Mercedes C220 CDI - Easy to Fix Leaking Injectors?

Make sure you have tools to fit the injectors. I've run out of fuel on my tractor and cracked the fitting on top of the injector until I got fuel. I've started cars the same way just have someone to crank while you bleed. These were all mechanical systems.

Haven't worked on the Mercedes, but it is a rail system vice having the injector tapped into the head. So in this respect it is largely similar to a gas injection system.

Peek under the hood, confirm what your manual says, ensure you can get the tools and the proper bushings (2 per injector) and you should be good.

The rail actually holds the injector sandwiched between itself and the intake, with two rubber bushings providing your seal.

So if you can get the rail off, you are golden.

Are they Rubber seals? Mercedes said it was copper washers. Unfortunately, I have never seen them before or on car itself as the area is coverd by black tar.

European cars like MB and Porsche have copper washer.

I too beleive that your leaks are coming from the seals. A quick check of on line forums indicates that this is fairly common. It is very rare for the injector to leak externally. Normally if an injector is leaking, the fuel goes into the combustion chamber. Before you go to take anything apart go to motorbooksguy.com and order up a shop manual. The books are printed in the UK for Uk and European vehicles. It will be the best 25 quid you spend. Not only will it tell you how to get things apart witout breaking anything really expensive, it will tell you how to bleed the pressure out of the system before you take it apart.

Common rail direct injection systems usually run between 20,000 and 26,000 psi. Pop the wrong part at the wrong time and it can get messy. In addition, the book will tell you if you need to spend anything extra in the way of special tools or if normal hand tools will do the job. Even if you have to spend another 50 or so on tools, it is cheaper than having this done at a dealer.

After you have spent a half hour with the manual and are ready to start work, plan on about 2 hours per injector as an average time if you are working fairly quickly.

I've seen several 4/5/6 cyl Mercs with this problem. It can be VERY difficult to extract the injectors, since the leaking cylinder products (not just diesel) form a 'tar' which glues the injector in place. After you've disconnected fuel and electrical parts (great care due to high pressure etc), you have to remove the two small screws which hold the injector clamp in place. You will probably need a form of slide-hammer which is screwed to the top of the injector, to get it out. Not a job for the feint-hearted!

The injector is a precision fit in a long bore, which may need to be reamed clean if you ever manage to get the injector out, then you have to clean the seating (reamer again) and fit new parts. The injectors themselves are quiter pricey even as service exchange parts.

Let us know how you progress if you're brave enough to start this daunting job.

It looks like you've done this before:) Yes, the injectors are, producing lots of tar - the first time I opened it I thought part of the plastic cover had melted over the injectors. The area is covered in tar, which I partly removed to, but removing it also increases the compression loss. At the moment, the tar helps to reduce the noise. I have never worked on a diesel engine before and wasn't sure how to get going. I have been told that the injector removal is hard but I thought have worked on everything from cars to planes and electronics, so it should not be that difficult in term of doing the job itself. However, not having experience of diesel technology, I was a bit reluctant to start the job. I am not sure about the precautions required to work on the pressurised injection system. I looked at a Haynes manual a while back to see if it was worth buying or not but unfortunately, it did not mention any references to common rail diesels. I have searched the web to see if there are any decent manual or videos of how to change the injectors or the seals. This engine is quite common as it is the C class, E class, V class and all the vans etc. I talked to Mercedes to find out whether this was something they could advise on – this problem doesn't occur according to them. They were not very helpful. I have been tempted to use liquid metal /epoxy compounds to seal the leaks or, make some sort of "over-washer" steel / ally plate. But that will mean damaging the head if injectors have to be replaced in the future. You obviously had a lot of experience of this, what would you suggest other than leave it alone? Are there any special tools required?

Thanks

I really wouldn't want to embark on your engine from the way you describe it, unless you have seen someone do the job before. Mine were not as severe as you describe, but I very nearly had to have a replacement cylinder-head, due to the dificulty of extracting the old injectors. This is a common situation. I recommend you try to find an independent MB specialist who knows the problems - such as Peter Hodge & Sons in Northampton. Good Luck!

Reluctantly I have arrived at the same conclusion only because if I get stuck or break something, which is my biggest concern, I would be stuck. ... Thank you ALL for your time & comments, goldendust

hi i had the same problem with mine,same model and year,it took me 9 hours to dig my injector out of the tar,i used a small screw driver and picks,you have to dig under the coller that holds the injector in, i used petrol to help loosen the tar,you have to just keep gently moving the injector from side to side once you have removed the tar,once the injector is out give it a good clean and make sure the seat in the injector hole is clean,this is a fair way down,again i used a small screw driver brake cleaner and an air line,get new copper washers and a new bolt,these bolts are very long,make sure the bolt hole is clean at the bottom,this is important.i ended up with blisters and very sore hands,but like you say mechanics arnt cheap.im female and i managed it,so be carefull and give it a go.best of luck

Well Done!

Your experience and comments have been very useful. This given me the confidence to have a go, as my fear was knowing what was under all the tar. I did look at the manual which did not show anything about this particular engine type and so I put the question out on the web.

