Alans dad
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- Feb 12, 2019
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- Your Mercedes
- Vito 109cdi 2005 2.1 long
Hi. My Vito is up on ramps while I fix my alternator so I thought I would take the opportunity to search for the exhaust leak that has been coming into the cab the last few hundred miles. For those of you who are as naïve or ignorant as I am but still want to have a go your selves at finding and fixing this problem I will write down what I did and hope it helps you.
First I checked the exhaust pipe while I was under the van looking and listening for signs of a leak. There were none. Then I removed the big air filter housing on top of the engine. Then the fuel injector cover on the very top pf the engine. That revealed a lot of burnt on black deposit all over the fuel injectors and the surrounding area. I googled it and found it to be caused by a leaking injector seal. It is worryingly called Black Death. But don't fret. It is, according to YouTube videos, fairly straight forward to fix it. There were plenty of YouTube videos to educate me. I thought mine looked pretty severe compared to the first 3 videos I watched which had some slight staining. Mine was glossy black everywhere under that cover. I was relieved to find a fourth video of an engine that was totally encrusted with about a shoe box full of carbon crud and some gloopy oily sludge, all of which were fixed with some patience and perseverance.
These are the "simple" steps that I think are right and some questions (Please advise me if I am about to do it wrong) ....
1. Clean the mess up as well as you can so as not to let any crud fall in to the bolt holes and injector hole when you remove them. I saw someone using oven cleaner.
Q1. Is oven cleaner the best way to clean this carbon off?
2. Identify which injector(s) is leaking. It might be visible when you run the engine or if not visible then as one YouTuber did, he listened with a cheap stethoscope with the end pulled off. Putting the end of the rubber stethoscope tube up against the bottom of each injector and listening for the hissing leak.
Q2a. Is this the best way to find the leak if it is not visible?
Q2b. Should I just replace all four of the injector seals as a precaution?
3. Remove the wire clip on the top of the injector so you can ,remove little cap and tube thingy from the top of the injector. Unclip and remove electrical plug from the top of the injector,
4. Undo 14mm nut from fuel line at injector and loosen the 14mm bolt on the other end of the fuel line so that you can swivel the metal pipe out of the way.
5. Remove the star bolt that holds the injector clamp. Caution! This bolt is a "Stretch bolt". You can only use it one time so you need a new one to replace it. Also Don't let any dirt get inside this bolt hole as it will restrict the ability of the new bolt to do up tightly which will lead to more leaks. Stuff an easily removable cloth or paper bung into the hole to keep it clean.
6. Use an injector puller to remove the injector.
Q6. There seems to be lots of different types of pullers. I am not likely to do this job often enough or even ever again to warrant buying a great kit. Can someone advise me. Claw shaped puller with a slide hammer or something that you tighten up with a kind of tube that goes over the injector? Can they be hired? Anyone near Hendon NW London who would lend or rent me theirs?
7. Remove the copper seal from the inside of the hole the injector just came out of. This is what caused the leak and what you are replacing. I saw one person use a clean dowel rod with a tiny bit of grease on it to get the seal to stick on to it so he could lift it out. Another had an old screw diver with a tiny bend at the tip of it making a sort of burr which he hooked the seal out with.
8. Clean everything. the holes, the injectors, the top of the engine. Put in new seals. Replace injectors, Injector clamps. Put new clamp bolts into VERY CLEAN bolt holes. Tighten these with a torque wrench to 7 newton meters and then an extra 90 degree turn. Caution check that torque figure somewhere official. You don't want to over tighten and snap the bolt or under tighten and have another leak. I am just quoting someone else.
Put new little rubber seal rings on the little top cap and tube thingy (what is that called?) and replace the cap thingy. Plug in the little electrical plug. Reconnect the fuel line and tighten both the 14mm nuts.
Run engine and check for leaks. Replace cover and air filter. Have a cup of tea.
