slammer111

No need. Found out it's definitely weeping out from within the bell housing, which confirmed my suspicions.

I also crawled underneath and popped off those 2 tiny rectangular covers. Sure enough the inside is slicked with some fluid. Based on the colour I think it's old ATF. I suspect it's actually from the famous leaky pilot bushing.

For more information, click on this thread.

VVF

Hmm.. maybe when they were draining the torque converter (do 2003's still have the drain plug there?) they messed everything with old trans fluid, and later it got flung on the inside of bell housing then.

BTW, sorry to keep asking about the oil consumption, but since you fixed the vacuum pump leak, has the car stopped using oil between changes?

slammer111

2003 does not have the TC drain plug. I actually have no clue how the inside of the bell housing got so wet. Though I thought I read in another thread that the 2 O-rings in the infamous pilot bushing each serve a different purpose. Supposedly 1 ring keeps the fluid from weeping up the electrical connector, but the other may keep fluid out of the housing?

I watched my mechanic do the full flush, to ensure he followed the MB WIS instructions. The bell housing was not touched at all during the procedure, other than the pan and the banjo bolt as per the instructions.

If the fluid in the bell housing is indeed old ATF, then I should have no more oil leaks. Unfortunately I had so many oil leaks over the last few years (cam sensors twice, vacuum pump at least twice) that I no longer have a reference point, as I've been topping up regularly. To give you an idea, I've added over 8-9L (compared to 5.5L) since the last oil change. Yes it's a lot of dead fish unfortunately, but hopefully the problem has been permanently fixed.

I'll be doing an oil change in a month or so, and will fill up the full 5.5L. Only 1 way to find out if I'm still losing oil. Stay tuned, and ask me in 6 months or so.

Fogarasi Barna

Hello,
My name is Barna and i own a MB W203 C180 from 2002. My engine has a strange sound when running. Something like a broken pump or something. I have changed the power steering pump and the sound is still there. Could anyone tell me if my modell has a vacuum pump, and where is it located? Somebody told me that the vacuum pump could make that sound.
Please help me with some infos..
Thanks a lot.

VVF

Barna,
C180 likely has the M271 engine? So vacuum pump is at the back of the engine:
https://mbworld.org/forums/attachmen...p-location.jpg

.. which is actually shown in detail in the first post of this very thread

faddii

is my vacuum pump going? I have had some oil residue on back of engine body for some time before. After, I decided to store car during last winter. I noticed this summer I have oil dripping from under cover..car been parked during this time a side from letting engine run several times and taking short ride around block.

slammer111

Are you sure that's oil? Looks more like the infamous coolant leak at the back of the engine. If your car is low on oil, it would throw an error when driving.

You might want to take a look at this thread.

Good luck.

Norsk_Johnson

Hey man, def looks like it's on it's way out. If it's original, then it's a no-brainer considering these pumps are notorious for failure on M271. The good news is it's a relatively inexpensive replacement and an easy DIY. It could be coolant, but that looks like thick residue and especially since it's all over your transmission as well. Another thing to check would be your valve cover gasket. Over time, and due to high heat, those rubber gaskets tend to dry and crack, causing loss of engine oil around the engine bay. Hope this helps, bro.

faddii

Thank slammer for your suggestion I will review this thread. It does look like a thicker residue more of an engine oil on the floor.

faddii

Hey Norsk thanks for your input..it is the original pump. I didn't know these were notorious on the M271. It does look like a thicker residue more like engine oil. I will keep an eye on the valve cover gasket. It did seem to my surprise seeing engine oil around the engine cap and area. I thought cap wasn't secured well.

faddii

anyone came across this?

RKX Tech C230 vacuum pump repair kit

Norsk_Johnson

This is not a bad solution. However, I have seen guys rebuild with all new seals and have issues with leaking as well. Since it's already a low price part, and if it were me, I'd replace it altogether. Here's a link for a good priced OEM Peirburg.

https://www.eeuroparts.com/Parts/674...ump-724807070/

This was one of my first DIY's after joining this site. Best of luck!

