Mercedes 300SE-1991

The air injection pump has gone bad three times in a 2 years. I have used rebuilt. And what does the smog pump clutch magnet do?

I engages and disengages the air pump using electrical impulse signals from the computer.

Failure on these pumps is almost always the bearings. Is the belt tension at spec?

Benzman

Thanks, Benzman,
I will check to see if the mechanic checked the belt tension.