'91 560SEC, '91 300SE (sold), '98 Yota, '02 S-10 Hauler
An excellent rundown on critical issues with 126 cars. Let's not forget the old rubber fuel lines both under the hood and out back at the pumps. Several have lost their cars due to old rubber rupturing and the resulting Car-B-Ques weren't pretty. One of the biggest things about these 30-40 year old cars is/are they ARE old and if not properly maintained over the years they will eventually bite the current owners. I'll agree 100% that when properly sorted these TOP of the line road machines are a dream to drive and ride in. What other car can you do a 400-500 mile road trip and not be exhausted on arrival at your destination.You're welcome.
Oh boy, problem areas. Where to being?!
If the a.c. doesn't blow cold it's not "just a Freon refill." It never ever is. It's going to be a $2500 ac rebuild. Every time.
Front end stuff is almost always neglected so expect to need control arms, ball joints, etc. Buying a 126? Time to rebuild the entire front end!
Rust underneath the rear window is a big one. Pull the rear hat tray and also get in the trunk and inspect by hand. You typically cannot see it with the naked eye, even when it's catastrophic. You need to get in there and feel by hand. Plenty of threads here on this topic. Both of my 126's are rust free, but both were always garaged (one in CA and one here in NC) and never driven in snow.
One huge piece of maintenance that is always avoided is the timing chain, plus guides and tensioner. Again, lots of threads on this. If that has been tackled in the last ten years or 50k miles and genuine Benz parts were used that's a huge plus. If not you WILL need to do it. And expect to pay around 2 grand, depending upon where you are located. Absolutely NO non MB parts for this job! Non MB chains can snap and guides shatter or split. Save and buy Febi? Enjoy your engine when it grenades. Genuine MB parts for this and drive worry free.
The rear SLS suspension tends to get neglected and a lot of shops don't have a clue hot to fix it or even diagnose it. Lots of threads here on this.
$6500 is not much of a budget these days. Three years ago you'd be fine. You will no doubt need to spend thousands to sort out whatever example you find (unless you find one like mine that was just given a huge sorting). I don't want to discourage you, but I want you to be realistic and understand that you need to be patient and careful. Don't rush! It can take time finding a good car.
Being on the east coast makes it hard. Most of the good ones are out west.
My present 560SEC came with a stack of repair/maintenance tickets but right off the bat I had to change the old rubber fuel lines, flex discs on the drive shaft, and several parts on the front end. I guess all told I've spent in 6 years almost what I paid to buy the car and it's very well sorted now. Not meaning to scare but just a heads up to find the best mechanical shape car you can afford and take care of any issues as they come up