The emissions air injection pump can seize, causing a loud squealing noise followed by smoke from the drive belt. If the engine is not turned off, the belt will break, turning on the alternator/battery warning light.
Car Problem Reports
Mercedes-Benz 300TE 4MATIC Emissions Air Injection Pumps Can Seize Up and Cause Noise/Smoke
Mercedes-Benz 300TE 4MATIC Problem
Average Mileage: 157,500 mi (143,000 mi - 172,000 mi)
Visitor, 1991 Mercedes-Benz 300TE 4MATIC, 143,000 mi
same deal lots of noises of period of months including grinding squealing belt noise bearing sounds etc
Then seize and big squeal followed by smoke I am looking into pulling pump and using shorter belt
New oem 1800 for pump remanufactured are five hundred...makes no sense for 20 yr old in IL where exempt from emissions. It only works on start for about a minute!
Rattling noise from the hood, Midas diagnosed it and told me to replace the air injection pump. The quoted me $800 for parts (after market) and $300 for labor whereas, online the aip is being sold for $200.00