Russell Ormerod

If you only have a fault code for air injection. Then you may have suffered engine damage. First step is to check if all cyl are firing. Use a ir thermometer for that. Get it connected to a sds. Check faults and event memory

AlexMercedes

When it was connected to the STAR/DAS, all cylinders were shown to be perfectly working, all of them fired up on all startup tests. The event memory showed the misfires, presumably from the past that have not been cleared yet. The only thing the check engine light is on for is the secondary air injection, no other error. At this point, I'm thinking there is something wrong with the exhaust system since there was a lot of raw unburned fuel being thrown around in the exhaust when the car was operating for 4 months straight on 6 cylinders. There is also this noticable fuel smell coming from the exhaust, as well as some clingy noises from the exhaust at idle. I was told there shouldn't be engine damage though.... Anyway, thanks for the help

Russell Ormerod

Do you really think that if enough fuel makes it to the exhaust. It's not going to damage the bore after 6 months. By then your sump will have more fuel in it that oil. Forget about your exhaust issue. Clear all faults and events. Road test and recheck. I am will to bet you still have a misfire. Where did you look on DAS for all cylinders running? Show me the page pls. Are they all zero?

Welwynnick

Are you still miss-firing?
What's the condition of your spark plugs?
Do you know if your IC pump is working?
Can you measure IAT's?
Nick

Russell Ormerod

The has no power from cold Measuring IAT is not going to achieve anything mate. And anyway a code will be set if IAT is too high.

AlexMercedes

I am not getting any misfires, haven't got any misfires ever since the voltage transformer and coil pack have been replaced.

Welwynnick

OK, if there's one thing these engines are good at, is detecting misfiring.
Do have a way to read ignition advance, like an OBD2 reader with a plotting function?
Have you tried temporarily disconnecting the battery?
Nick

AlexMercedes

I don't have any devices that can do that, but now that you mention the battery, it is old (from 2009) and died not too long ago, saved by a jumpstart. But, I don't see how the battery would cause lack of power...

tusabes

Either your turbos are dead or cats are ruined and you're exhaust is plugged up


Why don't you simply disconnect the exhaust and take it for a run to eliminate that issue ?

AlexMercedes

I dont think it's my turbos, I can hear them when I floor it. The car completely loses its power after ~2500 rpm, but I can still hear the turbos.

I was thinking of replacing the cats and muffler temporarily with straight pipes and taking it out for a test. If I didn't mention before, my right side resonator was completely destroyed after the misfires, so it isn't unreasonable to assume that it must have also damaged other exhaust components. Before I do that, you want me to do anything else?

tusabes

Straight pipes will be good first step to test

AlexMercedes

Just a quick question before I do that:

Does removing the mufflers alone make you lose horsepower or is that just a myth?

And I know that removing the catalytic converters alone would increase HP and TQ, even if my car isn't having this loss of power issue. I'm really interested into seeing if a straight pipe will fix my problem and/or how this will turn out.

Welwynnick

If the turbos were dead, they would probably be seized in the housings. The oil flingers wouldn't fling any more, and oil would pass from the bearings along the shaft to the turbine. Then the oil would burn, creamating the turbos and chucking out LOTS of smoke. Ask me how I know....

It is beginnning to sound blocked cats.

There's one other thing to consider though. Could it be a boost leak - especially on a tuned car? Mine is Eurocharge tuned, and I needed to replace the jubilee clips on the turbo outlet pipes with T-nut clamps, just to avoid leaking.

Since at least one of the coil packs has been replaced, that means several of the rubber/plastic hose connections wil definitely have been disturbed. Check out their condition. I think in general its definitely worth inspecting and cleaning the joints and fitting new jubilee clips as a matter of course.

Nick

AlexMercedes

My car is Renntech tuned, so I could consider that as a possibility. Although I would first start off straight piping the car and see if that does anything.The fuel would be clogged up only in the cats and nowhere else in the exhaust system, correct?

Welwynnick

That's up to you.

Checking the inlet pipes is much quicker and easier than changing exhaust pipes.

Nick

AlexMercedes

Thanks, I'll get to that really soon. Also, should I just forget about the secondary air injection problem? I need confirmation that that's not the issue so I won't go off spending money on it for no reason...

maximus16v

Hi

I read through the thread and seems like consensus is cats/exhaust.

Might sound stupid but I'll throw this in: ever consider the accelerator pedal? I don't know much about these cars but maybe someone here can see a connection if there is one. Only reason I say this is because I just bought an 01 S500 from the original owner and I pulled the history summary from local MB dealer and one recent line item was complaint of loss in power and the fix was replaced accelerator pedal (probably switch or something?). It doesn't go into detail but thought I would just throw that out there as I found it odd when I was going through the history.

tusabes

Yes the accelerator pedal is a common failure item and could have failed as a coincidence

AlexMercedes

If it were the acceleration pedal, won't there just be a delayed response in throttle instead of the car actually losing power? I'm not too sure about it, so correct me if I'm wrong.

tusabes

You need to start actually doing the work to rule out issues and then post questions after you've tried what's recommended

You haven't done the intake and exhaust work yet to rule those out , do them then post an update if it doesn't reveal the problem

Russell Ormerod

Clearly you have very little knowledge of how to diagnose and repair this car. It is a very complex system. Leave it to an expert before you cause more damage.

AlexMercedes

I have finally resolved the issue. Turns out all this nonsense, headaches, and overall b*ll**** was only because of a defective MAP sensor. My original one was already broken, and when that one got replaced, it was replaced with a defective one. Like an idiot, I ruled out the possibility of a faulty MAP sensor because it was just replaced, but who knows if it works in the first place. I think I just have bad luck with this car, the same exact situation happened with the coil pack a few months back where a defective coil pack was put into my car.

Now the car has a stupid amount of power compared to before, it used to get 0-60 in 10 seconds or more and now it does it under 4.5 (thanks to Renntech ECU). Thanks for all your help guys.

tusabes

Where is your mechanic getting his parts ? That many defective replacement parts is a problem . And it's unheard of if it's genuine Mercedes parts

Are you buying used parts on eBay or Is your mechanic buying used or new parts ?

Are you sure he isn't buying used parts and charging you for new parts ?

AlexMercedes

I moved away from my mechanic, it seems like he's become an unreliable source. Only thing he can really manage are basic things like oil changes, filters, etc.

I found an MB master certified technician who once worked for MB and specialized in repairs, and he seems to know everything about these cars. It took him a while to figure out the problem because it was easy to rule out a brand new MAP sensor, but he eventually figured it out. I won't be taking the car in to amateur mechanics anymore, this MB trained mechanic has a lot of knowledge and experience with these cars compared to an amateur. I'll also be planning to do mostly DIY jobs in the future, as this MB dude charges a little too much for labor (which is expected).

fastlife23

What kind of answer are you looking for? Not to be a dick but there seems to be some really good advice in here to get to the root problem and you have not taken any of it?

Tusabes started with some and you completely ignored that.

Plus who drives a car for 6 months with a misfire?