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I’ve heard that all of the GL’s leak from the rear left tail light? During our forced vacation I left her sit for about 1.5 years. Couldn’t use garage because I had to bring some product home ditching our warehouse. When I opened it up I had white mold EVERYWHERE!!! Started cleaning everything with a commercial cleaner I had, and then read oiled everything including the plastics to make sure they were hydrated. I also purchased and ionize machine! Awesome! Just be careful because it will make plastic brittle over time.
I still have a flipping leak I believe. If anyone can offer suggestions please, but here’s my journey and discoveries!
I tore it apart like I left it in the hood with a $100 taped to the dash. I removed a lot more but got tired of taking pictures. Took me about a week to disassemble, clean, use the ionizer, oil and rejuvenate everything, and then reassemble.
I noticed things had stopped working right, so I went on the hunt for that as well. One of the first things I looked at was the hydraulic rear lift stopped. That’s what really lead me down this rabbit hole, outside of just cleaning. Finally found it under the false floor under the spare tire. There had been standing water in it at some point recently. It was parked so the nose was elevated in the drive way. Hell wasn’t worried about the virus, but I was worried about that! Lol… It’s gross. Makes me feel like I’m a pig even though it had been that way for a long time by the looks of it. I found crayons from the previous owner and a ton of other things that fell down.
Every single GL450 apparently has this issue at some point or another. They all corrode since it leaks and it soaks up the water. There’s a WIERD space age foam that they incased the pump in. So the hydraulic pump just marinates in water. I had rang it out MULTIPLE times and it still wasn’t empty. It took about a week to fully dry. I’ve never seen anything like it.
The brilliant engineers mounted the pump and the control unit to the floor instead of a side wall. It’s huge! They aren’t lacking the space to mount it. You could likely hide a body under there! That would have saved a lot of money and headache for people. I just ordered the motor, and not the entire assembly. I can here it clicking and wanting to work, but when you see the pictures the motor is toast.
First picture the support beam on the left side has corrosion, so I’m guessing that’s’ the incoming trail.
I find water every now and again. Anyone have this problem and find the point of entry? All seals around the doors and windows are good.
This spring/summer I’ll just have to disassemble everything and just do the garden hose trick. I ran it though a car wash so after, but couldn’t find anything. I figured the forced air dry would have pushed water into what ever area was leaking. That last photo I had cleaned 1/2 and wanted to show the difference!
When I install the new motor I’m either raising it up, or just mounting it to a wall if the cables will let me. I would suggest everyone look at theirs, and move it before you have trouble. According to everything I’ve read, they all leak.
The source of these leaks are either around the edges of the third row sunroof or the taillight seals.
If you take out the first aid kit holder and on the other side the door, you can isolate the water entry point to either high up on the roof or around the tail light seals by hosing around the twilights, and observing. If still dry, then it gets in higher up - the sunroof weatherstripping.
Not all of them leak, btw. Im 2 for 3 on dry x164s.
the one I had that did leak had a poorly performed replacement sunroof installed by the dealer when the car was nearly new. I could see water dripping down onto the subwoofer in the rain.
Last edited by Max Blast; Feb 21, 2022 at 01:03 AM.
I found a motor for $60. The unit is working, just the motor is destroyed. I hear clicking so I know the computer is responding. For $60 I’ll roll the dice to be lazy! Lol
I have found another source of leak at rear is from the third row opening windows. on a new to me 2008 I found light corrosion l. Stripped the lining out and got my wife to hose from outside with everything closed. Definitely seemed to come in back window. Seemed better if I held the close button for an extended time.
Unsure if This will be ongoing
i undid the rear SAM and made a little support so it hangs from the black floor support (to keep it dry). I don’t think I did a photo.
I have the Subwoofer above the SAM so little space there
I have found another source of leak at rear is from the third row opening windows. on a new to me 2008 I found light corrosion l. Stripped the lining out and got my wife to hose from outside with everything closed. Definitely seemed to come in back window. Seemed better if I held the close button for an extended time.
Unsure if This will be ongoing
i undid the rear SAM and made a little support so it hangs from the black floor support (to keep it dry). I don’t think I did a photo.
I have the Subwoofer above the SAM so little space there
There are little knockout rubber plugs. Take a small drill bit, an x-acto knife, anything, cut a weep hole in the plug. Kinda criminal MB didn't think to do that. It won't certainly save the SAM but should help.
The source of these leaks are either around the edges of the third row sunroof or the taillight seals.
