Turbo issue - w203 cdi

[acf8181]

Bought a 2005 w203 c220 cdi sports coupe last week, all seemed to drive fine but when weather was nice and had pan roof open i thought i could hear an unsually loud 'wooshing' noise when on throttle. Have had a similar engine Merc before so didn't think it sounded quite right. Few days later and i suddenly have a huge loss in power. It's now being a bit intermitant, sometimes full power, sometimes medium, sometimes hardly any!

Am currently working my way through the boost pipes looking (and hoping) for obvious damage, but am unsure if this could be the actual turbo failing and how to test it?

 

[clk320x]

STAR diagnosis could help if it’s something like turbo actuator, throttle position sensor etc

 

[Doggysitter]

+1 for STAR if the boost and vacum pipes are all good.

 

[Joesoap17]

Make sure all intake hoses are secure and not split, if good then is time to worry about Turbo.

 

[clk320x]

Could still be the actuator...

If it is the turbo, no need to worry. You can get a refurbished as new one with a refurb actuator included for cheap now. £200-250ish I’d say, even cheaper if your actuator is ok and you only need the turbo.

 

[wu56Shoozz]

Wow! Your such an expert at this Abs.. why didn't I talk to you before

 

[acf8181]

Thanks for the responses, have spent all afternoon underneath!

So, i found two large splits in the n/s IC hose, one in stock at merc (not cheap, but not ruinous) and changed.

Fixed....er, nope! No more wooshing noise, but it still went into limp mode! If i stop car, turn it off and on, it then runs ok for a while, then does it again?!

 

[HITECH]

I've worked on loads of those specific models and drive one myself a 54 plate one. Wooshing noise most often is a rip in the turbo intake hose. And majority of garages miss the tear in the hose a lot of the time because when its taken off, It looks and feels fine. You have to actually physically bend the hose in half to see the tear which commonly is on the underside of it. I done one specific car that had been in 5 different garages previously. Yes 5 ! Very very easy to miss. When that happens it will start to throw it into limp mode. Will give u about 5/6 error codes pointing to turbo(299), actuator, EGR, throttle position sensor amongst a few others. When the fault is actually the intake hose. A faulty injector can give u similar sounds but u get the diesel smell so if it is anything to do with fuel it is easily found. if no smell of fuel then ide put money on intake hose. A star scan will kick up ONLY all the false errors that this faulty hose causes. One of the garages was a Mercedes garage. they changed every part on the car ACCORDING TO EACH ERROR CODE and the car still had the fault. The codes were set by the hose , When the turbo tried to kick in, it lost air instantly at high pressure. This falsely told the ECU that there was a throttle pedal fault, turbo fault etc etc etc ........... POSSIBLY it might not be the intake hose. This advice and opinion is based ONLY ON MY OWN EXPERIENCE with this specific model. The turbo on them models are quite hardy. Most often when there is a problem with the turbo you will get the common high pitched whistling sounds and it will sound loud when you switch off the car when its spinning down. Ide hold your horses thinking about turbos and actuators and time consuming labour costs until you rule out the intake system and hoses. I will try find a picture of one of the hoses and the tear that happens............

 

[HITECH]

Your next limp mode fault most likely will be your DPF sensor which sits on the back of the air filter box with 2 tubes going to it. (I'm assuming your car has DPF sensor) . Your error code will most probably be 1402 which is the code it kicks up when the sensor goes faulty YOUR DPF ITSELF WILL MOST PROBABLY BE FINE. If you get any codes in the 1400 range leave your EGR alone ( other than giving it a cleanout ). At most your EGR might just need a clean. If you don't have a DPF then your limp mode fault will most probably be your exhaust back pressure sensor which sits just above the EGR valve. When the DPF sensor goes or the exhaust back pressure sensor goes they both give out false errors pointing to a full DPF requiring re-generated or replaced. The exhaust back pressure sensor goes most of the time with the EGR getting clogged up ( because its in the same line ) but will falsely point to the EGR valve. I got a new intake hose last time for £60 and it took literally 2 minutes to fit.
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This is what the DPF sensor looks like (But it will be facing away from you)
Bosch DPF Exhaust Pressure Sensor Diesel Particulate Filter MAP 0281006213 | eBay
(DONT BUY A CHEAPO SENSOR BECAUSE THEY ARE UNRELIABLE)
AND
This is where the exhaust back pressure sensor is (u cant really see it on pic) its just to the left of the EGR (but it sais AGR ON THAT PIC) it will look like a spark plug NUT with a cable plugged into it.
mercedes exhaust back Pressure sensor - Bing images

Thanks for the responses, have spent all afternoon underneath!

