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About to buy W203

1131 Views 6 Replies 3 Participants Last post by  kuseetha
Dear friends,

This is my first post in this website. I am from Sri Lanka and I am a car enthusiast. I own two Alfas thus somewhat competent with small DIY things but new to Mercs.

My uncle is looking to buy a W203 (that is what his budget allows) and he asked me to find himself a good car.

Since he hardly drives faster than 50km/h (on normal roads) and never above 100km/h (on expressways), I suggested him a C180 non-supercharged model (one less component to worry about and better fuel economy) with an automatic trans. He is 63 this year.

As M271 seem to have issues, all our shortlisted cars have M111.951 engines and I guess the 5g tronic trans. (Made between 2002-2003)

I have read many posts and noted a few issues with these models
1. Valeo radiator leaking coolant to ATF eventually failing the transmission
2. Cam angle sensor leaking oil to wiring harness causing other sensors to fail
3. Head gasket issues
4. Worn suspension

Since we are going to inspect these cars soon, I would like some advice on the following:

1. How to visually identify whether the problematic radiator was replaced or not

2. I have read that some solution is available for this cam sensor wiring oil seep issue, but how to identify whether some damage has been already done or not? Or whether this was already fixed?

3. Does this have engine and transmission oil dipsticks?

4. I have a simple ELM327 code reader with android app. Where is the OBD2 port located?

5. Does these have any liquid filled mounts or suspension components that are prone to go bad and are short-lived?

6. Does this model have any crucial parts which are in short supply?

7. Where to find the workshop manual and the parts catalog with diagrams on this site?

Thank you very much

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Here in the USA, MB stopped putting in oil dipsticks from 2003 onwards. The transmissions, on the other hand, don't.

Be prepared to do a complete front suspension overhaul. At the present age of the W203, they're going to be due for this, and it's true of any car. This is due to bushings, ball joints, and shock absorbers simply wearing out after 15-20 years. Fortunately, suspension overhauls are not difficult to do.

I don't know about head gaskets--Wikipedia talks about the original Victor Reinz head gasket having some issues--but I do know that the valve cover gasket will need replacing at this point, again, due to age. That's not too difficult, either.

If the car you're looking at has an automatic transmission, then you'll also be looking at a transmission fluid and filter exchange, along with the transmission electrical connector bushing. This is normal on 722.6 (5-speed) transmissions and is easy to do.
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I'm not familiar with Valvoline Maxlife ATF fluid, but as long as it meets any of the following specs:

  • 236.10
  • 236.12
  • 236.14

then you'll be fine. The best way that I've found to exchange the fluid is to disconnect the return line at the radiator and use the transmission's own fluid pump to get the old fluid out and new fluid in, 3 litres at a time. With these cars, the radiator also cools the transmission fluid as well as the antifreeze/coolant fluid. The procedure to do this is best done with two people, though I have done it alone.

A lot of the following likely will be familiar since you've worked on other cars.

1.) Drain the pan and then pull it off to change the filter. If need be, replace the rubber gasket for the pan, but it probably just needs cleaning. Wash the pan (and the magnet inside) with hot, soapy water and allow to dry.

2.) Put the pan back on and fill the transmission with 4 litres of fluid.

3.) Get a 3 or 4 litre plastic bottle and possibly some flexible rubber tubing about 30 cm long and about 1cm inner diameter. You'll need this for the next step. The tubing can be the cheap clear stuff; this is not a high-pressure situation.

4.) Disconnect the transmission return line, preferably closer to the radiator. You can do it at the transmission bellhousing, but it's more of a pain there since that's a banjo fitting. There's another fitting that, IIRC, requires a 15mm and a 17mm open box wrench to loosen. Transmission fluid will come out of there. Have your flexible rubber tubing ready to slip over the end closest to the radiator. The other end of your rubber tubing should go into the 3 or 4 litre plastic bottle.

5.) Start the car. Old transmission fluid will come quickly out of the return line right into the plastic bottle. While your at it, shift into reverse, neutral, and drive. Using the Tiptronic shifting, move through the gears as best you can until you get to 3 liters of old fluid evacuated out. When you do reach about 3 litres, shut off the engine and find a place to empty that bottle of old fluid. I use the 1-litre ATF bottles that I had previously used during Step 2, along with a funnel to help avoid spillage.

6.) Fill the transmission, from the top, with 3 more litres of new fluid.

Repeat steps 5 and 6, going 3 litres at a time, until your transmission fluid starts coming out nice and red. It may not look 100% clean, but it should look a lot cleaner than it had.

Now you should've gotten a good amount of the old fluid out. Check the level of the transmission with that new dipstick that's on the way. There are two marks on there, 25 deg. C and 80 deg. C. Since the fluid's not warmed up just yet, you'll be looking at the 25 degree marks to check proper level. Add a little if need be; remove a little if need be.

Then, go for a drive to get the transmission up to operating temperature, which is 80 Celsius. I'd say about 10 km should do it. Then, check the fluid using the 80 Celsius marks on the dipstick. Add a little or remove a little as need be. The 80 Celsius marks are the definitive leveling test.

And you're now done! :)

I would suggest doing this maintenance in another 60,000 km. This will help keep your transmission nice and happy.
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