If you take out the first aid kit holder and on the other side the door, you can isolate the water entry point to either high up on the roof or around the tail light seals by hosing around the twilights, and observing. If still dry, then it gets in higher up - the sunroof weatherstripping.
Not all of them leak, btw. Im 2 for 3 on dry x164s.
the one I had that did leak had a poorly performed replacement sunroof installed by the dealer when the car was nearly new. I could see water dripping down onto the subwoofer in the rain.
Leaving the vehicle outdoors both dries and cracks the seals - including the rear popout windows - and subjects the vehicle to moisture.
I wanted to pull the rear SAM and take a look because I’m having little hiccups. It’s perfect. I’m guessing that they had problems before, because there’s a foam cover that directs water away. Kinda like the baffles you in close speakers in your door to protect them. I happen to have parked outside 2 days ago and it rained pretty good. Boom… It’s raining from the passenger side, but it strange. The walls all see dry, but the top of the subwoofer has water on the casing. Once you remove the rear plate to pull up that truck cover that felt is wet….
Anyone had that issue? I don’t think it’s coming from the plastic room, but lord who knows. I’m gonna start pulling panels apart tomorrow now that I found the water!
GOOD NEWS the SAM looks perfect. I removed everything electronic, and disassembled the SAM and cleaned everything really well. I lost a small cable and can’t connect the SAM back! lol…. It dropped in temp quick here so calling it a night since I have to have the garage door open. The horn stopped working, the Parkmatic, heated seats and maybe 1 other thing. I had read that it was possible the rear SAM. I cleaned ever electric component in the rear since there had been water. Next I’m moving to the bat cave, sorry battery cave. I think there had been water there too. Anyone have a direct source for that box leaking?
I’m glad Mercedes doesn’t manufacture boats! My god… I’ve never seen a car leak like this, and the comments I’ve read.
Went I thought I couldn’t hate Mercedes and their alcoholic, drug using engineers any more… Here’s how you too can become alcohol and drug dependent, while getting to the route of your water leak. Have fun! This is going to be a long as weekend. I’m buying the panoramic roof seal in advance, and changing it regardless. I’ll try and document as much as possible…
Yep. She was always garaged with previous owner, and we always had it garaged until our forced vacations. I had to move product from my company into my garage and couldn’t put it inside. That’s when all of the funkiness started. But yep all of my seals are looking dry rotted regardless.
It is kind of sad that a Gelandewagen needs to be kept out of the sun and rain, but it is what it is.
I am in dry Idaho, so precipitation just is not that much of an issue, but next time I pull the battery, and poke around the passenger rear well where the SAM is, I am going to open up weep holes in those wells.
I started pulling it apart last night. I’m dragging EVERYTHING out. Even got that subwoofer out… I’m just going to redo everything while it’s open. Then I don’t have to do this crap again. Got all of the seals on the way. Think I’m going to do the flex coat or some spray, and when I put the bolts for the roof rack pillars back in I’m going to seal them up properly, putting a sealant on the thread, or anywhere else I can. I just can’t believe this bs happens to even the new models and no one has sued Mercedes yet for negligence.
They know it’s happening and even admitted it in their design!!!! The rear SAM is covered in that foam baffle like you wrap your speaker in inside the door. I mean that 100% admits that they expect the damn thing to leak! Doors you can’t seal, so that’s expected to get water inside. But the interior?????
Hello there, buddy. I completely get what you're saying. I rent a limo, and when it returns to the garage, it is always full of leaves, water, and filth. I went to Crown Cleaners the first time, but after the fourth occurrence, I couldn't stand it any longer and stopped renting out my limo. Unfortunately, the problem was not resolved after that. It wasn't until later that I learned the issue was a malfunctioning sunroof and gaps in the headlights. It's possible that you're having the same issue. I strongly advise you to pay attention to this and double-check them just in case.
Last edited by PeterFisher0; Apr 13, 2022 at 06:11 PM.
I’ll post a complete run down later, but it’s been a “fun” ride… 🤦♂️ There are multiple entry points possible, found the current and possible future, and waterproofed the sh.. out of them! Now it’s as watertight as a ducks butt. Stupid crap Mercedes should have done!!!!!
Also I applied sound deadener everywhere, including the back of the headliners. Now it’s rubber, and god forbid any new leaks it won’t destroy that again! I’m having the headliner and pillars re-upholstered while they’re out.
Oh yeah… that rear panoramic window, good luck. It’s not a seal or gasket. It’s put in with the exact same glue they put your front windshield with, and has to be chipped out from inside the cab!!!! There went $600… just to remove it and reseal it.
