Idle problem with 1995 E280

Idle problem when? Cold engine or hot?

If it falters when cold the engine's "cold start system" isn't working and needs to be repaired.

If the engine falters when it's hot a vacuum leak may be to blame. Listen to it - for a hissing noise - perhaps from a broken or disconnected vacuum hose. Such a leak will dilute the air / fuel ratio and so cause poor idle but normal driving performance.

Dirty fuel injectors will benefit from an injector cleaner fuel additive; it will improve their flow.

Suggest you find a more open minded mechanic!

Have your Mass Airflow sensor checked.

Get a new mechanic. This "they all do that" mentality is pure crap...

Thank you all for your very constructive suggestions. I'll follow up on all of them.

Much obliged, Galen Pope

I had similar problem on a 94 E320 and turned out to be a vaccum leak on one of the rubber hoses below the intake manfiold.