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SL500: Noise from rear interior wall (gas tank?)

272K views 344 replies 119 participants last post by  DecoThom  
#1 ·
I have a 2003 SL500. I hear either a free dangling object behind the seats or perhaps a noise from an object in the gas tank (not sure where the tank is). This clanging noise is heard when car is shook. Even a light nudge of the car will cause it to clank. Like a dangling object, hard accelleration will cause the noise to go away but when the car stops accelerating a clanging noise is heard. The car is running perfectly. This may have started happening while my car was parked overnight seeing as though it would have been hard to miss it when parking the night before. I can not rule out vandalism of some sort but I am having a hard time seeing how this could be the case.

What is located between the rear storage compartments (CD changer) and the trunk?

Is it possible to get objects in the gas tank? I would think there would be a strainer of some sort preventing this.

Striking the rear wall of the interior compartment seems to make a noise consistent with the clanging.

Please help!
 
#2 ·
My wifes car is a 2003 SL500 and she was complaining about a noise coming from where the hardtop is stored when in the open position. I went to the car and shook it from side to side. It sounded like something got loose in the gas tank and was hitting the inside tank walls when the car is moved rocking the fuel in the tank. I took the car to the local Mercedes dealer, upon inspection they said that the baffle inside the gas tank had come loose and was floating on top of the fuel banging inside the tank. They also informed me that the car was 2 months out of warranty and it would take 18.5 hours to remove and replace the tank as all the rear suspension has to come down. The tank itself cost is 1500.00 Canadian dollars. This is hard to swallow for a car that has 36000 KM (22000 miles). This happened yesterday Dec. 30 and there was a skeleton service staff and the service manager was not in to discuss the issue but he has been superb with me in the past having owned numerous Mercedes Benz automobiles. I"m wondering if the fuel tank is covered under the 8 year emissions warranty also.
 
#4 ·
Poor Mercedes workmanship

Thanks for your feedback. I guess that is just as I suspected once I discovered the noise almost goes away on a full tank.

If anyone has a good resolution to this while the car is out of warranty then please let me know. My car is also just out of warranty and I have owned it for only a couple of months. I feel a lawsuit/recall coming on. It does not seem to safe to me to have a shard of metal drifting around in my gas tank. Definately poor Mercedes workmanship. It appears this will be my first and last Mercedes unless something positive happens. They are not off to a very good start since I have call two dealerships and they have both denied having knowledge of the problem. This is likely a lie. I will call several other independent Mercedes mechanics to confirm this.

It kind of makes you wonder how Mercedes could be upset by their quality rating this past year. This has easily been the most unreliable car I have ever owned.

Just finished a 900 mile road trip while listening to the clanging. I also had a momentary coolant warning while at the tail end of the trip. The temp appeared to become a bit unstable for a moment. It appeared the temp may have gone about one to to notches above normal for about twenty seconds. I suspect the themostat may have stuck. I may need to unload this car before anything else happens.

This is particularly souring since my previous car was a Mitsubishi Eclipse priced at a quarter as much and the only repair I needed to make to it was a replacement of the driver-side windsheild wiper spray nozzle.

Along with prestige there is integrity. I am yet to see any integrity in the Mercedes corp.

Thanks,
Jim
 
#168 ·
I paid $ 2353.00 to replace my tank because of a baffle that came loose within the tank. I have a 2004 SL55 AMG. Sorry to be the bearer of bad news. Good luck. Mercedes is well aware of the problem but I had to pay.
Thanks for your feedback. I guess that is just as I suspected once I discovered the noise almost goes away on a full tank.

If anyone has a good resolution to this while the car is out of warranty then please let me know. My car is also just out of warranty and I have owned it for only a couple of months. I feel a lawsuit/recall coming on. It does not seem to safe to me to have a shard of metal drifting around in my gas tank. Definately poor Mercedes workmanship. It appears this will be my first and last Mercedes unless something positive happens. They are not off to a very good start since I have call two dealerships and they have both denied having knowledge of the problem. This is likely a lie. I will call several other independent Mercedes mechanics to confirm this.

It kind of makes you wonder how Mercedes could be upset by their quality rating this past year. This has easily been the most unreliable car I have ever owned.

Just finished a 900 mile road trip while listening to the clanging. I also had a momentary coolant warning while at the tail end of the trip. The temp appeared to become a bit unstable for a moment. It appeared the temp may have gone about one to to notches above normal for about twenty seconds. I suspect the themostat may have stuck. I may need to unload this car before anything else happens.

This is particularly souring since my previous car was a Mitsubishi Eclipse priced at a quarter as much and the only repair I needed to make to it was a replacement of the driver-side windsheild wiper spray nozzle.