I have not started this job yet. I am about to do all of the above and hope that I will be doing it right. Please let me know anything I have missed or need to know. I understand that it must be kept clean so as not to block tiny holes in fuel injectors and I hear it might need lots of patience to remove the injectors as they jam into the engine and are glued in with the leaked carbon deposits.
First I checked the exhaust pipe while I was under the van looking and listening for signs of a leak. There were none. Then I removed the big air filter housing on top of the engine. Then the fuel injector cover on the very top pf the engine. That revealed a lot of burnt on black deposit all over the fuel injectors and the surrounding area. I googled it and found it to be caused by a leaking injector seal. It is worryingly called Black Death. But don't fret. It is, according to YouTube videos, fairly straight forward to fix it. There were plenty of YouTube videos to educate me. I thought mine looked pretty severe compared to the first 3 videos I watched which had some slight staining. Mine was glossy black everywhere under that cover. I was relieved to find a fourth video of an engine that was totally encrusted with about a shoe box full of carbon crud and some gloopy oily sludge, all of which were fixed with some patience and perseverance.
These are the "simple" steps that I think are right and some questions (Please advise me if I am about to do it wrong) ....
1. Clean the mess up as well as you can so as not to let any crud fall in to the bolt holes and injector hole when you remove them. I saw someone using oven cleaner.
Q1. Is oven cleaner the best way to clean this carbon off?
2. Identify which injector(s) is leaking. It might be visible when you run the engine or if not visible then as one YouTuber did, he listened with a cheap stethoscope with the end pulled off. Putting the end of the rubber stethoscope tube up against the bottom of each injector and listening for the hissing leak.
Q2a. Is this the best way to find the leak if it is not visible?
Q2b. Should I just replace all four of the injector seals as a precaution?
3. Remove the wire clip on the top of the injector so you can ,remove little cap and tube thingy from the top of the injector. Unclip and remove electrical plug from the top of the injector,
4. Undo 14mm nut from fuel line at injector and loosen the 14mm bolt on the other end of the fuel line so that you can swivel the metal pipe out of the way.
5. Remove the star bolt that holds the injector clamp. Caution! This bolt is a "Stretch bolt". You can only use it one time so you need a new one to replace it. Also Don't let any dirt get inside this bolt hole as it will restrict the ability of the new bolt to do up tightly which will lead to more leaks. Stuff an easily removable cloth or paper bung into the hole to keep it clean.
6. Use an injector puller to remove the injector.
Q6. There seems to be lots of different types of pullers. I am not likely to do this job often enough or even ever again to warrant buying a great kit. Can someone advise me. Claw shaped puller with a slide hammer or something that you tighten up with a kind of tube that goes over the injector? Can they be hired? Anyone near Hendon NW London who would lend or rent me theirs?
7. Remove the copper seal from the inside of the hole the injector just came out of. This is what caused the leak and what you are replacing. I saw one person use a clean dowel rod with a tiny bit of grease on it to get the seal to stick on to it so he could lift it out. Another had an old screw diver with a tiny bend at the tip of it making a sort of burr which he hooked the seal out with.
8. Clean everything. the holes, the injectors, the top of the engine. Put in new seals. Replace injectors, Injector clamps. Put new clamp bolts into VERY CLEAN bolt holes. Tighten these with a torque wrench to 7 newton meters and then an extra 90 degree turn. Caution check that torque figure somewhere official. You don't want to over tighten and snap the bolt or under tighten and have another leak. I am just quoting someone else.
Put new little rubber seal rings on the little top cap and tube thingy (what is that called?) and replace the cap thingy. Plug in the little electrical plug. Reconnect the fuel line and tighten both the 14mm nuts.
Run engine and check for leaks. Replace cover and air filter. Have a cup of tea.
I have not started this job yet. I am about to do all of the above and hope that I will be doing it right. Please let me know anything I have missed or need to know. I understand that it must be kept clean so as not to block tiny holes in fuel injectors and I hear it might need lots of patience to remove the injectors as they jam into the engine and are glued in with the leaked carbon deposits.
Last edited:
Slide hammer is a must. 
