M104 AMG Engine - Timing set-up procedure
 

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/downloads/MB%20CD/W124/w124CD1/Program/Engine/104/05-2230.pdf

As noted, in the above link, the procedure for the AMG version of this engine is different.

In error, I set my engine as per the basic procedure above. My AMG engine runs fine above 1000RPM, but the idle is lumpy like a rottweiler dog pulling at a chain at idle.

Relevant differences I have noted during research indicate:

1. Different inlet cam and valve lift.
2. Different valve overlap.
3. Inlet valve opens 28 deg ATDC on AMG (34 deg ATDC C280).
4. Exhaust valve closes 16.5 deg BTDC AMG (14 deg BTDC C280).
5. Variable valve timing is 26 deg AMG (20 deg C280).

My question is...Does anyone know, or have a link to the procedure for setting the camshaft valve and timing chain for the M104 AMG engine?

The cam size shouldn't affect timing unless they change the LCA. That said, did you make sure the cam was in the retarded position when you put the chain on?

Yes I did ensure that I retarded the cam adjuster.

The cams are set on the 280 version as per the dowel holes drilled into the back of the cam gear sprocket wheels. However, the AMG valve openings are advanced by 6 deg for the inlet and 2.5 deg for the exhaust.

That advance could be achieved by a new cam profile for the inlet camshaft (it is an AMG specific cam part number). It could also be achieved by advancing the sprocket gear one or two teeth.

But how do they achieve 2.5 deg advance for the exhaust for the exhaust cam which is identical to the 280 engine? Could that be achieved by the higher compression (shaved) head alone, or shaved head and advance one tooth?

Its done as follows
Attachment 78988

Thanks for that jem of information Jay. That makes a lot of sense to advance the cam shaft by moving the dowel locating pin. That helps me a lot in making sense of what I saw earlier today.

I pulled the valve cover a few hours ago and check the marks and timing of the valves. The exhaust is pretty much spot on. But the intake valves are opening about 25 deg early...oh! oh!...looks like I must have assembled the timing with the camshaft adjuster in the fully advanced setting as opposed to the fully retarded position.

Photo shows inlet sprocket 4mm timing hole advanced due to AMG modified dowel location (3.5mm drill bit inserted after sprocket positioned to illustrate new AMG position).

Question: Can anyone confirm that if I set-up the timing for my M104 AMG as illustrated in the photos, but, correct the VVT to full retard, that this will be the correct procedure for the M104 AMG?

http://img697.imageshack.us/img697/3579/032sp.th.jpg

General view.

http://img707.imageshack.us/img707/8461/031dt.th.jpg

Exhaust sprocket 4mm timing hole spot on.

http://img707.imageshack.us/img707/8452/030xs.th.jpg

Settings were at TDC.

http://img697.imageshack.us/img697/9048/023ya.th.jpg

I pulled the timing cover today and I found everything on the intake side was normal...I had reinstalled the VVT cam adjuster and set it correctly in the fully retarded position.

However, I found out how the AMG factory achieved the change in timing (from the C280 engine) on the exhaust cam. AMG reworked the cam sprocket. They elongated the holes for the three retention bolts and also drilled a new locating dowel hole.

If you have two holes available, you just know that someone is going to use the wrong hole. Yep, that's what happened...I should have use the new hole marked with a "U".

This is what I found (exhaust cam sprocket)...

http://img683.imageshack.us/img683/6433/033hr.th.jpg

I still don't know the basic timing setup for AMG M104 and how it varies from the C280 M104 setup. Any takers on this one?

At the moment I am turning the crankshaft over after trying different chain sprocket positions and trying by trial and error to achieve the AMG spec settings of:

1. Inlet valve opens 28 deg after TDC; and
2. Exhaust valve closes 16.5 deg before TDC.

I have the exhaust setting spot on.

But the 4mm drilled hole on the inlet sprocket will be way off when I set the cam to achieve the 28 deg event.

Appreciate any input guys!

I really should acknowledge JayRash for his link on the exhaust valve timing as that was the precise source of my timing problem there (assembled using the wrong dowel hole). I didn't quite understand or appreciate the significance of the information in the link on the first read. Thanks JayRash!

