BrettS

Can anyone tell me what these 2 connectors plug into? I am installing a used engine in my 2003 C230 sedan, 1.8 kompressor. The engine is from a 2004 c230 coupe. I can't figure out what they plug into and I cannot install the engine until I figure it out and plug them in. They are on the drivers side where the engine and transmission meet. The shorter one should be really easy to find because it has to be within a few inches. Yet I can't find either of them. Does anybody recognize these that can tell me what they plug into? Much appreciated!

slammer111

Today may be your lucky day. I think these are the ones you're looking for.

The rectangular one (blue arrow) plugs into some sensor. I don't know what it does unfortunately.



The other (green arrow) goes towards the front L side of the car in the layout shown, and sits below the supercharger and above the engine support. I never had to disconnect it either when removing the supercharger. The only things I can think of are either the AC compressor or the washer fluid pump. Hopefully this is the wire you're looking for as I never looked at the connector at the end.



Hope these help.

While you have the engine and transmission out of the car, here are a few things you should look into.

1. Replace/update the crankcase breather hoses and check valve. In the 1st photo you can see where the valve has cracked and is dripping oil everywhere. The plastic in the valve turns brittle, and the hoses are known to be made of the wrong material in earlier revisions of the engine. The hoses are only accessible with the supercharger removed. While you're at it, replace and top up the supercharger oil.

2. Replace/update the leaking vacuum pump at the back of the engine. This job is much easier with the engine out of the car.

3. Replace/update the leaking cam sensors and add the pigtails. This can be done after the engine is installed if desired. Nice and easy.

4) Replace/update the transmission pilot bushing. The older versions will leak fluid out of the O rings, through the electrical connector, along the cabling and into the transmission controller where the fluid will short out the electronics. Only the newest version (they updated the O rings, and there are at least 3 versions of this part) doesn't leak. The part itself is quite inexpensive. Might as well do this before installing the engine.

5. Replace/update the 4 plastic coolant pipes. This can be done with the engine installed, but access is much easier with it removed, especially for the pipe at the back of the engine beneath the pump in 2). The newest pipes use a different grade of plastic. The older pipes disintegrate and turn into powder. I would also replace the coolant thermostat at the same time. They are a wear item and fail after a few years.

6) Replace the alternator voltage regulator and update the sprag pulley. Nice and easy with the engine removed. Call the dealer with the engine VIN first as there are 2 PNs for the pulley, and they have different dimensions and therefore are not interchangeable. The voltage regulators are known to go bad, and I'm pretty sure your sprag pulley is seized by now.

1) 2) 3) 4) 5) 6) affect 100% of all engines from that era. If they haven't already failed, they will soon. Other than 2) and 6), I would only use OEM (dealer) parts for these repairs, as this is the only way to verify that the parts are made of the correct/updated materials. For 2) there are quality aftermarket alternatives (Pierberg) and for 6) the VR can be replaced with another of the same brand (you have to match the brand of the alternator so it's either Valeo or Bosch). The sprag pulley (both versions) is made by INA and is readily available. For 5) the OEM thermostat is made by Wahler and many aftermarket brands simply repackage this unit.

7) Check and replace the engine mounts. The engine mounts typically last 100-150k km and are most likely shot. The link in 1) above shows how to replace all 3. This can be done while installing the engine. New engine mounts make the car run much smoother.

8) Inspect the timing chain and replace the chain and tensioner and sprockets if necessary. This has a somewhat high failure rate, but seems to be hit or miss depending on the frequency and quality of oil used, as well as driving style. It's much easier to replace while the engine is out of the car, especially if you also want to replace the guides and/or the balance shaft chain which sits towards the bottom of the engine and is "behind" the timing chain.

9) Inspect and replace if needed the 2 rubber flex discs (one behind the transmission, the other to the front of the rear differential) before installing the engine and transmission into the new car. These typically last 300k km, but can occasionally go bad if the car has been abused. Another repair that is very easy with the engine removed, though any shop can do this job with the car on a hoist.

10) Inspect and replace the radiator if it is a Valeo brand. The Valeo ones from that era have a design flaw that mixes coolant and transmission fluid, destroying the transmission. If you have a Behr radiator, this job isn't needed. Once again, much easier with the engine removed.

BrettS

Thank you so much, slammer111. That was exactly what I needed to find them. With the help of your excellent pictures, I was able to locate both of the connectors and they are both plugged in. My stalled project can now get moving again! And I very much appreciate the other advice you also gave on replacing hoses and other parts while the engine is out. Thankfully the transmission was recently rebuilt by the previous owner so some of that may have already been replaced. But I will check all of it out so there are no future issues with any of it. Thanks again!