Just a thought ... The cabin filter is over there. I would check to see if that is wet.

 

Thank you so much for replying so quickly I really do appreciate it. I'll check this out.
many thanks,
Duncan

 

The pano-roof drains are often a problem. They can get clogged with debris and back up into the cabin.
btw: I would never run roof gutter downspouts inside the walls of my home but it's acceptable in vehicles presumably for aesthetics.

Hi, I have a 2016 Gla 220 4 Amatic AMG line with some 18700 miles on the clock bought new. Last week I noticed a pool of water in the near side passenger footwell. Given it had sat in my driveway during two weeks of, at times, torrential rainfall, I'm satisfied the source of water ingress is above, not below the car. The door and sunlight seals are completely sound.
My local garage checked it and suggested the source of water ingress is from the roof runners via internal bodywork, but will cost a lot with a body shop to find and fix.
The twin roof runners are suspected as the only possible source of water ingress, therefore I'm tempted to seal both sides of each runner with a waterproof silicone.
Has anyone else had this problem, if so, what was your solution please?
Many thanks,
Duncan

 

The pano-roof drains are often a problem. They can get clogged with debris and back up into the cabin.
btw: I would never run roof gutter downspouts inside the walls of my home but it's acceptable in vehicles presumably for aesthetics.

Thank you for those replies. I should have said my car it to UK spec, there is no drain pipe or cabin filter fitted. The runners on the sunroof are clear. It looks like I'll need to go to a body shop.

 

Each model year and model type can have somewhat different attributes, so your salesperson is wordsmithing-correct, but the things we're discussing are pretty much a constant.
The pano-roof drain tubes are inside the pillars so you wouldn't see them. Even difficult to see the roof channel drain holes.
I've never had a modern vehicle without a cabin air filter, but possibly they "value engineered" the 2016 GLA 220 to such a degree? Nah, it's still a Benz and they wouldn't do that. "The best or nothing."

 

The roof drains are very well hidden, in the front corners is where you can find them. The only thing you can see is the catch area but do not see the hole for the tubes that go down the pillars.

The cabin filter see this post: Resolved - 2019 GLA45 AMG cabin fresh air intake location

 

A fairly standard way to clean the drains is with weed whacker nylon string. But you do need to use extreme caution to not push the drain hose apart.

 

Indeed, easy does it and don't have the line actually attached to the weed whacker.

I use the stronger "commercial" type of string for this drain line cleaning, as well of course actual weed-whackin'. The video I already linked above goes into more detail.

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A quick update on this. My local garage (who is excellent) did an absolutely thorough check on my car to try and find where water is entering the cabin.
The results were they were able to completely eliminated the sun roof, front and rear drain pipes, doors, bonnet and roof runners as potential source of water ingress.
The conclusion therefore is rain water can only possibly be allowed to enter the cabin from the rear of the car, either through the boot or rear lights via internal air pressure relief vent boxes located behind the rear bumpers.
A MB diagnostic repair will require removal of all seats and carpeting over three days to find and fix the problem.
I've been told this is a frequent fault MB is aware of but have done nothing to fix, indeed it may of always been there from new, but since my car was garaged, would not if been obvious until out of warranty.
If it transpires this is the case, I simply can't believe MB have been allowed to continue such a poor design fault for years without any UK regulatory redress or self imposed recalls.

 

By any chance has a trailer hitch been installed?

 

No.
MB should design and build cars to the required National legislative production and operational standards, (which includes what we in the UK say towing, or as you define, trailer hitching), simply, no car should allow water to enter the passenger cabin and / or any where near car electrics.

 

I agree with everything you say about build specs. But I'm left wondering. Our 45 is left outside and has seen some heavy rain and wind, both when sitting and being driven. But we've never seen water ingress. And to think the moisture entered at the back but only got one side in the front wet makes we question the pathway.

Good luck and please report back as things progress.

 

I agree with everything you say about build specs. But I'm left wondering. Our 45 is left outside and has seen some heavy rain and wind, both when sitting and being driven. But we've never seen water ingress. And to think the moisture entered at the back but only got one side in the front wet makes we question the pathway.

Good luck and please report back as things progress.

Thank you so much for your reply. Water will always go to the lowest gravity point, which in my case is the rear passenger well due to parking in a front to rear right to left incline.
I'm told the problem is 1 in 1000. Maybe youve been lucky, I've not been.
Notwithstanding the water pathway from the rear now appears to be conclusive as absolutely everything else has been checked and excluded. My car underwent an extremely close test and examination procedure by a garage I have known and completely trust over some 40 years. They carefully tested both sides of the car and came to the conclusion water is clearly entering from the rear left hand side. They intimated similar experience with other MB cars of all makes, possibly via the rear lights to an air equalisation vent behind the rear bumpers not being sealed properly against water ingress at production stage which has providec a path for water to gather at a low point.

 

Sorry ... I thought the water problem was at the front seat. It sounds like you have a handle on things. It also sounds like a number of things have to go wrong together to have this problem. Can you fix it by repairing a single point, like sealing the taillights? Good luck as you move forward.