Are there any precautions I need to take? What did you do about the pipes and wires when disconnecting? Did you bleed the system after & how ? or was it just simply reconnect all the pipes and start the engine? Its summer time and the weather is on my side so I'd like to have a go at doing it.

Thanks

i bought a manual for mine and it showed the wrong injector system,they dont screw in as they state they are held in with a bolted clamp

I am currently dealing with this on a c270 my dads mates car (happens to be a taxi ) am a tech for toyota, had a little trouble with injector number one as it was covered inthis carbon build up, but my main problem has been the bolts for the injector clamp the vehicle has been to a garage near me in east sussex and they have previousy removed the injectors re used the strech bolts and now seems like they have stripped the threads. tried using picks to clean and modified hoover also run a tap down but to no avail looks like i have to drill and re tapp for a larger bolt ???? hasanyone else suffered this problem ?

email me and i can help

I have this week experienced this problem on my merc cdi220 on a 2000 plate. The local garage snapped the injector hexi bolt in the head then had the pleasant experience of drilling it out for the next 4 hours, the thread then had to be re cut and a larger bolt fitted. The copper washer was replaced but it still chuffed past the injector once refitted this time however the car wouldnt start due to lack of pressure in the rail. The car was taken on a low loader to a specialist diesel garage and the prognosis was that 1 injector has to be replaced at a cost of £200 + vat and the another injector needs reseating. lay ahead ! He stated that once all refitted /pressure tetsted and reseated the rail will eventually build up the pressure and the car will restart. Morale of this story is goto an injector diesel specialist and dont try to save money by using a local garage.

Joe

I think you are right on that one, If the mechanic has not had the experience of this type of work he should say so, but most want to have a go as they are learning at your expense. I am an engineer and if I am not sure I leave it alone. It not that I not capable of doing the job but if I have not done it before then I would like somebody's opinion who has the experience of the job.

Sometimes its the little things that catch you out which may take a lot longer to fix and cost even more. However, I do not have confidence in mechanics any more after seeing some very shoddy work. My injectors only started leaking after I had a full service done which cost £600+ and had more problem after then before the service. It use to run beautifully before the service. This was one of the reason for wanting to do the job myself and so I put the question out to the forum to see if anyone had done it themselves. If I do the job then I will put it on the web so others can benefit from my experience and may serve as a reference point for those brave enough to try for themselves.

Hi

I have a 2001 Mercedes C220 CDI and i have had problems with all 4 of my injector seals. Not all at once though. Each seal went about 3 weeks after one another, which i am told is pretty common for Mercedes Diesel whcih has done around 100,000 miles.
Fortunately, I have a mechanic friend who simply purchased the seals for a few £ and replaced them with easy.
However, if the injector problem goes untreated for several weeks then the Tar will form and make it very difficult to extract the injector. (My first one did)
However, there is a special designed 'Mercedes Injector Remover' which you can buy for approximatley £100. This attaches to the top of the injector and you can yank it out without damaging the injector or the engine.
I have seen my friend fix all of my injector seals and have now completed one myself. I have no previous experience of Mechanics and assure you your can replace the seals yourself if you take everything slow and have a step by step guide.

Hi

Thanks for the comforting thoughts. The car finally has finally given up last week and I believe all four are leaking now. It is not drivable anymore and the tar build is such that you cannot see the injectors. The weather has now warmed up and I want to try to work on the car. I don't have a problem starting the job but I am afraid of starting the job and being able to finish. One of the obstacles is not knowing how to de-pressurise the system, as writer above says that the high pressures involved can get messy. If I knew how to do that, at least I could start the job.

I went to Mercedes and they did not want to know since their cars never have these problems. We have had mercs in the family since 1972, but these use to have less problems and dealers were more helpful and courteous. Now they just want your money and sell you a new car. Apologies for the rant... but it's their attitude.

I want to do this job myself just to stick two fingers at the dealer, that's how much they got to me.

I am therefore asking for help and have been trawling the web to find some guidance. I know I have to take extra care when cleaning the tar, which may take a day or two, but that does not worry me at all. I will be very grateful for any guidance you can offer and any precautions I need to take.

Hi

I am guest writer above.

Depressuring the system should not be an issue. The pressure is/has already released via the leaking seals. So you will be able to get to work straight away.

However, the tar build up will be your main issue. If you are unable to see the injectors, then it is possible other parts may have been damaged/affected by the tar. (This could also be cause of the cars failure).

A few days may be optomistic to clear the tar as the tar I expereinced after just a couple of weeks was pretty stuborn and it was almost like chipping away slate or stone.

However, assuming that you do remove enought tar and all parts are in working order, then this is what i did.

1) A flexible fuel injector pipe will run along the top of all 4 injectors. The pipe drops in to each injector and is held in place with a pin. Carefully remove the pins (make sure they doesnt 'Ping' off and out of sight). Once removed, lift the pipe off and out of the injectors. They also have rubber seals on the inside so you may need to praise them off with a screw driver.

A bit of fuel may leak out but this is nothing to worry about.

2) Remove the electrical connector on top of each injector also.

