10 of the 9/16" and 6 of the 3/4" Hillman black nylon plugs as previously suggested from Lowes which fit but are a little loose, and used a little clear silicon on the sides to help secure them. These plugs have a rounded flared top and make a clean looking installation. I had also used electrical tape temporarily to cover the gap on the top of the bracket that mounts to the door. After I road test these plug installs I will take the tape off the top and see if I can isolate this area as the actual cause of the whistling noise, and if so decide on a clean looking fix.

[dramo77355]

An update from my previous post:

I re-installed the antenna last week, as I had removed it during my efforts to stop the wind noise. I took the Seneca for a drive and found some whistling noise had returned after the antenna was reinstalled. I stopped and took off the antenna and no more whistling. This a 2018.5 Seneca with the telescopic silver am/fm antenna.

[TerrenceB]

Originally Posted by dramo77355

An update from my previous post:

I re-installed the antenna last week, as I had removed it during my efforts to stop the wind noise. I took the Seneca for a drive and found some whistling noise had returned after the antenna was reinstalled. I stopped and took off the antenna and no more whistling. This a 2018.5 Seneca with the telescopic silver am/fm antenna.

Sorry I am new to this forum, don't remember the name of the person that had ordered a new replacement antenna from Amazon, was going to report after he installed and tested, haven't heard yet. Our 2019 37K has probably the same antenna as yours with a "hoop" above the antenna base. After temporarily covering all 16 holes on the mirror frame top and bottom mounting, and the top bracket mount gap with electrical tape, wrapping the antenna "hoop" with tape and taping the antenna against the windshield "post", the I-4 interstate run took care of the whistling wind noise at 45+ mph. I got the 10 of the 9/16" and 6 of the 3/4" Hillman nylon plugs previously suggested and installed them with a little silicon. I released the antenna with no noise difference, but with the hoop still covered. I will road test it tomorrow to confirm that the plugs work, and then remove the tape from the "hoop" to isolate that as a possible culprit. I assume the purpose of the "hoop" is to limit the travel of the antenna, the radio has crappy reception anyway, perhaps another antenna might be the answer.



I understand Jayco previously used a Garmin radio/gps and changed for some reason to our "Soundstream AV Center". It has some nice features, but the display is poor, low resolution / brightness. The touch controls are small, and difficult to use particularly while driving. I would welcome any suggestions to replace it.

[SFM]

Originally Posted by TerrenceB

Sorry I am new to this forum, don't remember the name of the person that had ordered a new replacement antenna from Amazon, was going to report after he installed and tested, haven't heard yet. Our 2019 37K has probably the same antenna as yours with a "hoop" above the antenna base. After temporarily covering all 16 holes on the mirror frame top and bottom mounting, and the top bracket mount gap with electrical tape, wrapping the antenna "hoop" with tape and taping the antenna against the windshield "post", the I-4 interstate run took care of the whistling wind noise at 45+ mph. I got the 10 of the 9/16" and 6 of the 3/4" Hillman nylon plugs previously suggested and installed them with a little silicon. I released the antenna with no noise difference, but with the hoop still covered. I will road test it tomorrow to confirm that the plugs work, and then remove the tape from the "hoop" to isolate that as a possible culprit. I assume the purpose of the "hoop" is to limit the travel of the antenna, the radio has crappy reception anyway, perhaps another antenna might be the answer.



I understand Jayco previously used a Garmin radio/gps and changed for some reason to our "Soundstream AV Center". It has some nice features, but the display is poor, low resolution / brightness. The touch controls are small, and difficult to use particularly while driving. I would welcome any suggestions to replace it.

The report for the antenna from Amazon is mixed. No wind noise but the reception suffers from being so small. I may try a little longer antenna next week. I agree completely with regards to the Soundstream AV System. I have found using the remote works well when driving to control and change of station. To enter an address for the GPS, forget it. Very cumbersome and poor map quality. It took 15 minutes to enter an address. The touch screen is very poor quality and very difficult to enter the letters as it populates itself with random cities or streets. A replacement is on the priority list.

[TerrenceB]

Originally Posted by SFM

The report for the antenna from Amazon is mixed. No wind noise but the reception suffers from being so small. I may try a little longer antenna next week. I agree completely with regards to the Soundstream AV System. I have found using the remote works well when driving to control and change of station. To enter an address for the GPS, forget it. Very cumbersome and poor map quality. It took 15 minutes to enter an address. The touch screen is very poor quality and very difficult to enter the letters as it populates itself with random cities or streets. A replacement is on the priority list.