Paul C200K

I tackled this on the weekend. I bought just the metal gasket that sits between the engine and the vacuum pump. After removing the pump (what a mission getting to those bolts!), it looked like the leak was from between the metal gasket (not sure on the vacuum pump side or the gasket side). Feeling chuffed as nuts, I replaced the metal gasket, delighted to have saved R 4 000 (ZAR) on a new pump. Well, after replacing this gasket, it leaks even more now. So much so that I now smell the oil burning on the exhaust and there are drops of oil underneath the vacuum pump. It didn't seem like the leak was at all from the large O-ring though, as that seal had no oil marks beneath it when I removed it. I didn't clean the back of the engine block before reattaching the oil pump, perhaps this has resulted in the seal not holding?! I was also surprised that there were only 2 bolts on the vacuum pump, and perhaps owing to the difficulty of accessing them, I haven't been able to tighten them as much as they should be. I'll give this one more go, but since my C200 is sitting on 272 000 km, perhaps a brand new one is in order.

slammer111

272k on the original pump? That's impressive. Either that, or your pump must've been leaking for years.

My understanding is that ALL M271 vacuum pumps (the earlier revisions at least) start leaking. That's why they revised the design. I do not know of a single person who did not have this problem.

I was faced with the same situation a few years back. Replaced an O ring here and there. In all cases, the leaks eventually came back after a few weeks or months. Threw in the towel and bought a new pump which solved my problem. It wasn't cheap, but it was either that or dealing with a constant mess at the back of the engine.

Just to be sure the leak wasn't at the metal gasket between the pump and engine, I also added a layer of RTV sealant on both sides when installing the new pump.

Sometimes it's easier and less trouble to spend 5x as much but solve a problem permanently.

Paul C200K

Out of interest, in your market was there a w203 C200 kompressor? And what engine is your C230(M271?)? When searching for information on the vacuum pump for w203 it always refers to C230's. My pump had been leaking slowly for a few years, however I only pinpointed it more recently. Although there was oil at the back of the engine, on one occasion years ago the dealership spilled oil all over the engine, and wasn't sure if the oil was from then. Anyway, since replacing the metal gasket it seems worse. I'd still like to try and replace the O-ring as a last attempt before replacing the whole unit. However, the oil seemed to be leaking between the metal gasket and engine, so I'm not sure that that will change anything. Is the metal gasket really the only thing between the vacuum pump and the engine?? If so, it seems that a metal gasket would never create a proper seal? Or is it not meant to? Is the leak somewhere internal (possibly solved with a new O ring?) and then leaking through the pump and out by the metal gasket? Forgive me, I'm not mechanically minded!

RWDlifer

In my experience the metal gasket is rarely the culprit, but that being said, make sure it's evenly torqued and not over tightened. I have reused the metal gasket without leaks.

slammer111

In Canada there were only the C230k (M271) and C320 (V6). In North America they tend to give us only the most powerful variants of a given engine. C180k, C200k, and C230k all use the M271 inline-4, the main difference being the stroke of the engine (ie different piston arm lengths).

For most people, the leak is caused by the failure of the O-ring between the 2 main halves of the pump body. The problem with replacing this part is that MB does not (as of the time I attempted my fix at least) sell that part separately, as it's an "internal" part to the pump assembly. There's one off a Kia Sorrento oil filter that is the same diameter (but slightly incorrect thickness) I was able to use based on someone's suggestion here, but within a few weeks the leak was back. As I had already replaced the other (small) O-ring as well as the metal gasket, I was totally out of ideas. Only the O-ring and gasket are exterior to the engine, so the leak has to be from one of these 2 parts.

The metal gasket has a rubber coating on both sides, which is apparently enough to seal the gap. However, I wasn't taking any chances at this point. Also, there are 3 versions of this part. I replaced it with the latest one.

