M104 C36 timing setup

[MihuAMG]

Hello guys! Hope everyone is doing great and enjoy their cars and not only.
Here im back again and hopefully some of you has,knows or can guide me in the right direction.
Long story short im in the process of head gasket job on my C36 and can’t find almost nowhere timing specs for this engine.
There was no place to mark anything when i took everything off because the timing was set as regular c280(probably by the shop who did head gasket again 4-5yrs ago).
Found some discussions on pelican forum but nothing solid enough to confirm that those are the AMG specs.Wondering if any of you have access to this kind of information or dealt at some point with something like this? Thank you!

 

[gerryvz]

Have you consulted the factory service manual? Timing should be taken care of using the factory procedures, as long as you can use the flywheel scale to align the crankshaft to the correct numbers, and pin the cams using a 4mm dowel/drill bit/etc.

If you look at my M104 Top-End Rebuild thread, you can see how this was done (I replaced the timing chain, as well as pulling the cylinder head and having it refurbished, and so forth.

Some additional resources here:

Mercedes Benz Model 124 - M104 Maintenance Manuals

https://www.500eboard.co/forums/threads/m104-m119-m120-om603-engine-service-manuals.18630/

 

[MihuAMG]

Hey Gerry,appreciate your reply,yes ive read your post very helpful and ill follow it once its ready to put it together.I have access to epc and specs for AMG is missing.It shows though the procedure for regular m104 and specify that not for AMG .Intake cam is different and a bit more aggressive that’s why the timing setup its slightly different.

 

[gerryvz]

Did you see the second link I posted above? It supposedly has AMG-specific information.

 

[MihuAMG]

I can’t access it,doesn’t open…seem locked or need some kind of approval

 

[gsxr]

I can’t access it,doesn’t open…seem locked or need some kind of approval

Try again, it should work now. Alternately use the link below. These are the factory manuals, you MUST use them while servicing any Mercedes engine.

Mercedes Benz Model 124 - M104 Maintenance Manuals

 

[MihuAMG]

Much appreciation! Will check it all out. Thank you

 

[MihuAMG]

What is your opinion about this chain guide?

 

[MihuAMG]

Hello Gerry.

In reference to the timing above,ive put everything back together to the specs,started the engine,it fires up right away exactly like before probably even better.Now giving the fact that the exhaust was flooded by coolant and also the age of the car,i decided to change the catalytic converter.While i was waiting to receive the new cat,I’ve driven the car pretty carefully and breaking in probably 100miles or so and never went dramatic on the throttle.

Now yesterday I’ve finally changed the cat,got on the highway with the hope of freeing some hp but contrary the car runs pretty poorly,no low torque at all and after i pass 3-4k rpm it starts to build up power all the way to the red however it feels like something it’s holding it,it wants to go ballistic but for some reason it doesn’t.No check engine light idles smooth.

Does timing can be at fault,giving all this?! 104 AMG has a specific (like diesel) rattle,and it feels that rattle changed like its a bit more pronounced at idling but goes away once you give it a bit of gas.What should i start with and double check ?!

 

[195910]

Check the Intake system valve system and leaks in the intake.

 

[gerryvz]

I would do two things:

1) Check the timing at the numbers gauge on the crankshaft, to make sure the timing is at the correct place. Rotate the crankshaft at least two revolutions to make sure everything is OK.

2) Pull codes from the computer to see what comes up. Reset all codes. Drive the car another 25-50 miles to see what comes back.

 

[MihuAMG]

Should there be any codes if timing is slightly off?
Ill pull valve cover off and check it again but when i put everything together, i rotated it more than twice ,camshaft marks were spot on with crank at 0T

 

[MihuAMG]

Check the Intake system valve system and leaks in the intake.

No hissing noise,new gaskets and vacuum hose…when you say valve system you’re referring at timing?

 

[195910]

No hissing noise,new gaskets and vacuum hose…when you say valve system you’re referring at timing?

If the markings are correct then I don't think its a timing issue. Its not a porsche! there is nothing to adjust.
I am referring to the M104 intake system resonance flap (Black box between the 1-3 and 4-6 cylinders intakes). If its stuck it will create idle and low-end power issues.

 

[JC220]

What is your opinion about this chain guide?

That guide is clearly spent! Change it.

Just for reference what timing system components did you replace here and were they genuine parts or what brands did you use?

Chain- IWIS etc
Tensioner
Guides
Sprockets- did they have any wear?

This is important as the chains do stretch and that combined with old worn guides could have the timing off by itself.

What made you go in there in the first instance? Was it to chase this issue?

 

[JC220]

Was the wiring harness replaced? I see prior threads of yours on the subject....

 

[MihuAMG]

That guide is clearly spent! Change it.

Just for reference what timing system components did you replace here and were they genuine parts or what brands did you use?

Chain- IWIS etc
Tensioner
Guides
Sprockets- did they have any wear?

This is important as the chains do stretch and that combined with old worn guides could have the timing off by itself.

What made you go in there in the first instance? Was it to chase this issue?