Along with prestige there is integrity. I am yet to see any integrity in the Mercedes corp.

Thanks,
Jim
 
#5 ·
lvfjmbusa said:
We replace those tanks all the time. that is the noise for sure

I appreciate your candidness. I just realized you appear to be a dealership out of Las Vegas. If only the FJ here would be as helpful.

Are you authorized to make this repair with the car out of warranty? This seems to be a recall item. What do you charge for replacement? Can you tell me the actual time required to make the repair? Are you aware of a safety risk associated with this problem?

What do you mean by "all the time"? Have these tanks been upgraded since the 2003 model sl500?

Thanks again!!

Jim
 
#6 ·
Rick Cell said:
My wifes car is a 2003 SL500 and she was complaining about a noise coming from where the hardtop is stored when in the open position. I went to the car and shook it from side to side. It sounded like something got loose in the gas tank and was hitting the inside tank walls when the car is moved rocking the fuel in the tank. I took the car to the local Mercedes dealer, upon inspection they said that the baffle inside the gas tank had come loose and was floating on top of the fuel banging inside the tank. They also informed me that the car was 2 months out of warranty and it would take 18.5 hours to remove and replace the tank as all the rear suspension has to come down. The tank itself cost is 1500.00 Canadian dollars. This is hard to swallow for a car that has 36000 KM (22000 miles). This happened yesterday Dec. 30 and there was a skeleton service staff and the service manager was not in to discuss the issue but he has been superb with me in the past having owned numerous Mercedes Benz automobiles. I"m wondering if the fuel tank is covered under the 8 year emissions warranty also.

How is it your car is out of warranty with only 22000 miles?
 
#9 ·
mercedes sl500 review defects

My car is currently at the dealership. I am not sure how this is going to go. They have had it all day and are insisting I take a loaner car while they deal with corporate.

A portion of my argument is that this is most likely a fatigue type failure of the gas tank baffles or something used to fasten the equipment inside the gas tank. This was no doubt already a problem before the warranty ran out.

It still seems to me that the sound is caused by something hanging in the tank. However, I do not know what a floating baffle would sound like. It is difficult to explain but it seems to me that gravity is keeping the object in the tank in contact with the front side of the tank. I say this because striking the tank causes a bit of rattle noise. Perhaps the baffle piece is so large that it is always in contact with the side or another baffle.

Note that the noise will almost go away when the tank is full and as I dropped the car off at just over a quarter of a tank, it again seems to be more quiet. Seems to be loudest at about a half tank.
 
#10 ·
They have been working on mine since Tuesday and said it should be ready on Monday. They are probably waiting for the corporate boys to return to work on Monday so they can figure out how to deal with this situation. I hope I don"t end up with a battle as I already told them that they should be responsible for the parts and labour.
 
#11 ·
sl500 defect

Similar situation on my end. They have finally gotten authorization to inspect the tank. Sounds like these guys need to invest in an optical scope to diagnose these without tank removal. I was surprised to read that they were able to diagnose yours so quickly. Seems as though your dealership is quite familiar with this problem.

Anyway, so far Mercedes is handling this quite professionally. I have a loaner car and as of yet I have not been billed anything. I would not expect them to say "Oh yeah, are gas tanks have problems and we will fix it for you". I do expect them to repair it upon being given the reason and proof that the cause of problem is an Engineering goof we would hope is not typical in $100000 car. Also, the same proof would likely suggest that our vehicles were defective long before the warranty ran out. I would imagine it would take a long time for a baffle to break free. I will reserve judgement for later. Good Luck Rick. If I confirm that my problem is indeed the baffle, we should probably share our info with each others service manager. There is power in numbers.

I think the demographics of the typical Mercedes owner is hurting the paticipation in this forum. Calls around to independent Mercedes mechanics and other dealers suggests this problem is bigger than the web may show at this point. Hopefully this forum will catch some steam. Please register and chime in if you have experienced this problem.

I will have to have my German friends do some reseach for me. Perhaps the information we are looking for is not in English.

By the way, if you do a Google search on "sl500 gas tank", this link will be the #1 hit!


Does anyone know what material the SL500 gas tank is made of?
 
#12 ·
The service manager called me last night on my way home from the office and said that the car is ready to be picked up. He said that they are willing to help cover some of the repair but I would have to cover some also. I told him I did not need the car back right away but to work the numbers and call me on Monday with the total. He is a great guy but I hate going into my pocket for anything regarding this gas tank issue as I feel they should be on the hook for it all. My wife is not complaining about not having her car as she is driving my super charged Range Rover sport .
 
#16 ·
I just got my car back. Let's just say Mercedes handled it to my satisfaction. It always helps to be informed before you go in. Telling them what is wrong with your car is better than the other way around.

