Hello all - I'm a new owner of a tough old 190D (223k mi. and counting) and while she seems to be running pretty stable given her age, I've noticed the alternator/voltage lite glowing faintly at idle, and found that the main serp. belt is very loose. I tracked that down to the tensioner pully sitting fully slack, and after staring at the drawing in the service manual, said "hey, there should be a spring there." I don't know if it wasn't there when I bought it, or it sprung off to other places recently, but it's gone. The pulley looks fine, otherwise. I can move it with a pliers and tension the belt, which also looks in good shape.
Not wanting to engage the services of the local Euro auto shop to the tune of $500 or so, I've since rigged up a field repair involving some wire and the nearest bolt, but I owe it to the car to do better than that. I know the full tensioner assembly is available on ebay or the parts sites, but since that appears fine (and replacing it would require me to remove the radiator and refit the belt, a task I don't think I'm up for,) is it possible to buy just the spring? Or perhaps the better question is, what size/tension/strength spring is needed, and does anyone know of a source for one?
Thanks much, and keep on rollin' to 500k!