Everything was genuine except the aluminum guide which is discontinued,took it from BBR(claimed being a german genuine part).No wear shown in timing other than the guides.Blown head gasket was the reason .Harness was replaced at some point but not by me.

 

[MihuAMG]

If the markings are correct then I don't think its a timing issue. Its not a porsche! there is nothing to adjust.
I am referring to the M104 intake system resonance flap (Black box between the 1-3 and 4-6 cylinders intakes). If its stuck it will create idle and low-end power issues.

Oh,yes cleaned it and slightly lubed it,holds vacuum,no issues with it.

 

[JC220]

M104 AMG Engine - Timing set-up procedure - PeachParts Mercedes-Benz Forum

The timing set-up procedure for the M104 basic engine is shown in many threads and documents, for example, in the following link: http://www.ps2cho.net

www.peachparts.com

It appears this diagram is key:



Does that help and what are your timing marks set to at present? Did you know about this U mark?

I have a C36 AMG engine in my w124 but don't plan on opening it any time soon! But I would be verifying my original markings before I would ever dismantle it. I understand you have lost this opportunity on your engine. There is a you tube video on the C36 AMG engine timing. Appears flaky but may give a visual cross check for you now too.

 

[MihuAMG]

M104 AMG Engine - Timing set-up procedure - PeachParts Mercedes-Benz Forum

The timing set-up procedure for the M104 basic engine is shown in many threads and documents, for example, in the following link: http://www.ps2cho.net

www.peachparts.com

It appears this diagram is key:

View attachment 187658

Does that help and what are your timing marks set to at present? Did you know about this U mark?

I have a C36 AMG engine in my w124 but don't plan on opening it any time soon! But I would be verifying my original markings before I would ever dismantle it. I understand you have lost this opportunity on your engine. There is a you tube video on the C36 AMG engine timing. Appears flaky but may give a visual cross check for you now too.

Saw this doc,but don’t know what those arrows are pointing exactly and yes exhaust sprocket is in the U dowel.Also ive seen that video but nothing solid unfortunately.If you know for sure that no one stripped it then yeah pics need to be taken.

 

[gsxr]

Saw this doc,but don’t know what those arrows are pointing exactly and yes exhaust sprocket is in the U dowel.Also ive seen that video but nothing solid unfortunately.If you know for sure that no one stripped it then yeah pics need to be taken.

Read the entire thread at PeachParts if you haven't yet done so. It's explained pretty well in there.

 

[MihuAMG]

Just doubled checked the timing and appears to be spot on.Powered 12v on the advanced magnet and it clicks every time power it’s applied.Also found some silicone on the cam plunger,haven’t used much but probably I’ve touched it when i hooked the magnet (thinking that might not engaged properly because of that).Cleaned everything and waiting to give it a test later.

 

[gsxr]

Just doubled checked the timing and appears to be spot on...

I think that is spot off, not spot on.

Per the PeachParts thread, you cannot use the standard M104 procedure for setting the AMG cams. The AMG cams have their own special setup

 

[MihuAMG]

Read the entire thread at PeachParts if you haven't yet done so. It's explained pretty well in there.

I did,however everyone is just guessing,except the U dowel on the sprocket nothing concrete.The WIS specs say that the reg procedure does not apply on AMG engine,dealer also say that the exception is referring only to the U dowel on the exhaust sprocket.Haven’t tried to go wild and timing it the way the guys say(inlet 4mm mark below head and exhaust mark above head

 

[JC220]

Haven’t tried to go wild and timing it the way the guys say(inlet 4mm mark below head and exhaust mark above head

The statements are a bit conflicting, seems like above you haven't yet tried the settings people are saying works well?

Maybe that is the best thing to try next with the obvious caveat being to make sure you bar the engine over by hand by several revolutions before trying to start it up feeling for any signs of binding at all.

The alterative is to try and find a friendly C36 owner who will let you replace their cam gasket FOC and compare the cam timing visually at least!

 

[a777fan]

Just to clarify- you indicated the car was running as you would expect following the completion of your timing job and prior to installation of the new cat?

Only after installation of the new cat you started to see this behavior?

 

[MihuAMG]

Just to clarify- you indicated the car was running as you would expect following the completion of your timing job and prior to installation of the new cat?

Only after installation of the new cat you started to see this behavior?

Yes,but i also never went into the gas pedal more than 3-4k rpms prior to changing the cat,so kinda baby it.

 

[MihuAMG]

The statements are a bit conflicting, seems like above you haven't yet tried the settings people are saying works well?

Maybe that is the best thing to try next with the obvious caveat being to make sure you bar the engine over by hand by several revolutions before trying to start it up feeling for any signs of binding at all.

The alterative is to try and find a friendly C36 owner who will let you replace their cam gasket FOC and compare the cam timing visually at least!

