Mercedes-Benz C-Class W202 Mine Is A Perfect Example

If you take your time, you can still find a smokin’ deal on a W202. Mine is a perfect example.
 

Years ago I had a 2000 C280 sport. I had it for a number of years, and used it at track days all over the midwest. It wasn’t blindingly fast, but I got up-close and personal with all things W202, M112, and 722.6. However, it had quite significant rust, and in 2018, I sold it.
 
I missed it dearly, and for the past year or so, I began to search for a clean C-class once again. Personally, after dealing with midwest rot, I decided that the main criteria to start with was a rust-free (or at least mostly) car. I preferred a 6 cylinder, so it was going to be a C280 over a C230. I had nothing against them, I just prefer a half dozen pistons.
 
So in my mind, I created my own buyer’s guide. It was quite simple. Start with a clean car. After that, check for any noise from the engine, and check for any leaks from the transmission. Lets dive into those a little more.
 
Rust is a huge concern for me when getting a C-class. Because they rust essentially from the inside-out, rust is hard to mitigate and almost impossible to stop. Doors and fender gaps usually go first. Jacking points are another concern, especially in the later facelift cars. Rust on rockers will hide under the nice looking rocker cover. You’ll also want to check out the front spring perches for any rust too. Otherwise you’ll be watching a spring shoot out of your hood. (Not really. Kinda.) So unless you’re really interested in learning bodywork, get a rust free car.
 

Engines in the C280 tend to be very stout. The M104 and M112 are both legendarily reliable. The M104 has a few items to check, though. M104 engines had a solid run from 1993 through 1997. Silky smooth and good on power, these engines are reliable, and thankfully still have plenty of parts support. Their weak points come from the outside of the engine.
 
As with anything that is now encroaching on 30 years, you’ll want to check things thoroughly. But pay particular attention to a few key areas. The rear main seal on the M104 might not be able to be replaced on its own. I found out on my engine that the seal outer diameter was different from the crankcase seal that houses the seal. It’s not expensive, but worth buying the whole thing if you have to dive in there. Up front, the timing cover seal has a tendency to go bad and leak. Additionally, the water pump may need to be replaced as well.
 
Electrics of the engine should be done as a precaution. Crank shaft sensors can go bad, leave you stranded, and won’t cause a check engine light. Ask me how I know. And MAF sensors can sometimes need attention, too. Check the connections in the fuse box as well, especially for the aux fans. In essence, if you’re getting one of these, replace the sensors as soon as you can, and have a few extras just in case.
 
M112 V6’s are a similar story. The rear main seal leaks, but that can be replaced as standard. The water pumps have a tendency to last about 120,000 miles, too. These cars however have a tendency of leaking from the valve cover gaskets. Otherwise, the M112 is the “better” engine. But there’s an argument to be made about that. Both make about the same horsepower and torque, so you’re not left in the dust by choosing one over the other.
 

Power from both of those engines is sent to the iconic 722.6 transmission. Only very late cars will have the manual control version of this gearbox. While strong, there’s some things to know about the 722.6 when checking out a car. If you’re looking at a car that needs a bit of TLC, as I did, a “bad” transmission might only be low on transmission fluid.
 
Low fluid will have a few key symptoms. The car might be able to move, but it’ll bang into gear. And when it’s in gear, it’ll feel like it is slipping. Because it is. You may also get a check engine light. Because the TCM sends codes to the ECU, you may not get an accurate reading from the OBD port. The TCM must be read by a Mercedes compatible scanner.
 
Signs of an actual bad transmission include shuttering once in gear. This is a sign of the clutch packs going bad, which transmission fluid sadly won’t fix.
 
Leaking from the transmission is very possible, too. A transmission fluid flush kit (which you should buy anyway) will have the filter and the transmission pan gasket. That gasket leaks often, and is a simple fix. But you could also leak from the front pump seal, or the gear input plunger at the back of the transmission. Both require a transmission-out fix. But the parts are dirt cheap, and it can be done in a day.
 
So, if you’re going down the W202 route, the best option is to start with a clean example, and then go from there. Sadly, there’s no value to be built by restoring anything other than a C36 or C43. So you’ll find a lot of C’s you’ll want to pass on. But when you find the one, you’ll know it.