Thanks goes out to Rick and to this forum. Hope this forum helps out many others as the warrantees expire on the 2003.
 
#17 ·
Taking mine in for the same thing

After digging around in the trunk, opening the convertible in stages looking for a dangling cable with something on the end, and finding no visible source for what sounds to be the same knock, I'm taking my 2003 SL in for the same thing.

Mine is still under warranty, will let you all know what the result is.
 
#18 ·
i'm just the opposite. mine seems to be loudest when it's full.

side1out said:
My car is currently at the dealership. I am not sure how this is going to go. They have had it all day and are insisting I take a loaner car while they deal with corporate.

A portion of my argument is that this is most likely a fatigue type failure of the gas tank baffles or something used to fasten the equipment inside the gas tank. This was no doubt already a problem before the warranty ran out.

It still seems to me that the sound is caused by something hanging in the tank. However, I do not know what a floating baffle would sound like. It is difficult to explain but it seems to me that gravity is keeping the object in the tank in contact with the front side of the tank. I say this because striking the tank causes a bit of rattle noise. Perhaps the baffle piece is so large that it is always in contact with the side or another baffle.

Note that the noise will almost go away when the tank is full and as I dropped the car off at just over a quarter of a tank, it again seems to be more quiet. Seems to be loudest at about a half tank.
 
#19 ·
SL gas tank

Confirmed. Broken baffle in the tank. My dealer first cited it would take 10 days to order from Germany. Two days later got a call car was ready that they actually were able to get one locally (either had it or from another dealer).

Also took care of a myriad of other minor things (factory warranty) and I had brakes put on the car. Total time out of the car, less than 72 hours all in.

Painless, car runs great, and that most irritating knocking is gone! Total cost to me? Only the brakes, everything else under warranty including the tank, no questions asked.
 
#20 ·
03 sl55 44k miles with same tank noise

Does anyone know if MB will cover the tank swap if the car is out of warrantee? Who cares what the in service date is. There is no friggin way a car with 44K that cost 130K should need a new fuel tank! If a Hyundai has a 100K warrantee and I end up spending big money to fix this (after I just goy over the high of paying it off) I'm not going to be too happy.

Anything you guys know will be helpful.

Thanks
Joe
 
#21 ·
My car was out of original warranty. I purchased it used with an extended warranty. The gas tank was replaced without any cost to me. Its a known problem... must be very expensive for them as it took over 7 hours of labor I'm told. I am very please with the service in the end of San Diego Mercedes Benz Dealership (United Auto Group).
 
#22 ·
Mercedes took care of mine but it was just days out of warranty. I did not have to try too hard. Since you can go in there knowing what is wrong and that there is history of a problem then you may be OK.

Typically failures such as these occur over a long period. You could easily argue that the tank has been defective since it was last under warranty but there is no way to know. I suspect an inspection of the tank will show evidence of this. Although I have never seen the actual broken baffle, I suspect it will show a break similar to that of repeatedly bending metal till it breaks. This is a bit of a guess though. In either case, I think you will be OK.

Yes, it is a very large repair and will take several hours.

If they charge you for the repair. Be sure to ask to see the damage and take lots of pictures and post them here.

Good luck!
 
#24 ·
Fatigue failure is common to metal and plastic. I am just speculating that this could be a possiblity. It definately makes a case for free replacement. I hope not or this would imply that all cars may be affected eventually. I continue to monitor this post since I am curious of the details of the flaw. I actually have no idea what the tank design even is. As long as Mercedes keeps taking care of their customers then I suspect this may take awhile to get revealed. However, I'm sure there must be some independent mechanics out there that have some knowlege on this.
 
#25 ·
side1out said:
Fatigue failure is common to metal and plastic. I am just speculating that this could be a possiblity. It definately makes a case for free replacement. I hope not or this would imply that all cars may be affected eventually. I continue to monitor this post since I am curious of the details of the flaw. I actually have no idea what the tank design even is. As long as Mercedes keeps taking care of their customers then I suspect this may take awhile to get revealed. However, I'm sure there must be some independent mechanics out there that have some knowlege on this.
FYI, here is a quote from a MB Mechanic from the AMG Private Lounge.
"Yes, You needed a new Gas Tank. The baffles inside the tank broke and are moving around inside causing that noise. We've been seeing this issue a lot lately on R230 SL's. Not sure what's causing it, or any more specific details about it. I'd say we've probably replaced about 10 gas tanks in SL's in the past month."
 
#26 ·
i have 2003 sl500 . it is out of warranty. today. I discover the noise from the gas tank
as you guy describled. the car has 49000 miles. is there any chance that I can talk to dealer to get the cover for replace the gas tank?. anyone could point me to the direction how to get start ? thanks you for all advice