There nothing official or documented about that setup,I have no idea where does it comes from. I lean to think that is a misinterpretation when in WIS is stated “not for AMG engines “ .All that is referring to the second dowel marked with letter “U” next to it,of the exhaust sprocket,when the regular 104s have only one dowel into the exhaust sprocket.
Yes that would be the best,finding a “virgin “ engine that wasn’t opened more than valve cover job or so

 

[gsxr]

When all else fails, check the opening / closing via dial gauge on the lifter (at 2mm valve stroke) while rotating the crank. This will tell you if you are within the allowed tolerance of 0-2° retard from spec:

AMG Inlet valve opens 28° ATDC
AMG Exhaust valve closes 16.5° BTDC

M119 shown in photo below, M104 is similar. If the intake opens at 28-30° ATDC and exhaust closes at 16-18° BTDC, you're all set.

If not, adjust as needed to get within those specs, via trial and error.

 

[MihuAMG]

I might found the issue,after scanning the engine for potential faults with C4 even though there’s no check engine light present,theres a fault for knock sensor 2 which obviously pulls timing and get into some sort of limp mode.It could be from spark plugs,since I went with iridium instead of copper but sensors are old and new ones fairly cheap so going to order everything and hopefully get it sorted out

 

[MihuAMG]

When all else fails, check the opening / closing via dial gauge on the lifter (at 2mm valve stroke) while rotating the crank. This will tell you if you are within the allowed tolerance of 0-2° retard from spec:

AMG Inlet valve opens 28° ATDC
AMG Exhaust valve closes 16.5° BTDC

M119 shown in photo below, M104 is similar. If the intake opens at 28-30° ATDC and exhaust closes at 16-18° BTDC, you're all set.

If not, adjust as needed to get within those specs, via trial and error.



View attachment 187666

Thanks much gsxr,probably best reliable way to make sure its spot ON.
So that’s actually the point (the values)when valves start to open and close

 

[TerryA]

@MihuAMG,
Most Mercedes perform better with the original OEM specified spark plugs. At least that’s how it is w/ the M119. I would suspect that the M104 AMG would be similar in that respect.

 

[Alphasud40]

Definitely fix the knock sensor fault. You are running on a base timing map which seriously compromises your HP. You will feel the ignition timing before a few degrees of cam timing.

 

[gerryvz]

Are the knock sensors still available from MB?

 

[MihuAMG]

Definitely fix the knock sensor fault. You are running on a base timing map which seriously compromises your HP. You will feel the ignition timing before a few degrees of cam timing.

Yes that’s how actually it kinda feels and sounds.as soon as im changing the spark plugs and knock sensors I’ll update with the results.

 

[MihuAMG]

Are the knock sensors still available from MB?

Yes

 

[gsxr]

Are the knock sensors still available from MB?

The M104 knock sensor assembly (003-153-78-28) for early engines is still available per MBCC and RevParts. This is a cable with integrated sensors. Pelican Parts says it's NLA but that may not be accurate.

MBCC shows the separate knock sensors 003-153-89-28 (cable not included) for late engines is NLA (link). However, there are Bosch aftermarket sensors available dirt cheap ($15 each!), and there may be some OE sensors still available from some vendors.

Depends which type you need...

 

[MihuAMG]

The M104 knock sensor assembly (003-153-78-28) for early engines is still available per MBCC and RevParts. This is a cable with integrated sensors. Pelican Parts says it's NLA but that may not be accurate.

MBCC shows the separate knock sensors 003-153-89-28 (cable not included) for late engines is NLA (link). However, there are Bosch aftermarket sensors available dirt cheap ($15 each!), and there may be some OE sensors still available from some vendors.

Depends which type you need...

View attachment 187840

Yes are the ones without cable,I ended up getting them quicker Bosch since dealer had to order them and you never know when they’re gonna come.

 

[MihuAMG]

UPDATE

”The BEE” is back on tracks runs solid&sounds good,got the low end torque all the way up to the red line ! Appreciate all your time and all the info provided.

 

[195910]

UPDATE

”The BEE” is back on tracks runs solid&sounds good,got the low end torque all the way up to the red line ! Appreciate all your time and all the info provided.

Nice to hear its running as it should, did you end up re adjusting the camshafts timing? or was it electronic?

 

[MihuAMG]

Nice to hear its running as it should, did you end up re adjusting the camshafts timing? or was it electronic?

It was pure electric condition,related to knock sensor/spark plugs.However it happened to ask someone who checked AMG specs degrees with a dial tool (since I don’t have a dial tool,yet,ordered one) and the 4mm holes behind the camshafts sprockets fell right above the head.

 

[yao500e]

@MihuAMG, glad you got your C36 running well and normal! C36 is a special car to me. In many ways, I like my C36 more than the w124 E500 even though its far far less market value.

I just had my '95 C36 M104 rebuilt by a master M104 tech. He was already familiar with the nuances and timing spec issues with the 3.6L AMG motor. My car runs a good or better than new with 118k miles or 195k km on the odometer.

Thank god the pistons, rings and rob bearings were all in good shape and just need to be thoroughly cleaned and restored. Pistons & Rings are near impossible to source and buy new these days! rod bearings are same as M104 3.2 motor thank god.

as time goes on, replacement parts for the C36 will become less and less. sadly.