How to replace timing belt tensioner and phasers

Welcome to 2CarPros.

Here are the directions for the chain tensioner:

2013 Mercedes Benz C 250 Sedan (204.047) L4-1.8L Turbo (271.860)
AR05.10-P-7800EVO Remove/Install Chain Tensioner
Vehicle Engine, Cooling and Exhaust Engine Timing Components Timing Chain Tensioner Service and Repair Removal and Replacement AR05.10-P-7800EVO Remove/Install Chain Tensioner
AR05.10-P-7800EVO REMOVE/INSTALL CHAIN TENSIONER
AR05.10-P-7800EVO Remove/Install Chain Tensioner
Engines 271.8 in Model 172, 204, 207, 212

All directions are in the attached pictures. Let me know if this helps.

Take care,
Joe

I knew it, stupid Benz placing it under the alternator. Thanks sir.

LOL. Anything to make things a bit more difficult. You are very welcome. Let me know if you have other questions.

Take care,
Joe

Any way for you to access some resources to find out how many bolts hold the alternator in place?

I got it, just need the new phasers torque spec and tensioner as well.

Welcome back:

I attached a picture of the alternator. It shows two. See picture 1. Also, picture 2 is what I believe you are looking for as far as torque.

Let me know if this helps or if you have other questions.

Take care,
Joe

How do i know if what i have is engine 271.8 or 271.9? as the torque specs you provided clearly show there are two different ones. Thanks

Welcome back:

From research, you should have the 271.8. This model had a turbo charger whereas the 271.9 had a supercharger.

Excellent, i thought so but drove me crazy the information was so vague. thanks for your help!

Happy to help. Keep me in the loop as to how everything turns out for you.

Take care,
Joe

having a problem with the camshafts, not able to place both phasers, when i put one on and put the chain on top of it and about to put the second the chain is too short to be able to let the phaser go on the camshaft, and even with the camshaft holder, they camshaft moves a little, and am not able to turn the camshaft to light up 100% with the phaser, i may end up just removing the whole chain and replacing it, is it easier if the whole chain replaced as well as the guides to give more room for the chain to be placed?

if i could find the right camshaft wrench which i can turn the camshaft just a bit i could do it, but can't find any size that fits exactly behind the sprocket.

Welcome back:

You need to release tension from the chain. Have you removed the tensioning rail? See pic 1

If you mean number 4 in the picture then yes, the plastic piece, i removed it.

Sorry i thought you meant the plastic piece between the sprockets, is it a bolt or what? Or you are talking about the rail itself? This is on the 271.8 benz c250 class?

Chain is loose on both ends if the sprockets now and the rail i can move it with my hand only held by the pin in the cover, so i don't think there is any more play to get loosened.

Chances are you are correct. And yes the rail. At this point, I feel it need removed and installed as a unit. Chances are it won't go unless it is done one step at a time. I was hoping you could get the play needed.

how are these chain guards removed, by removing the lower cover? :[
How can i ensure that both cams when lined up with the arrow that they are not 180 degrees off, is that possible here? they moved a bit when the chain jumped while i was turning the crank, but i put the T0 when i began the job.

Welcome back:

I attached two pictures below. Identify which one you are trying to remove. I hope it's the second because the first requires cylinder head removal.

Joe

I don't see the difference, these are for the 271.9 engines which are supercharged, mine is the 1.8l turbo 271.8.

Ya, neither are for my car because i see the chain on both pictures go over rather than under the plastic piece.

Mine looks something like this.

This is the 1.8T, correct? Also, is it a sedan, coupe, and are you located in the US?

Mine is 1.8 turbo 271.8 motor, pictures i think are for the 271.9 as it says in the picture, sedan, yes in the U.S.

I attached a pic below. Interestingly, I select the correct engine as seen below, but when I try to pull up guides and slide rail info, it takes me to the 271.9

Just to confirm, do I now have the correct pic attached? Also, I have to do a bit more research to find the directions. For some reason, it is jumping between engine designs for me.

Also, take a look at pic 2 for slide rail removal for either engine.

yes the picture is right, i seen the 271.8 and 271.9 many times in most guides, they are always grouped together because many parts and directions are similar, but the torque is different in some, and the way some of the pulleys are arranged are also different...

Welcome back:

Everything I have jumps to the other engine. I am going to ask one of the other techs here to see if he can provide suggestions. You may see a response from someone else.

Joe

Do you know if i remove the star bolts on top of the camshafts will that result in the camshaft coming out? I want to remove the top cover so i can put a wrench on the camshaft to rotate them a bit to align, this is the only way to do so.

Welcome back and sorry for the delay.

Yes, those bolts how the upper portion of the camshaft housing. I attached a pic below. All bolts locations will need removed.

Joe

What am asking is, if i remove them will the camshaft be loose, i just want to remove the cover so i can put a wrench and rotate the camshaft back to the mark.

Yes, they will be loose. You should be able to turn them without removing the cover.

I can't, there is no room anywhere to turn them, also how do i know whether the mark is on TDC, is the camshaft similar to the crankshaft where ot can be at a 180 degrees?

Welcome back:

No, they can not be off 180°

Finally got them all to line up, with regards to the star bolt in the picture which holds each sprocket to the head, there is a plastic piece in front if the bolt that is fragile i broke one and bought another whole bolt to replace it and while installing the other it also partially broke, do you know if those are important? See pictures with both the good one and the broken one, all i know is that the camshaft magnet sensor goes in front of the bolt after installing the timing chain cover, also once all in place and i want to turn the motor by hand to see how it is do i need to install the tensioner first?

Yes these parts need to be replaced. the system will not work unless you do and you must have the tensioner on before rotating the engine over.

Got it all together, the car overheats to about 246f and the fan is on high. i believe i need to bleed it? Can you get instructions on bleeding this car? The upper radiator hose isn't hard so i don't understand why she is overheating.

Can you see coolant flowing? There is no bleed instructions I can find. New thermostat? This guide can help:

https://www.2carpros.com/articles/engine-overheating-or-running-hot

Please run down this guide and report back.

it isn't flowing in the coolant reservoir, but i drove the car more than once before doing this job and was fine. you think all of a sudden this happened? possible? can you please find out for me what the coolant temperature range is on this car? Also, dang, the check engine light came on with p0017. geez

Kept cap off until warm with heater on, then capped it, turned car off came back an hour later expansion tank was empty filled again. did the same thing 4 times, now the temperature is stabilizing. thanks for all your help.

Good to hear. did the p0017 go away as well?