The small hose from in-line fuel filter had been change and reconnected, for a while it looks like we have found the problem, now its leaking again and looks like its coming from under the engine just below the small hose, when driving the car it doesn't leak its only when the car seats for a while. Does anyone know what its call and what could it be? Could itbe after all the O-Ring or the"fuel thermostat????? Anyway!!Does the MBZ 300D 87 have Thermostat at all ???? Thanks in advance for your help!!!

 

Yes this car has the fuel thermostat and they are very prone to leak with high age. Also with high age, the fuel lines can leak. It can be either or a combination. The fuel thermostat can be fixed, it is not necessary to replace the whole thing. There are o-rings available and the thermostat is available. email me if you want both with instructions on how to install them to fix this problem.