W211 hot start issues!?
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Results are in.
Injector on cylinder 6 is off the chart:
My next question would be if anyone recommends if I should buy a new injector or go for a refurb unit? Or is it worth having a look at the original one to see if the tip is blocked with carbon?
Thanks for all your help and suggestions.
Injector on cylinder 6 is off the chart:
My next question would be if anyone recommends if I should buy a new injector or go for a refurb unit? Or is it worth having a look at the original one to see if the tip is blocked with carbon?
Thanks for all your help and suggestions.
MrGreedy
MB Enthusiast
I have looked at injector replacement in a lot of detail before (not Merc). This is a quick summary of what I discovered on the pros and cons for new/recon/reman.
If you are planning to keep the car, buy new, and try and find the best price which might be for example a Bosch unit new, but likely not from Mercedes. Might also need coding. You will need to do some homework to find which part and what's involved if you want to minimise the cost.
If you are getting rid of the car, it is suggested recon/remanufactured. You need to find a company that can be trusted, as recon is replacing some seals, and remanufacturing is generally more thorough, but the reality is that none of these processes will return the injector to as-new condition. Therefore there is a school of thought that you are better off not even spending your money on a recon/reman unit, and just trying your luck on a second hand unit known to be working when removed. Much cheaper. A trusty garage to do this for you is likely worthwhile unless again, you are prepared to do the homework around which parts required and exactly how.
Hopefully someone will be along to advise on more detail of the specifics for the w211.
If you are planning to keep the car, buy new, and try and find the best price which might be for example a Bosch unit new, but likely not from Mercedes. Might also need coding. You will need to do some homework to find which part and what's involved if you want to minimise the cost.
If you are getting rid of the car, it is suggested recon/remanufactured. You need to find a company that can be trusted, as recon is replacing some seals, and remanufacturing is generally more thorough, but the reality is that none of these processes will return the injector to as-new condition. Therefore there is a school of thought that you are better off not even spending your money on a recon/reman unit, and just trying your luck on a second hand unit known to be working when removed. Much cheaper. A trusty garage to do this for you is likely worthwhile unless again, you are prepared to do the homework around which parts required and exactly how.
Hopefully someone will be along to advise on more detail of the specifics for the w211.
andym2
Active Member
It won't be the tip that's blocked, but the tiny valve in the middle of the injector. Google how piezo CDI injectors work and you'll see what I mean. I'd go with a new injector. They need coding ( you enter the code on the injector into Star) on some models... I changed an injector on my E220, it was about £250 from memory. You need to clean the seat and use a new stretch bolt. Getting the old injector out can be fun, particularly if there's any 'black death', but it wasn't too difficult.
Hi chaps, thanks for all your replies and advice. I've learnt a lot form this forum as always!
I bought a new copper washer and stretch bolt from Mercedes for around £5 and I got lucky and found someone selling a brand new in the box genuine Mercedes injector with identical part number and flow rating of the original one for £115! About the same price as a refurbished unit.
I removed the old injector easily as there was no black death, thoroughly cleaned the bore with isopropyl alcohol and shop towels, applied a thin layer of ceramic grease to the body of the injector and torqued down to 7NM + 2 90 degree turns.
The rail pressure whilst cranking is now around 300+ bar (was 170 bar), and it fires into life quicker than it has for years. Here's a video with the new injector installed and camshaft sensor disconnected.
It's worth nothing that the symptoms of a leaking injector were very similar to a bad CPS, so always worth checking. I'm wondering if this is also why the car struggled to get through the emissions test on it's last MOT when it's always been fine previously.
I bought a new copper washer and stretch bolt from Mercedes for around £5 and I got lucky and found someone selling a brand new in the box genuine Mercedes injector with identical part number and flow rating of the original one for £115! About the same price as a refurbished unit.
I removed the old injector easily as there was no black death, thoroughly cleaned the bore with isopropyl alcohol and shop towels, applied a thin layer of ceramic grease to the body of the injector and torqued down to 7NM + 2 90 degree turns.
The rail pressure whilst cranking is now around 300+ bar (was 170 bar), and it fires into life quicker than it has for years. Here's a video with the new injector installed and camshaft sensor disconnected.
It's worth nothing that the symptoms of a leaking injector were very similar to a bad CPS, so always worth checking. I'm wondering if this is also why the car struggled to get through the emissions test on it's last MOT when it's always been fine previously.