There must be some guru here that knows or has access to the timing setup procedure for the M104 AMG engine?

I really would appreciate any help or advice or direction from any kind soul on this situation before I button it up and take my chances.

Thnz Oz,
ill try and pry that info from my mechanin on monday afternoon, but i wont promise u much for he is a bit tough to deal with in this respect.

Thanks JayRash, any information would be much appreciated. I have worn my fingers out searching Google and the Tech books I have access to. I am just thrashing around in the dark at the moment!

droped M.B.DOC a PM he might have that info.

JAY

ALL M104's set the basic cam timing that way.

If you remove the valve cover & rotate thae engine ONLY clock-wise to TDC, both pins should go into the camshafts w/o moving anything else!

Hi M.B.DOC,

Many thanks for your personal attention and expertise!

As I understand the AMG engine, the exhaust cam is stock standard with the C280. But AMG has slotted the three attachment bolt holes of the exhaust cam drive sprocket to advance the exhaust timing about 5 deg. They also drilled an additional dowel locating hole which is marked with a "U". I think this causes the timing mark to be about 3-6 mm above the top of the head with the 4 mm drill inserted.

AMG also installed an AMG-unique reprofiled inlet valve cam. Also they changed the variable valve timing (VVT). So exactly where the 4 mm dowel should be on the timing setup for inlet valve cam for the AMG is a mystery to me. I can present cases to support the dowel hole to be above the head or below the head for line-up of the 4mm drill bit.

If you can shed any light on this dilemma, I would be extremely appreciative!

OZ,
Was the exhaust cam advanced or retaded 5deg?

Hi JayRash,

The exhaust cam sprocket has a slotted modification for the attachment bolts. With the cam set on the dowel AMG modified hole marked "U", it is rotated clockwise compared to standard.

So I would say it is advanced from standard?

http://img683.imageshack.us/img683/6433/033hr.th.jpg

ok since it rotated clock wise, come assembly time dont u rest the sprocket to the correct mark? Wouldnt that mean the cam now is retarded to get the correct set up at TDC?
Just asking for its been some 11 years since i played around with cam gears.

If you set the sprocket to the "correct" mark, it would be retarded and defeat the purpose that AMG mofified the sprocket to advance the cam.

Also it would move the sprocket half of one tooth (5 deg). Each tooth (36 teeth) is equal to 10 deg. Therefore the "correct" mark is NOT achievable.

More to the point perhaps, the following link from the Mercedes Worksheet says NOT to use the marks at the head level for AMG engine.

http://www.peachparts.com/shopforum/newreply.php?do=newreply&p=2446504&dr_log=-1&linkout=http%3A//www.ps2cho.net/downloads/MB%2520CD/W124/w124CD1/Program/Engine/104/05-2230.pdf

Timing Setup Procedure for the 1996 C36
 

OK, after much research, I have come up with the following setup procedure. My car is running beautifully with this setting. So I believe it is perfect...or pretty damn close!

Set the crankshaft angle to TDC with cylinder on the compression stroke. Then:

1. There are two dowel guide holes on the exhaust sprocket of the 1996 AMG M104 engine.
2. Use the dowel hole that is marked with a "U" (modified by AMG to provide 2.5 deg advance on the exhaust valves).
3. Set the 4 mm guide hole approximately 4-6 mm above the level of the head (as opposed to level with the head on the C280 M104 engine).
4. Set the inlet cam sprocket with the 4 mm guide hole about 2-4 mm below level with the head (as opposed to level with the head on the C280 M104 engine).

Exhaust cam sprocket.

http://img709.imageshack.us/img709/7872/043fy.th.jpg

Exhaust cam 4 mm guide hole setting at TDC.

http://img709.imageshack.us/img709/7726/032uj.th.jpg

http://img97.imageshack.us/img97/8083/036vmp.th.jpg

http://img97.imageshack.us/img97/9445/033vz.th.jpg

Inlet cam 4 mm guide hole setting at TDC.

http://img191.imageshack.us/img191/8153/041nlb.th.jpg

http://img718.imageshack.us/img718/3869/038ga.th.jpg

The engine still surges about +/-150 RPM at idle...and it is obviously not yet perfect...

