Gas Tank Cleaning

[UPSTATE NY]

Hello, I have a 76 450SL, I haven't had it running in almost seven years. Last year I added gas to the tank and the guage didn't move (it was found to be stuck). The fuel pump failed. I removed the sending unit and found that the old gas had turn into a paste like substance covering the inside of the tank. No rust, but defintiely a foreign substance was now present.

Has anyone had any experience with a dirty tank and how it was repaired ?

A new tank is prohibitive ($1400.00).

I would like to find a way to clean the tank without removing it.

I've been told by a very good source to add a gallon of carburetor cleaner into the tank with some gas and let it set for two week then rinse the tank out with clean gas. The same person said that lacquer thinner would be bad for the inside of tank.

I've got a new fuel pump, filter, etc as well as new injectors, I'd hate to ruin them with tainted gas.

Any info would be appreciated.

Thank You
JOB

[HitParader]

You could check to see if any local radiator shops will "boil" out the gas tank for you (I think they submerge it in caustic soda or similar). That used to be the way to restore gas tanks, however with environmental laws changing over the past decade or so I don't know if that is still permitted. But it really works, you can even weld on a tank that has been boiled out. Of course you have to remove the tank from the car to do this, it's usually a pretty easy but dirty job...

Would also recommend using a liquid tank liner in the tank after it has been cleaned, it will seal the metal and prevent future corrosion...I forget the good brands but they are always advertised in Hemming Motor News.

[ctaylor738]

Definitely get it boiled, or find a used tank.

[matt7531]

I don't think junkyards can sell used tanks. Good luck.