Appreciate your response on the antenna, sounds like its at least related to the wind noise issue... Our last motorhome had the radio antenna on the roof, too bad Jayco cut corners on the antenna installation. I forgot about the Soundstream AV remote in my previous comments. I agree, the remote makes the radio at least more user friendly. Although the GPS menu offers some useful features, that display is very poor resolution and dim particularly with sun glasses on. I did buy a Garmin RV770 GPS, nice size, very bright which I mount low on the windshield, closer to your line of vision while driving. Garmin has since come out with some newer models with upgraded features. I also would like to replace the Soundstream AV but with something compatible with the backup camera. The side cameras are not a high priority as the mirrors are pretty effective, and I would prefer to continue to see whats behind me when I am turning, or preparing to turn. I will explore options for the Soundstream AV replacement, will let you know, let me know also if you have success with another antenna.


Another comment- we try to avoid the dash air with the loud engine fan, generally run the Onan gen with the A/C's running, worked well in the past with previous "A" motorhomes. Really don't get enough air flow in the cab on really hot days in Florida which seems to be more often today... looking for ideas on installing 1 or 2 small 12 volt fans to move the air into the cab better. Any thoughts? I believe your in Las Vegas, similar experience?

[Tbrek]

I picked up a 2020 Seneca a couple weeks ago...was surprised at how loud the cabin can be, but even more surprised/annoyed by the loud whistling when getting up past 45mph. I suspected the mirror brackets and crudely put some black duct tape over the top bracket attachment and fixed that problem pretty well. I'll check some of the good suggestions above for other cabin noise issues.

[Mnwelsh]

Another source of wind noise is the radio antenna. I replaced mine with a shorter one and it stopped a high pitch whistling.

[thecsfour]

Originally Posted by Mnwelsh

Another source of wind noise is the radio antenna. I replaced mine with a shorter one and it stopped a high pitch whistling.

Where did you get this antenna and does it still get good reception?

[Rustynuts]

Originally Posted by thecsfour

Where did you get this antenna and does it still get good reception?

Just be aware that is you have a 2018.5 with the Garmin/Fusion unit that the factory antenna is also the GPS antenna and some other antennas are not comparable with the GPS. This may affect other other units with built in GPS head units.

[thecsfour]

Originally Posted by Rustynuts

Just be aware that is you have a 2018.5 with the Garmin/Fusion unit that the factory antenna is also the GPS antenna and some other antennas are not comparable with the GPS. This may affect other other units with built in GPS head units.

Ah... Good point.. Thanks! Just looking to try to eliminate more noise. I still have a some whistling going on even after I have done the mirror plugs and the seal as shown on the first part of this post.

[dneeld52]

Originally Posted by Rustynuts

Just be aware that is you have a 2018.5 with the Garmin/Fusion unit that the factory antenna is also the GPS antenna and some other antennas are not comparable with the GPS. This may affect other other units with built in GPS head units.

Rusty,
I have the 2018.5 unit with the Garmin. I bought the unit recently in Ormond Beach, Florida. My unit's antenna is pretty severely corroded, evidently from the salt air. What antenna would I procure to replace my existing? Is this something I buy from a Garmin distributor, or is it a certain kind of antenna that would be available from most retailers?
Thanks in advance.

DamianNeeld
Carmel, In
2018 Seneca HJ

[dcs500]

After curing the noise from covering the holes on the mirror brackets, I still had a whistle. I found that when I lowered the antenna, it went away.

[Rustynuts]

Originally Posted by dneeld52

Rusty,
I have the 2018.5 unit with the Garmin. I bought the unit recently in Ormond Beach, Florida. My unit's antenna is pretty severely corroded, evidently from the salt air. What antenna would I procure to replace my existing? Is this something I buy from a Garmin distributor, or is it a certain kind of antenna that would be available from most retailers?
Thanks in advance.

DamianNeeld
Carmel, In
2018 Seneca HJ

I had the same issue after about a year and I though I had found a replacement, one off a Jeep matched it exactly until I got it in hand and thats when I discovered about the GPS system running through this antenna. What I ended up doing is removing the antenna and base, the antenna itself is stainless and I just polished it back up with some polish. The base was badly rusted and corroded and I ended up sandblasting it (I have a cabinet blaster) and painted it black with a zinc primer and then black paint. If I was going to try and find a replacement I would probably start with checking with Garmin.

[mxracer9111]

Originally Posted by Mnwelsh

Another source of wind noise is the radio antenna. I replaced mine with a shorter one and it stopped a high pitch whistling.

Can you please attach a link or advise a possible part number. My antenna is rusted and needs to be replaced. I want a shorter one for wind noise.