Im looking to upgrade from my daily driven C230 Kompressor to something a bit more powerful and refined. It seems the C36/43 AMGs have come down enough in price for me to finally get one of these lovely beauties.

I have extremely limited experience with this brand in general, im an ASE certified master tech and a decently smart guy, some things would need to be left to the dealer, of course, but as far as removal/installation of parts i am sure i can do that myself.

Im basically wondering what are some common issues these cars have? What things have a tendency to fail at certain mileages? Basically things to look out for. I didnt see a sticky on this.

 

Watch out for engine wiring harness on early C36 models.

 

Look out for Transmission issues on the C43. We get that issue at the shop at around 100k sometimes. It can very hit or miss with the C43.

 

I only have experience with the C43, so my comments will be limited to it and not the C36.

Rust, but that's hard to figure, really depends where you live and what the car's been through.

Oil cooler and oil pressure test port gaskets on the C43s can harden over time and mean leakages. Messy, but not a huge job to sort out. Just be sure to track down the parts - the little oil cooler seals are stupidly expensive at the dealership, but only just an arm and a leg elsewhere.

Seems there are some power seat issues that can come up once in a while, but again a relatively easy fix - typically the 'comfort' relay. The pneumatic seats on the C43 can sometimes be an issue - hopefully just the air hose has come loose.

Front lower control arm bushings may be worn or broken on higher mileage cars (and most of them will be higher mileage nowadays). There will be low speed clunks. The bushings might look okay from a brief visual inspection with the control arm still on the car, but you really need it off to see exactly. One of the bushings on the arm isn't solid rubber all the way around, but rather has 'spokes', and those spokes can rip. Doing the bushings means control arm has to come out, which means the spring has to come out, and because there are eccentric bolts that hold the control arm in, it means an alignment is required once everything is back together. Solution - buy lowering springs and upgrade at the same time. Might as well do the shocks at the same time too, and perhaps the drag link, or at least the steering damper and ball joints too. Doing all that will make the car feel substantially new again. Some, including myself, have used the KMac adjustable camber/castor bushings at the front for the adjustibility. However, these tend to squeak (at least they do on my car) so keep that in mind if it's going to annoy you.

Trunk lock - on my car, in cold weather it will just pop open on its own. Not good! Solution - either buy a replacement (VIN specific, and about $600 last time I checked) or just manually lock it during the winter months. Or just don't drive the car in the winter...

Fuel level senders can go bad and lead to wonky fuel level gauge, ie. showing zero when the tank is actually full. My car did this for quite a while, but it appeared to fix itself somewhat after several months of my ownership - I ran premium all the time, perhaps the previous owner did not? No idea.

Hot starting issues can be related to the crank position sensor. Only one small torx bolt holds it in place, pretty easy fix. Other driveability issues are typically MAF sensor related - keeping a spare handy might be a good idea.

Previously mentioned were the transmission issues. I've never experienced any major catastrophe. Best to flush it out, but keep in mind that to flush out the torque converter will require removal of the driver's side primary cat and downpipe - it blocks access to the torque converter drain plug.

The large electrical connector on the transmission can be a cause of leaks too. Relatively cheap part (sub $30?) but easiest to get at (with sufficient leverage) with the car on a hoist, as opposed to lying underneath on the garage floor. Less claustrophobia too.

Watch for the little C43 specific cross piece on the lower grille on the front bumper. I'm sure it's bloody expensive to buy a new one. I drilled several small, neat holes and secured it to the grille proper with stainless wire. Just in case.

Speaking of the front bumper, the edges are quite low and can catch crap on the road, or curbs and whatnot. The car uses the normal 202 bumper skeleton, but with AMG specific mods (you have to cut out certain portions to make it fit the C43 bumper skin). Pain in the butt to do, so look at the edges of the bumper. If they are low or misaligned, it could be down to broken plastic rails on the edges of the bumper. This is a major concern for me because I could not find the piece for sale in Canada, only with American based online retailers. The part is about $125 shipped in the US, but they won't ship it up. It's large. I've picked up two from the US and brought them back over the border. Big pain. Solution - don't let relatives drive your car.

If in a winter climate, keep in mind there is no provision on the block for a standard type block heater. Have to use an oil pan heater - I've used the Wolverine brand. Unfortunately, the capacity of the lubrication system suggest I use a larger pad, but I could only fit a small, narrow one on the leading edge of the pan, as the rest is finned for cooling purposes.

The thermostat is a pain to get to with the rad in place. Apparently, so too is one of the water pump bolts (I always did mine with the engine out).

Front brakes rotors are very expensive. Budget for them (like $200-300 per side if OE) or find cheaper alternatives such as W203 non AMG Sport package rotors.

Budget for the spark plugs and wires - there are 16 of them.

Avoid buying the cheaper brands (like Meyle) for replacement valve breather hoses. Mine split after just a year of doing nothing (the car sat). Same comment for the fuel pump, get Pierburg or don't bother.

 

add - wiper motor should be lubed , 18 wheels may loose cruise control, budget for coils

btw, I have that trunk issue on my E55, did a search and no one seemed to ever of had that problem.

 

Saabateur-

Thanks for taking the time to list out those items. I bought a C43 last week and am in the process of baselining the maintenance and fixing the oil leaks. As you stated, I replaced the oil cooler gaskets - but didn't do the oil pressure port. And that darn oil pressure port seems to be the problem as it still leaks! A project for this week!

That is a great list!

 

Another note - the test port gasket, and the crank position sensor, have different styles depending on the serial number of the engine. Make sure you buy the right one! Engine serial number is near the bell housing, on the passenger side if memory serves. Easiest to get at with the airbox removed.

Also, for DIY transmission fluid changes - need to get the dipstick tool, and an IR thermometer. There's a good DIY on the 'other' Benz forum, in the W210 section.

 

I love my C43 with 190,000 miles, it was looked after and had a good service records come with it.

Just minor things in my 2 years of ownership... steering shock and a flex disk.

buy one! they are great, just make sure it's been looked after and get an inspection my a mercedes specialist