Mercedes 500 sec rattle from fuel tank........... advice needed

[sarb1984]

Firstly an update of how the SEC is looking now after a good detail and front and rear windscreen replacement.

I have an issue currently where each time I drove the car I could hear a very odd rattle from inside the boot, I always thought it was maybe a wire hitting against the body of the car or then the rear speaker shelf. I have now stripped the car down 2/3 times and after finally having enough of this rather annoying noise I managed to pin point it down to being from the fuel tank. I have now got the rear seats all out as well as the parcel/speaker shelves and have also removed the metal divider in the boot which sits just in front of the fuel tank as well as all the boot carpets. Each time I hit the top of the fuel tank near the petrol filler side there is a rattle inside the fuel tank which in fact continues for a couple of seconds after too. It seems likes it towards the top right hand side of the fuel tank, I read somewhere it may be the baffles inside but obviously I have no idea what any of that means.

Rather then going to a specialist to have the entire tank taken out for 'investigations' followed by a huge invoice is there anyone that has had a similar problem or if someone knows what can be done without taking the entire tank out, all help will be greatly appreciated!

 

[merc85]

Probably a broken baffle id assume, Replacement tank being the most easiest of options if you can find one.

What a stunning vehicle btw

 

[sarb1984]

Probably a broken baffle id assume, Replacement tank being the most easiest of options if you can find one.

What a stunning vehicle btw

Are broken baffles not repairable? Im sure a new tank plus fitting can't be cheap.

 

[merc85]

The tank would have tobe cut open, baffle welded then weld the tank water tighten and refitted.

 

[optimusprime]

This might be silly, but are the tools in the tooll roll secure and also the jack ? Serb 1984 you have my next car there ..very nice i must say . Hope you find an easy fix .

 

[sarb1984]

This might be silly, but are the tools in the tooll roll secure and also the jack ? Serb 1984 you have my next car there ..very nice i must say . Hope you find an easy fix .

Oh I’ve checked everything to make sure, I’ve now got the following out of the car:

Rear seats both bottom part and the backs
All the carpets in the boot
The cover above the spare tyre
The spare tyre/tool kit & jack
Rear parcel shelf and speaker shelf
Metal frame that is bolted in front of the fuel tank

I finally also got someone to drive the car down the road whilst i sat in the boot and it’s definitely from inside the fuel tank at the top right and side

 

[Deleted member 126969]

Not specific to your car, but assuming it is a loose internal baffle, a repair isn’t going to be easy or cheap...so given how far you’ve already stripped it, how much more effort is it to remove the tank? If it’s not too dreadful how about trying an alternative solution - gice it a treatment with something like Petseal Petseal Ultra Tank Sealant 260ml | M&P Direct. Which would bond the loose parts together and stop the rattle. This is a DIYable fix. Cutting it open and removing or welding in loose baffles would very much be a job for someone experienced in that sort of job.

Another DIY fix would be to stuff the tank full of anti-surge foam, but that might be a bit hit and miss depending on where the loose parts are.

Or the obvious new tank of course.

 

[ChipChop]

View attachment 105973

Firstly an update of how the SEC is looking now after a good detail and front and rear windscreen replacement.

I have an issue currently where each time I drove the car I could hear a very odd rattle from inside the boot, I always thought it was maybe a wire hitting against the body of the car or then the rear speaker shelf. I have now stripped the car down 2/3 times and after finally having enough of this rather annoying noise I managed to pin point it down to being from the fuel tank. I have now got the rear seats all out as well as the parcel/speaker shelves and have also removed the metal divider in the boot which sits just in front of the fuel tank as well as all the boot carpets. Each time I hit the top of the fuel tank near the petrol filler side there is a rattle inside the fuel tank which in fact continues for a couple of seconds after too. It seems likes it towards the top right hand side of the fuel tank, I read somewhere it may be the baffles inside but obviously I have no idea what any of that means.

Rather then going to a specialist to have the entire tank taken out for 'investigations' followed by a huge invoice is there anyone that has had a similar problem or if someone knows what can be done without taking the entire tank out, all help will be greatly appreciated!

Phwoar!

They do not make them like that anymore. Stunning

 

[Flyinspanner]

To try a bonding agent, the tank would have to be removed to allow it to ‘slosh‘ about and coat the whole interior.
That may... (or may not) secure the baffle..... or it may just secure it for a short while, until gallons of fuel again slouch about and dislodge it again.

it may be worth contacting a petrol tank repairer/welder and asking about the cost of cutting, repair and resesling. Coat of hammerite before reinstall.

Fuel Tanks - Call Now - Radiator Repair Northern Radiators Leeds NRG

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Contact MB breakers and ask about a replacement tank, again hammerite before install.

you can then decide which route will best suit your needs.

lots of motorcycle places are adept at cutting and rewelding fuel tanks. - there may be one near you.

 

[sarb1984]

To try a bonding agent, the tank would have to be removed to allow it to ‘slosh‘ about and coat the whole interior.
That may... (or may not) secure the baffle..... or it may just secure it for a short while, until gallons of fuel again slouch about and dislodge it again.

it may be worth contacting a petrol tank repairer/welder and asking about the cost of cutting, repair and resesling. Coat of hammerite before reinstall.

Fuel Tanks - Call Now - Radiator Repair Northern Radiators Leeds NRG

COVID-19 UPDATE: WE ARE CURRENTLY OPEN FOR BUSINESS Fuel Tanks ☑ Repair | ☑ Remanufacture | ☑ Recondition | ☑ Recore Simply call free on 0800 002 9625 or email [email protected] UK & Worldwide Service Send Or Arrange Collection Repair Work Many Others Simply Can’t Do We are experts...

radiator-repair.co.uk

Contact MB breakers and ask about a replacement tank, again hammerite before install.

you can then decide which route will best suit your needs.

lots of motorcycle places are adept at cutting and rewelding fuel tanks. - there may be one near you.

appreciate the help, going to make a few phone calls Monday morning now and see what they suggest.