QuestionHi John, Hope you can help.
I have a 1998 740 with close on 200k on the clock.
I hit a very bad pothole recently, and the fuel tank got dented inward, presumably pushing against the pick-up of the fuel pump on the driver's side (Right hand side - South African roads) A noise could be heard, as if the pump was pressed up against the tank. I had the pump checked, and was present when the lid was off the tank, under the rear seat. All was OK, the noise went away, and the car is running fine.
The problem is that the tank has since started LEAKING FUEL through what appears to be a crack. I have used soap to block the leak as an emergency roadside fix, and have tried various adhesives and silicones (gasket maker etc.) to stop the leak permanently, but with no success.
My repairman tell me it will cost a fortune to remove, recondition, and replace the tank. Scary stories of "dropping the differential, draining the gearbox oil to remove the driveshaft, bleeding the suspension" etc are making me nervous.
Any good advice?
AnswerYour repairman is right. It's a very major job.
There are products that are made specifically for patching fuel tanks. I used one a year ago that was essentially two parts of epoxy, and you kneeded them together. Formed a putty that you pressed into the leak/hole, and hardened like steel. My hole (long story I won't go into), was the diameter of your index finger.
I'd look for this product locally or on line, and use that. Another option MIGHT be getting the tank welded/soldered/brazed. Both would be a small fraction of the cost of replacing the tank.