So, i found two large splits in the n/s IC hose, one in stock at merc (not cheap, but not ruinous) and changed.

Fixed....er, nope! No more wooshing noise, but it still went into limp mode! If i stop car, turn it off and on, it then runs ok for a while, then does it again?!

 

[acf8181]

Superb information there HITECH, i shall have a look at the things suggested

To check fault codes do i have to take it to a suitably equipt garage, or will one of the machine mart code readers suffice?

 

[HITECH]

Save your pennys for your sensors. No need to go to a garage. ur basic reader will give u the most important faults concerning this. Myself and rest of the techies in here can advise along the way. It sounds all too common with this model. Straight forward fixes. Along the way if you take pictures and put them on here of your engine then myself n others can give arrows and advice, where and how to .

Superb information there HITECH, i shall have a look at the things suggested

To check fault codes do i have to take it to a suitably equipt garage, or will one of the machine mart code readers suffice?

 

[pnevesfoto]

same prolem myself right now!
thx for your precious kowledge and info... going to check everything tomorow and will post some pictures if in doubt...
cheers!

 

[acf8181]

Apologies for delay in the update.

Seems to all be running fine now!

 

[acf8181]

To add, I did buy a cheap code reader anyway but is showing no codes

 

[HITECH]

So what did you change then. Tell in here so that it might help others with similar problems.

To add, I did buy a cheap code reader anyway but is showing no codes

 

[acf8181]

Only the intercooler pipe.....was suprised i had it run on limp home straight away afterwards, but has been fine since

 

[Saeedk1995]

Hi, I’ve been having a similar problem too, took it to like 3 garages so far. Sometimes my turbo works and sometimes it doesn’t (usually on motorways it shuts off) initially I thought it was a problem because of the remap (which was done before I bought the vehicle), so the Mercedes specialists garage mapped it to the latest Mercedes software, which made my engine management lights disappear, but I still have the turbo switching off issue, sometimes the engine management come on and sometimes they disappear. Does anyone know of this is the same issue or this is something different?

 

[HITECH]

Hi, I’ve been having a similar problem too, took it to like 3 garages so far. Sometimes my turbo works and sometimes it doesn’t (usually on motorways it shuts off) initially I thought it was a problem because of the remap (which was done before I bought the vehicle), so the Mercedes specialists garage mapped it to the latest Mercedes software, which made my engine management lights disappear, but I still have the turbo switching off issue, sometimes the engine management come on and sometimes they disappear. Does anyone know of this is the same issue or this is something different?

If its a W203 try unolugging the MAF sensor. Biggest connector you can see just left of middle engine at front. Plugged into big plastic pipe. Try run it for a day with that disconnected. Engine light will come on along with 2 error codes but just ignore. If this hasnt Bn tried. Also the big thick rubber intake pipe just right of engine at the front is a common issue for cracking AND GARAGES MISSING IT coz its not noticed until you swuash The hose hard With your hand Then the crack along the Bottom of it Is obvious

 

[Saeedk1995]

If its a W203 try unolugging the MAF sensor. Biggest connector you can see just left of middle engine at front. Plugged into big plastic pipe. Try run it for a day with that disconnected. Engine light will come on along with 2 error codes but just ignore. If this hasnt Bn tried. Also the big thick rubber intake pipe just right of engine at the front is a common issue for cracking AND GARAGES MISSING IT coz its not noticed until you swuash The hose hard With your hand Then the crack along the Bottom of it Is obvious

It’s a w204, c350 2013, I could check the intake pipe?

 

[HITECH]

It’s a w204, c350 2013, I could check the intake pipe?

My apologies. I thought original post Here started with 203. Not so sure bout trying it with the 204. Not familiar with the 350. Probably has 2 MAF sensors instead of one. Could try disconnecting each one Seperately snd if still the same Try running it with both MAF sensors disconnected but like i say Its a long shot that with the 350.