C250 Sport - No oil change in 6 years and 50K miles.







Are you going to service the transmission when due? I’m not trying to rude or anything, just genuinely curious to know if your preventative maintenance views have changed or if you’re still following the “ignore it until there’s an issue” mentality.







I don’t think I’ve said it yet but excellent job on the repairs and work you’ve put into this.
The Best of Mercedes & AMG
I’ll have to replace a head gasket on my 2010 E250 CGI with M271.860 engine. It’s done 121K Kms.
I’m not planning to replace the chain as it was replaced 50K Kms ago.
I have a few questions, please.
1. Did you have to apply RTV Loctite SI 5900 when bolting on the End Cover (see pic)
2. How thick is the bead of RTV that you applied under the cam cradle?
3. So, if I use the black wedge I won’t have to remove the chain tensioner?



I’ll have to replace a head gasket on my 2010 E250 CGI with M271.860 engine. It’s done 121K Kms.
I’m not planning to replace the chain as it was replaced 50K Kms ago.
I have a few questions, please.
1. Did you have to apply RTV Loctite SI 5900 when bolting on the End Cover (see pic)
2. How thick is the bead of RTV that you applied under the cam cradle?
3. So, if I use the black wedge I won’t have to remove the chain tensioner?
1. Did you have to apply RTV Loctite SI 5900 when bolting on the End Cover (see pic) - yes
2. How thick is the bead of RTV that you applied under the cam cradle? Hard to describe and i did not take any pictures but it was just one continous bead same size as tube exit.
something like this video
3. So, if I use the black wedge I won’t have to remove the chain tensioner? Yes the black wedge compresses the tensioner so you do not have to remove it.
Last edited by azblk; Aug 17, 2022 at 12:00 PM.
2. How thick is the bead of RTV that you applied under the cam cradle? Hard to describe and i did not take any pictures but it was just one continous bead same size as tube exit.
something like this video https://www.youtube.com/watch?v=21CvanhKILA
3. So, if I use the black wedge I won’t have to remove the chain tensioner? Yes the black wedge compresses the tensioner so you do not have to remove it.
Many thanks for your response, azblk! Thanks for your effort.
I just found in WIS (not easy to navigate) where it says that the bead should be 2mm x 2mm, +/- 0.5mm.
I'm so sorry to bother you, but I have a couple more questions for you.
I think I feel comfortable with most tasks involved in changing the head gasket. The only area that I would stress about is removing / replacing fuel injectors and the high pressure fuel pump.
According to WIS, in order to remove the fuel pump, the crank needs to be rotated to a certain mark. Is this really necessary?
For fuel injectors, do they just come out with the fuel rail or is it a struggle to pull them out (as seen in this YouTube video)?
http://www.youtube.com/watch?v=nvNEU...el=Username_af
Also, do the white seals need to be replaced? (see below pic)
If yes, it seems that a special tool is needed? (as per pic below)
Many thanks!
Last edited by Milor; Aug 19, 2022 at 02:03 AM.



I just found in WIS (not easy to navigate) where it says that the bead should be 2mm x 2mm, +/- 0.5mm.
I'm so sorry to bother you, but I have a couple more questions for you.
I think I feel comfortable with most tasks involved in changing the head gasket. The only area that I would stress about is removing / replacing fuel injectors and the high pressure fuel pump.
According to WIS, in order to remove the fuel pump, the crank needs to be rotated to a certain mark. Is this really necessary?
For fuel injectors, do they just come out with the fuel rail or is it a struggle to pull them out (as seen in this YouTube video)?
http://www.youtube.com/watch?v=nvNEU...el=Username_af
Also, do the white seals need to be replaced? (see below pic)
If yes, it seems that a special tool is needed? (as per pic below)
Many thanks!



