Hi Rian!
I work in a garage that specialises in W123s, W124s and 190s
Don't know if I'm the right guy to ask.
Unlike many cars, 124s tend to rust rather perfidious. The underside is covered with realy THICK PVC undercoating - which tends to hold it's form even if there's a 4"x4" rust hole underneath it, giving the impression of bodywork that's long gone. Though the realy important rust traps are few, if really important. Mainly the front spring perches and the front attachements of the rear sub-frame next to the wheel well (triangular mounts). They present a danger if rotten.
I've once put together a little horror picture show of W124 rust. It's in german, but I think google translate does an OK job of translating it.
www.motofreibeuter.de/?p=7536 - don't be scared off by those pictures, they are all extreme examples. However they highlight the main issues with w124s. So if you like to buy a keeper, it's worth looking at all those bits, as far as possible. Rule of thumb; the later the build date, the worse the bodywork...
The other thing with wagons is; the hydraulics. Or mainly all the associated pipe-work. If all the hard lines are rusty and close to breaking, it's a LOT of work to replace them all and shove them past the rear suspension... If the rear suspension is bumpy, it's the nitrogen spheres that need replacing, not the shockers (as many garages tell). On a wagon they'r a bit of a pain in the rear end to replace, if nuts & pipes are rusty, it's often the case that the drive shaft on the right side needs to come out etc.
The diesel engines are more or less all very robust and hardly ever cause issues. The late multi-valve diesel engines (from '93 on) can cause more problems. They have plastic fuel lines which tend to leak air. Though once replaced, they last a while. The other issue is glow plugs. They can get stuck and break off (they are very long & thin). Which means a bit of trouble. and finding a specialist who can drill them out. Next, if smaler issue, is the engine wiring loom. It's just the same as with the multi-valve gasoline engines; the multi-valve diesels also suffer from decomposing wiring looms. Only the don't cause runing issues. However, pre-glowing may fail due to shot wiring. The diesel wiring loom is about 350-400€, so about half the price of most gasoline wiring looms (if available).
Which sort brings us to the next problem of W124s; the late multi-valve gasoline engines. I'd stay clear of them. Even if they are tempting for they'r horsepower and slightly better economy. Unless the engine wiring loom has allready been replaced, since they'r expensive. and in many cases the ECU is toast too, if wires shorted. Throttle bodys can be faulty as well. So - if things have been replaced, a multi-valve gas engine is an option. However; stay clear of 5-speed automatic transmissions. They are trouble and missbehave frequently. The 4-speed autos are proven and - if maintained well - almost bullet proof.
Beyond 300.000km milage, it's worth to consider a full rear suspension rebuild. It'll still drive good, but with rebuild rear suspension it'll drive lovely. if budget allows, a front suspension rebuild is also not a misstake. and then it'll drive fantastic
What's worth replacing in any case - the front ball joints!! If they'r worn out, they separate (sort of a stupid design - the spring pushes them apart!) and the wheel will fly off to the side... Neither pretty, nor very safe!
data.motor-talk.de/data/galleries/0/2/8527/38152008/traggelenk-2-1084284569635607417.jpgAnd a recent development regarding spare parts; the infrared flip-keys are not available anymore. So watch out if you buy an E-Class with infrared key/flip key.so that's a thing to be aware of.
Sooo - hope you've not fallen asleep yet
That's the main things covered, the rest is just regular used-car-buying stuff really. Be carefull about rust on the critical parts and all the pipe work. And be double-carefull when buying an E-Class from '93 on. They lack in generall build quality and seem to much more prone to rust. Best years are '88 to '92. Whilst they'r great cars - they are also complex cars, I'd say they are sort of the first "modern" car of Stuttgart origin. Fully electronically controlled interior heater and other electronic gizmos.
I've now driven an total of about 150.000km in W124s in the last couple of years - and I'm still enjoying driving those cars. With regular maintenance and care they can last a long, long time - without much trouble.
Hope you'r a bit more clued up on 124s now
Cheers,
Jan
PS: during final exams we had a play of words; "can Jan?" - "yes Jan can, because Jan is a can-Jan [read: canyon]". Happy times!
You've just reminded me of them
