Help! - brand new sprinter leaking water into interior

seetrai

2021 170 4x4 v6 (SF Bay Area)
Hi,

Just picked up my 2021 170 Cargo 4x4 last week and removed the factory interior panels. it started raining like crazy and now I have a little trickle "starting" from inside the wall directly behind the sliding door then flows out of a little hole in front of the wheel well resulting in a little pool in the back of the cargo. The van is on a slight 5 degree hill. I'm not sure where it is originating, but the first place I see it is shown in the pics (about mid way up the wall which looks like one of the bolts for the sliding track.

Any ideas, thoughts or similar experiences?

Thank you in advance
 

Attachments

mkeys

Asking the dumb questions so you don't have to
Being brand new I am sure talking to the dealership is the right way forward here. As far as where this is coming from, my first thought is one of the roof rail mounting points as those penetrate through the roof. If you don't have roof rails you would have a little plugs at each mounting point instead.
 

hilld

Well-known member
Yes, most likely where the sliding door track is on the outside of the van as you have already diagnosed. Not sure how responsive your dealer is, but perhaps it might be easier to loosen the track and get a gap and add some sealant behind the track. Most likely the culprit.
 

seetrai

2021 170 4x4 v6 (SF Bay Area)
It could definitely be either of those (roof rail which I have or the slider track). I also noticed that the water coming out of the wall is NOT out of the OEM hole, but out of the weld? at the bottom. Guess I'll need to take it to the dealer who'll likely tell me it is 2+ week wait for an appt. I'm grateful this happened now and not after months of conversion.

Thank you
 

Poncho67

Member
Yep. Most likely leaking from the sliding door mount holes. If you can get a small mirror and a bright flashlight in there you may be able to find the source. Dealer will fix it but like you said it will be awhile. The soonest I can get my 2021 in for a fix regarding a malfunctioning seat belt/ airbag warning was 3 months out.
 

bordeaux

Active member
Have seen this before and it was entering behind the sliding door top rail and coming down the inside of the C pillar before showing it's self running down the panel. With the sliding door open try tipping some water on to the rail at the end nearest the C pillar.
 

Attachments

seetrai

2021 170 4x4 v6 (SF Bay Area)
So I dripped some water on the roof rail so it would flow down the c pillar. Yup, started leaking. Then found if I only poured on the little protrusion about a foot above the slide rail, it leaked. Took it to the dealership (where they won't even be able to look at until later in the week, ha).

Thanks all for the help! Just in time for the next heavy rain we are having.
 

seetrai

2021 170 4x4 v6 (SF Bay Area)
I thought about just doing it myself, but being that it is a week old, figured I'd just get it checked out.
 

hakkattakk

2019 144WB High Roof 4x4 Cargo/Crew
FYI I had water leaking (pouring) through the OEM roof rail mounting bolt holes during the same storm. I had to remove L-track, plywood ceiling and wall panels and peel back my insulation to find the source.

With a neighbor's help, I tightened the bolts while testing with a garden hose which stopped the leaking, as there are rubber grommets under the rails to seal the bolt holes. I went back after drying everything out and secured the nuts with Loctite. Thankfully, I used Thinsulate insulation under the panels which dried out fine, so there's no mold, but the wall panels do show some water damage, which I'll paint or finish later.

I have a FLVCO Low Pro roof rack mounted, and had a 10 gallon road shower water tank on the roof all summer, which may have contributed to loosening, and almost all of these OEM roof rail bolts were finger loose. I think MB should've used nylock nuts or some Loctite.
 

seetrai

2021 170 4x4 v6 (SF Bay Area)
FYI I had water leaking (pouring) through the OEM roof rail mounting bolt holes during the same storm. I had to remove L-track, plywood ceiling and wall panels and peel back my insulation to find the source.

With a neighbor's help, I tightened the bolts while testing with a garden hose which stopped the leaking, as there are rubber grommets under the rails to seal the bolt holes. I went back after drying everything out and secured the nuts with Loctite. Thankfully, I used Thinsulate insulation under the panels which dried out fine, so there's no mold, but the wall panels do show some water damage, which I'll paint or finish later.

I have a FLVCO Low Pro roof rack mounted, and had a 10 gallon road shower water tank on the roof all summer, which may have contributed to loosening, and almost all of these OEM roof rail bolts were finger loose. I think MB should've used nylock nuts or some Loctite.
Thank you, I'll check each bolt while I still have the ceiling open
 

seetrai

2021 170 4x4 v6 (SF Bay Area)
So my van spent a week at the dealership, and they said they fixed it. Got it home and tested myself... nope, same leak. So I isolated the leak and temporarily duct taped it which seemed to work. but the next storm there was still a small leak. So she'll be heading back to the dealership at some point. ugh.

I may just put some clear silicone to see if that holds better than the duct tape, or maybe there are multiple leaks that present themselves in the same area.
 

Happy29

2020 2500 OM642 4x2 170HR
Not sure I'd trust a dealer to fix that. You'll likely do a better and more complete job than a tech trying to wade through numerous vans with various issues. Seems like a big waste of your time for it to sit for a week and not be corrected. Why the F are these being built to such a low standard! Oh yeah, South Carolina.
 

Sprinter SS

Well-known member
do not use silicone based sealers on sheet metal. They have a high concentration of acedic acid which is corrosive long term to steel and aluminum. Preferable sealant would be a polyurethane base sealer that is cut with a solvent (mineral spirits or lacquer thinner). The exterior seams on the factory seams are by Sikaflex, polyurethane.

You can even by the polyurethane based sealers at big box stores, check for the OSI Quad product.
 

seetrai

2021 170 4x4 v6 (SF Bay Area)
do not use silicone based sealers on sheet metal. They have a high concentration of acedic acid which is corrosive long term to steel and aluminum. Preferable sealant would be a polyurethane base sealer that is cut with a solvent (mineral spirits or lacquer thinner). The exterior seams on the factory seams are by Sikaflex, polyurethane.

You can even by the polyurethane based sealers at big box stores, check for the OSI Quad product.
Uh, didn't know that. Thank you for the heads up!!
 

Top Bottom