I have a 1979 W116 300SD. I don't care for the USA style headlights so I put together a nice set of European headlights from the several sets that I have. I was so excited to install them and they look so good!

When I installed them I had to remove a black plastic "shield". Right after I installed them my car began running sluggish. Normally it drives like a rocket but now I floor it and it barely moves. It feels like it is dragging an anchor behind it!

So today I checked the fuel prefilter (which looked clean and clear) then I replaced the main fuel filter thinking maybe that was the cause of lack of power. The fuel was dark, so I am glad I replaced the filter.

Right when I was bleeding the fuel lines the starter started spinning without turning the ring gear. This would be the third time it has gone out this year. No more CSK rebuilt starters, even if they are under warranty!

I ended up installing an old, dirty Bosch rebuild and after two different Schuck's auto stores and talking to the right people I got a refund for the starter instead of another warranty for a starter that will only last 2 months!

I got the car running again but it was still slow. Then I realized the reason for the poor performance was coincidental with the installation of the European headlights. On this car the air intake comes in behind the right headlight.

The USA headlights "float" and allow air to flow behind them into the air intake tube. The European headlights fit flush against the body and seal the area behind them (where the air intake is). When Euro headlights are installed they seal off the air intake area! No wonder the car seems slower and I am amazed it runs at all!

Now I am angry because I don't want to have to be stuck with putting the USA lights back on. I don't know what to do about fixing the air intake so it can breathe. I could install an aftermarket cone filter, but all that does is suck in hot air and debris. Maybe I could route a tube from the air cleaner to the front of the car.

This is frustrating. Who would have thought installing Euro headlights would affect the engine?