Last edited by Scott Hart; Apr 10, 2022 at 10:29 AM.
Great write up, thanks for taking the time to do so!
I’ve had a similar issue; small leak resulting in wet padding in the area underneath the Rear right Sam, and the rear left first aid kit area.
left was worse than right, and neither was leaking enough to interfere with anything.
I had been using left over baby diapers to absorb the water and replacing as required.
recently sealed the two rubber bungs that are left and right on upper frame of the body in the opening for the lift gate, under the plastic trim. They were old and slightly worn, appeared too loose, and a lot of debris was built up.
hope that solves it; I’d hate to have to strip everything out like you’ve done.
look forward to seeing the end result of your project!
So to answer the question… no I have not finished.
Can’t upload video here so here’s 2 screen captures. 1st is before I got headliner down. It was literally like a waterfall… All 4 sunroof drains were sudo clogged, but funny because damn thing has spent a good majority of time garaged since new.
NOW… Let’s talk about the 2nd photo… 😡 That’s the front corner of that horrible plastic roof window. It is leaking like I thought since the begging. Best part I found the seal! There isn’t one. 🤣 It’s attached just like your front windshield is. They have to get inside the car and chisel it out… praying to god they don’t break it. Somehow I’ll still be responsible because it’s not a traditional window removal.
Trying to figure out if I can just black heavy duty silicone it from the top or bottom/inside… I Wanna do it right, minus spending another $600 to just remove and reset it. Just had all of the fabric redone so I don’t want to have this issue again.
If I caulk around top it’ll get old and brittle, and eventually fail. If I caulk underneath there’s no guarantee I’ll get it, or water will still get inside the external crack and then work it’s way somewhere else…
If you DO suspect you have a water leak disconnect the rear hydraulic lift pump asap! I though I had it 100% disconnected, but plugged it back in for something… Few days later had stopped the car to run inside a store but smelled something electrical burning. Hunted around and couldn’t find anything. And I searched! Have the nose of a bloodhound and still couldn’t find it.
Figured I really triple search before I went home. Came back out got in the car and thought crap… so when I opened the rear hatch the computer to that pump had JUST caught on fire! Legit maybe 1/4” flame on the wire where it connected. Heck 30 seconds more and I wouldn’t have had to post here anymore! 🤣
PSA; Take a look at your hydraulic pump under the spare tire. If yours is corroded disconnect it entirely.
2. It takes getting on a ladder to inspect sunroof seals on these … they are tall vehicles. Can’t say I’ve ever inspected mine in (also) 15 years.
3. I suspect maybe there was a Ford Expedition and for sure there were GM Suburbans 15 years ago. Somewhat comparable vehicles, I think. Wonder how they’ve aged in comparison to GLs?
2. It takes getting on a ladder to inspect sunroof seals on these … they are tall vehicles. Can’t say I’ve ever inspected mine in (also) 15 years.
3. I suspect maybe there was a Ford Expedition and for sure there were GM Suburbans 15 years ago. Somewhat comparable vehicles, I think. Wonder how they’ve aged in comparison to GLs?
if you’re reasonably fleet footed you can stand on the rear tire and look at the third row sunroof seals.
Comparably a GM suburban from 2006-7 doesn’t have this largely unnecessary third row sunroof, but a whole host of problems on its own and nowhere near the ride quality and quietness of a similar GL. I actually had a 2005 suburban and another 07 GL at the same time and you couldn’t really compare the ride at all. One is a half ton pick up truck/ox cart, and the other one is a smooth riding air suspended couch on wheels.
That being said, the burbs much simpler and parts are plentiful and cheap, so it will literally go forever. You will replace transmissions every 5 to 7 years or 150 K miles. You will not find one that doesn’t have the driver seat outside bolster cracked ripped or cratered. The steering shaft wears out with amazing regularity. Other than that it’ll do whatever the hell you ask of it. Everything you don’t really need will always be broken, and everything you do need will always work.
As for the Fords, the expedition with the V 10 I think it’s pretty bombproof except for when changing plugs… stuck plugs extricating labor bill is what totals these things. If you’re uninformed enough to get one with a 4.8 V8 expect to change motors every hundred thousand or so they are a flawed and cursed design.
For both of the above the interiors just collapse and smolder away after about 10 years so hard whereas the GL’s is still in one piece, save for the sticky goop on the steering wheel control buttons.
But my GL soldiers on with a minimum of care, because I did my homework when I bought one that was completely dry inside.
Last edited by Max Blast; Jul 17, 2022 at 12:09 AM.
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