I seem to be getting hauled along on Mercedes hunts these days when a
friend wants something to run on bio or a big, safe car that gets good
mileage. These are some of the instant disqualifiers. If I see this, we
move on to the next car without even bothering to take it to the MB
--Torn CV boots. CVs ain't cheap and they can be very expensive if
you have a shop do the work.
--Water in the trunk. It has been my experience that this is the rear
window seal rather than the trunk seal. That means there is probably
some rust happening around the window.
--Make sure the cruise control works. Otherwise you are looking at
around $300 to have the amp and the actuator rebuilt.
--Keys. Get as many as you can from the previous owner since dealers
charge up to $50 each to copy them.
--Rust. Get under the car and look. They are usually old. That means
even if you are looking at a car in AZ, it might have lived in place
that used salt on the roads.
--Gauges. Make sure all the gauges work. Odometers tend to be shot.
This might tell you how much stock you should put into the odometer
having actual mileage.
--Open the oil filler cap on the engine and see how much vapor is
rising when the engine is running. This gives you an idea of how bad
the blow by is without having to do a (much more conclusive)
compression test right away. Btw, a worn diesel engine may run very
well. Don't mistake easy starting and smooth running as signs of good
Here in the PNW, a good 123, 124, or 116 body with good interior goes
for about $500 with a bad motor/tranny. If you fall in love with a car
with a bad motor, no matter how perfect the body/interior, remember
after getting the new/used engine in it, it will never be worth what
you have into it. You may think you're going to drive it forever so
it won't matter. And it won't matter, until some asshole comes over
the centerline and turns your car into metal origami. What they gave me
for my mechanically perfect '83 300DT didn't even cover the price
of a good transmission.
I'm sure others will have other things they look for as well.