I even emailed AMG, but nothing useful in reply as yet.

Any gurus out here that may be able to help?

Ok I blew the head gasket on my 36 AMG due to a failed water pump, this is the second gasket in 6 months :S


Any way come assembly time my mechanic set the timing as follows:
1- the exhaust Sprocket set using the U dwell hole.
2- Intake variable set to retard.
3- The 4mm holes with the timing chain firm are slightly over the head level on the intake side and slightly lower than the head on the exhaust cam.

the car idles steady and fine. now as its the engine should be running slight retard.

ill confirm abt the power, top end, low end, idle and driving feel in the coming few days. ill also race several cars i had race before to see if it was setup like before or not, and if its better or worse.

BTW an engine with cams retarded should idle steady, advanced should feel lumpy like its on cams, i for one have no idea how the 36 AMG should idle but slight retard is useful on the AMG since it has enough torque low down, so top end will help me pull gr8 from 5kRPM to 7K shift point.

any input from u guys would be gr8.

Hello JayRash,

Thank you very much for your post and information. It makes sense to me as I have come to the conclusion that my uneven idle is caused by having set my inlet and exhaust too far advanced.

Let us know if you decide to vary your setting after further tests.

Cheers,
Oz

OZ
i am glad to help in any way and i sure will keep u posted
but i kinda proved my point regarding the first post on this page on the top.

Any way how is the low down pull on ur car and how is the car on the top end, where does it start to trail?

I will post how mine is on my settings.

Strangely enough, the low down pull is very good and seems to improve above about 3000 RPM and then goes very strongly all the way to 6300 RPM. I will live with the uneven idle for a few more weeks then get amongst it to reset the timing as you suggested.

when cams are advanced low down pull wil be gr8 rather impressive. I wanna try ur settings in a month or so
then ill see which i would keep

just wanted to ask have you changed the injector seals and cleaned the throttle actuator?

Hello taint,

Yes I had the injectors serviced, and new seals. Also the throttle body was completely cleaned.

I have some information on timing that indicates I am still a bit off on my settings and I will post that when I get around to resetting the timing.

OZ
do u want to try the way i set my cams? My car is running gr8 thou i also have a tiny tiny bit of hunting when oil is really hot.

Hello JayRash,

I am going to set my timing the same as yours (as you previously suggested), unless you have found an even better setting.

no man i am still on the same setting, i think its the original settings from AMG its just that this is the second head gasket in a row so the head has been slightly shaved for a clean fit. This will have me running slight retard over any stock setting but it shouldn't be much to make any difference

Does anyone know if the timing is changed as well on a M104.980 BRABUS 3.6-24 engine as I am about to get the last finger slip on my engine refreshment?

I can see that I don´t have dobbel dowel pin holes at least, but I know that brabus fitted the engine with a modified inlet cam just as AMG did and the other cam was as original like the AMG.

But my dowl marks fit right on when I turn the cams and the cam advancer system like it should, they also changed the compresion to 10.5:1 from 10:1

The .98 based 3.6 may be different than the AMG .94 based engine. If you could read me the cam codes we can let you know the differences.

Where do I read the cam codes`?

Well, ? :confused:

The engine is started up now but the timing is set to standart and the advancer sprocket has been turned clockwice and the cam counter clock wice and the the 2 dowel holes fittet with 4mm pins and the engine stands on TDC.

I guess thats the right setting, it drives with one hell of a low down power grunt :D should be close to 300 Nm at 1500 Nm. so that feels right.
just fill in some 99 high Octane V-Power :P

BRABUS camshaft B5 and B6 kit informations.
 

This is what follows with the brabus Performance camshaft kit.
That is quite some modifications for just a performance cam.

What do you make of that :)
Includes a controlbox for air control as well.

The fact that my car drives with the B6 kit as a part of the 3.6-24 engine enlargement, I can now see that my cam adjustment must be right, no new dowel holes or anything else to be confused or mistaken about ;)

An old thread, but...

Even though I had the injectors serviced, we finally discovered that the repairer had failed to put new seals on them. The old seals had partially failed on the inside surfaces (not visible unless the seals are removed) and caused air leakage into the mixture formation.

taint was correct in his diagnosis!