Paul C200K

Ah, that is interesting. Does yours also come with the renowned timing chain issues? I'm on my third chain, second set of gears. Now that's not a cheap fix!

My leak seems to be between the metal gasket and the pump, but the metal gasket didn't seem to have any rubber layer on it. I only picked up the gasket last month, so I assume it's the latest version. I should have taken a picture once I'd taken the pump off, but since I didn't, I've crafted this wonderful illustration in Paint to show you where the leak comes from . Based on this, could I rule out the O rings, as the leak hasn't occurred between the two halves?

slammer111

The newest official version of the gasket is 2712380180 (that's what my replacement pump came with), though I was unable to seal the leak. I currently have 2712380380 (different version of the same gasket, for other variants of the M271) with a thin layer of RTV gasket maker on both sides. As both versions of the gasket do the same job, personally I would try adding RTV first, and if that fails, then updating the gasket. The 0380 gasket cost $20 CAD (about $16 USD) at the dealer, and nobody else had it.

Just curious, how did you know your timing chain and sprockets had issues? I had mine opened up and looked at last year, and was told the entire timing system was still good (I was at 180k or so at the time). They told me to return at 250-300k.

Paul C200K

Thanks for the info Slammer111. So you would agree the O-rings don't seem to be the issue then? So you say best is to put RTV on both sides of the gasket? I was hesitant about putting that against the engine.

On start up, my car made a noise that sounded like a loose chain being dragged across a surface, just for 1 second, almost as the revs settle back down after switching the car on. That being said, even after the chain and gear change, my car still makes that noise, but to a lesser extent. I had my chain and gears done at around 180 000, and chain done a second time around 250 000. My father has the W204 C180, his car started making quite a noise on start up around just before the 120 000 km maintenance plan ran out. He took it in to the dealership, they measured the chain and said it was still within tolerances, so MB head office said they weren't prepared to replace it. The local dealership though insisted that it didn't sound right, so they actually sent a voice clip to head office of the start up noise. Based on that audio clip, Head office agreed and authorised the replacement at their cost. That was just over R 30 000 (or 2 700 of your monies!!) Not sure if it's the same in your car, but my C200 w203 and my dads C180 w204 have a single chain, so it stretches. Don't know why Mercedes didn't make it a dual chain like in some other models, as this was a known flaw in the design.

slammer111

The leak can come from either the large O-ring between the 2 halves of the pump, or the gasket. For me, the O-ring died first. However, I decided to replace the gasket as well. The original 2712380080 gasket is quite inferior (it's literally a rubber seal). After a pile of fiddling, i decided to get the latest version of everything.

Yes the timing chain is a known weak point, and has taken out quite a few vehicles with the M271 engine. Too bad there aren't any double chain solutions, though there are now aftermarket sprocket and chain solutions.

forcejb

Set out today to replace the brake vacuum pump. But I can't get the fitting off the connection on the pump. I squeeze the circular ring which should release it, but simultaneous upward pressure fails to move the fitting off the hose barb. Please help.

slammer111

Make sure you're squeezing the 2 tabs where the ring meets the connector. A pair of pliers may help if you can't squeeze hard enough. Then it's just a matter of twisting and wobbling the connector off the pump.

Ricardo Oros

I was told I had a small vacuum leak so this might help me thanks !

Danny2569

Hi everyone, tackled this job today which was easy peasy thanks to this thread!

One thing I wanted to query on though, I have attached a photo of where the vacuum pump attaches onto the back of the motor and in one of the holes there was a build up of gunk. I cleaned it out and it was a small amount of sludge which looked like it was blocking the hole, only very thin but evenly distributed to where it had complete coverage.

My question is, does anyone know exactly how these things work? Is there a dead spot in this part of the pump with the sole purpose to gather this sludge? Is this something I should look into further?

Just hunting for a bit of information so any is appreciated