3) Each injector is connected to twisty metal pipe which has a 'nut' on each end. You need to completely loosen the one connected to the injector and slightly loosen the one on the other end. Once you have done this you should be able to spin the pipes around and out of the way of the injectors.

Again bit of fuel may leak out but this is nothing to worry about.

4) Below each injector head, there is a bolt, which goes through a V Shaped pin and straigth into the engine. The V Shaped pin should be hooked around the injector and holding it firmly in place. You need to remove the bolt and then the V Shaped Pin. This in theory leaves the injector free to be pulled up and out.....

(Due to the sever tar situation, you will probably not be able to pull it out easily. As mentioned in my previous post, you can buy a specially designed tool which will help you with this. It costs around £100 on Ebay and should have instructions with it)

* take extreme care when the hole is exposed. Anything small which is dropped down the hole will enter the cylinder block and have potentially disaterous effects. If you have removed the injector and you are working on something else, fill the hole with a tampon. It may sound strange i know, but it is soft so wont cause any damage and can easily be extracted and reinserted when required.

4) Once the injector has been removed, you need to get the copper seal from the bottom of the hole. (Again you can buy special tool to fetch this for £100+ but my mechanic friend uses a wire coat hanger, making a long handle and tiny hook at the end - does the job just fine!!)

5) Once you have the copper seal out, you need to make sure the hole is clear of any grit etc so that the new seal will have a flat and suitable base. If it doesn't then the seal wont work and leak will never be fixed. So you need to get in there with a torch and a something to clean it with. If you have some sort of vacuum cleaner with a very thin nozzle, then this would be ideal. Imagine a dentist's handheld spit sucksion thing. (Once again you can buy special tool to do this but my mechanic friend uses some kind of wooden stick with he uses to do a little bit of gentle straping and attaches celotape to the end to get anything which lies at the base. Simple, cheap and effective)

6) Once clean, give each injector itself a good scrub with some wire wool or a wire brush. This will remove any grit and ensure the seal is unaffected.

7) When the injector is clean, place the copper seal over the bottom of the injector, smearing it with some of the gel/grease which can be purchased with the new seals. Place the injector into the hole, making sure it falls to the same depth as it was before you removed it.

8) Simply reverse steps 1-4...
Place V Shap Pin around Injector. Screw in Bolt tightly. Bend around the metal pipes and afix nuts tightly, Reattach electrical connector, pop in the pipe into the top of the injector and clip on the pins.

9) Turn the ignition on. It may take a while for th engine to start as the pipes will need to refill with fuel. Give it a few attempts and it will eventually start.

I hope this helps, but please bare in mind this is the best i can explain it from my experience. You may have to take extra care or face extra difficulties when fixing yours.

http://www.uktools.com/ Search injector puller I think Bosch type.

Hello,

Does anyone know what the torque's are in relation to injectors for a Merc C220 CDi (W203)?

I have a blown seal and as I don't trust my MB garage not to try and rip me off with excuses around "it was a bit harder than we though so we had to remove the cylinder head blah, blah, blah" I have decided to do it myself. I have new seals, new bolts and the extractor kit so am good to go - just wanted to find out what torque's I need to be aware of. So any advice on this would be greatly appreciated.

Hi,

torque for new bolts is 7 Nm + 90 degrees (old version) or 7 Nm + 90 degrees + 90 degrees (new MB version). Take a pick.

New instructions came out because of numerous leaking seals, new risk is bolt snapping off or shredding threads.

Thanks for the response although I found the info out earlier and got the job done last weekend. I would like to say that the info that is provided in all of the threads relating to this issue was very very helpfull to me building up the courage to do it. I removed all four injectors and cleaned them up, cleared all the carbon off the cylinder head, replaced all the seals and torqued them up. Smell of fumes in the cabin has gone completely and I have checked a few times now under the plastic cowl and it all looks okay.

I paid £80 for th einjector removal tool and ~£20 for four seals and a tub of ceramic grease - so I reckon I saved myself a few bob.

Hello,

Thanks for responding although I found this out earlier and got the job done last weekend. However, I'd like to say that all of the info in this thread was very very helpful indeed and went a long ways to giving me the courage to do this myself. I am no mechanic but also could not afford another big bill! I bought an injector removal tool for £80 plus 4 x seals and a tub of ceramic grease for ~£20 so I reckon I saved a few bob. It was time consuming, freeing up the two injectors from the carbon, clearign the carbon itself and removing the old seals which had become stuck in the bottom of the holes - but after about 5-6 hours I had four cleaned up injectors and new seals greased and replaced into a carbon free cylinder head. Fumes into the cabin have gone and I've checked for leaks on a couple ocasisons and everything looks okay.

Doh!

The first update appeared not to have worked.....obviously just needed to leave it a little longer.

Hello I´m new and I´ve the same problem! I changed my injectors and now I want to know if it is necesary to program the "Mercedes Computer" to recognize the injectors. The motor is a 200CDI (Year2000). The mercedesguy told me that the configuration it is necessary, because they are 4 different types of injectors, but I don´t believe him.

Please help me! thanks from SPAIN! José