So is every one's C36 engines now runnig well??

I'm going to repuild an C36 engine and the timing chain was of when I bought it.

So is this the correct way:
1- the exhaust Sprocket set using the U dwell hole.
2- Intake variable set to retard.
3- The 4mm holes with the timing chain firm are slightly over the head level on the intake side and slightly lower than the head on the exhaust cam.

Thanks

Wow this is an old thread.
As far as I can remember the procedure above is what I set for the timing.
My car is still running incredibly strong!
The idle problem was purely leaking injector seals.

Good luck and enjoy the torque and anger of the AMG M104!

I'm in the process of refreshing a 3.6 also. I didn't start to disassemble it yet but I have to valve cover off so I will post some pics of where the holes are positioned on the cam sprockets.


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This is how I did it on my C36 as well. Seems to be running well.

M104 AMG Engine - Timing set-up procedure
 

I've checked my engine and it's set to factory setting like any other M104.
But I got this engine from pick-n-pull so I don't know how it ran before. https://uploads.tapatalk-cdn.com/201...cea909df8b.jpg
https://uploads.tapatalk-cdn.com/201...41634ecfb0.jpg


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You guys were right AMG timing is set different from stock M104
https://uploads.tapatalk-cdn.com/201...29040fe6e7.jpg


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Hi guys , i have 3.4 AMG and i have no idea how to set up the timing right. TDC on my 1st cylinder is on mark 25 degrees advance on the pulley . the tdc on the crankshaft sensor is matching the piston tdc. So either my pulley is misaligned somehow (the harmonic balancer is in great condition) or AMG engine should be synchronised with the camshafts (4mm holes) at 25 degrees advance on the pulley . then at 0T on the pulley the 4 mm holes will be as you wrote - intake 4-5 mm under head edge and exaust 4-5 mm over the head edge!if this is not correct than i have no idea what to do , my car deffinatelly has no power at the regular 104 settings !

Is there anyone that can confirm they have set the camshaft with 100% success or what?
//

Hi , i found a man in germany with 3.4 in stock condition ! I wait for an info from him about the timing because he is about to change his head gasket! I will share :-)


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I have 2 3.6 engines, both have had the timing set to factory m104 standards. I've rebuilt one of them set the timing the same way and it works perfectly. I believe most of these issues come from not setting the cam adjuster correctly.
So make sure to follow the procedures for setting the cam adjuster correctly and it will be all good.
My 3.6 have plenty of power, up to redline and I love it!


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So basically you put the 4 mm drill in the backside of both the inlet and exhaust sprocket? and set the crankshaft in tdc? or OT as it says on my crankshaft pulley.

Was the exhaust sprocket using the U marked pin or the one without the U?

That's correct, set it with the holes lined up with the surface of the head and crank at tdc.
I don't know what you mean by U marked pin. There's only one hole on each can sprocket thats 4mm oriented the same way on the intake and exhaust side.
I'll try to post a pic if I can.

Intake
https://uploads.tapatalk-cdn.com/201...cdb3570d7f.jpg

Exhaust
https://uploads.tapatalk-cdn.com/201...f0091245ac.jpg


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Ok but does the Engine runs smooth on idle and when you rev it? Im having the c36 amg 3,6 litre Engine. My exhaust camsprocket has an U mark on the side where the sprocket is bolted to the camshaft attached, the side that facing towards the radiator so there is possible to mount the camsprocket to the camshaft on 2 possible ways.

So you did set it to the standard setting like all the m104? do you know from which year the Engines are from?
//

Have you tryed to adjust the timing this other way??
1- the exhaust Sprocket set using the U dwell hole.
2- Intake variable set to retard.
3- The 4mm holes with the timing chain firm are slightly over the head level on the intake side and slightly lower than the head on the exhaust cam.


Maybe you could test this :)

I don't know how other 3.6's run because this is the first one I've driven. I know how fast a 3.2 is and this is definitely faster they both idle smooth. Timing is set same as a standard m104. Still running the stock E320 ECU.I have a '95 on the stand and a '97 in the wagon.

Idle and acceleration

https://youtu.be/75K37CNJC0g

I'll check my cam sprocket later but I'm pretty sure mine only bolted up one way.