1971 280SE (W108)

[Shadesh]

I bought a 1971 280SE (W108) with a straight six fuel injected engine with auto tranny about 2 years ago from a junk yard. Amazingly, the car is complete but had a blown head gasket. I am finally getting ready to replace the headgasket but really needed some thoughts / feedback from anyone who has done this before.

I would like to replace the headgasket, install new valve seals, new water pump and replace all the manifold gaskets.

I will post my questions to you in phases as I move along this process and would be very Greatful for any help or advise you could provide. I don't have a lot of experience, and am limited in funds but I am patient and willing to learn. I will complete rebuilding a Datsun 280Z (L28) engine in a few weeks and I think the Mercedes 280SE engine rebuild will be somewhat similar.

So that being said, here are my questions:

• Does anyone know if there is an online service manual that I can download?

• Are there other special tools other than the 10mm to take the head bolts out?

• Besides the headbolts, I have to set timing at TDC? , mark the cam sprocket where it aligns with the timing mark on the chain? ,

• Is there a trick that you use to wedge the timing chain?

• What else do I have to loosen besides the headbolts?

• Should I leave the intake manifold attached to the head and remove later?

Is there anything else I need to know as I get ready to pull the head out?

I am in Hawthorne, CA. If someone is nearby, feel free to contact me. Maybe you can come by and give me some advise. You don't have to get your hands dirty.
Thanks In Advance!

[Shadesh]

Anyone?

[wbain5280]

The fuel injection system must be kept clean. Be careful when removing the pipes, takes lots of pics. You should have done this in the Vintage forum, but here goes.

Does anyone know if there is an online service manual that I can download?



It's available from Mercedes on CD. You will need the 1959 - 1968 CD and the later one as well. The later manuals are supplements to the PONTON one.



Are there other special tools other than the 10mm to take the head bolts out?

You need to remove all the valve components first. Screw down the valve adjusters and remove the finger followers and the small springs, bag and ID them. Do not mix and match.


Besides the headbolts, I have to set timing at TDC? , mark the cam sprocket where it aligns with the timing mark on the chain? ,

Replace the timing chain. Grind off one link and attach the new chain to the end. Rotate the engine and feed the new chin in. Watch those small circlips don't fall down the chain hosing, Stuff rags in there.


Is there a trick that you use to wedge the timing chain?

Do not wedge the timing chain. You would do well to replace the chain and guides. You will have to remove the tensioner as well. Check the sprockets for wear by looking at the tips. If they are sharp and pointed, replace them. If the ends are squared off, it's OK. Replacement guides are plastic. They are held in with pins. Check one of my other posts:

420SEL: Chain Guides Replaced

220S: 220S M180 Engine Work


What else do I have to loosen besides the headbolts?

The throttle linkage needs to be removes. Do not make any adjustments to either the throttle stop or the injection pump stop. Use a small open ended wrench to pop the socket off the ball joint.


Should I leave the intake manifold attached to the head and remove later?


Remove the intake and exhaust manifold. Use new copper nuts. Watch those injection pipes. Consider sending the injectors out to be cleaned. They operate at approx 250psi.

Check this forum, same engine: http://www.sl113.org/forums/

[Shadesh]

Warren, Thank You for your input. Its appreciated. ..and I will get a hold of those cds too..

I will update as I move along this process..

Shadesh

[Shadesh]

I found someone with a complete engine (with a good head). How do I know that the head will be compatible with mine? I remember someone mentioning that there are two different types for the 280SE.
I saw the below chart but am trying to understand what it means. Should the head that I buy also be stamped 130 016 08 01 280SE/A??


The engine stamp on my car is 130 980 12 053213
The head stamp on my car is 130 016 08 01 280SE/A
The vin # is 108 018 12 071273.
1971 280SE with inline six fuel injected.

[Shadesh]

anyone?

[JeffreyNMemphis]

That chart is not going to help you. Your car is not on it.

Call the Mercedes Benz Classic Center and ask them which head you need.

[JMela]

http://www.mbusa.com/mercedes/#/onlymbMenu/classicCenter/

1-866-MB-CLASSIC (1-866-622-5277)
Local: 949-598-4850
Email: classicparts@mbusa.com

[Shadesh]

Thanks.!

[cth350]

Ideally, you want the identical casting number stamped on the head.

Under the casting number is an "e" and a ratio (like 8.5 or 9.0). You would prefer a larger number (higher compression).

Lastly, there was a head gasket change at some point for the M130E motors. The EPC will tell you what the engine number cut-off is.

Having said that, you're head is NG? Any head you acquire will need to get new guides. You can't avoid replacing them. Most heads will also need to be milled flat. You would much prefer to do that to only one surface, not both.

Thx -CTH

[Shadesh]

Originally Posted by cth350

Ideally, you want the identical casting number stamped on the head.

Under the casting number is an "e" and a ratio (like 8.5 or 9.0). You would prefer a larger number (higher compression).

Lastly, there was a head gasket change at some point for the M130E motors. The EPC will tell you what the engine number cut-off is.

Having said that, you're head is NG? Any head you acquire will need to get new guides. You can't avoid replacing them. Most heads will also need to be milled flat. You would much prefer to do that to only one surface, not both.

Thx -CTH

Thank You, Thank You, You answered my question. Now I know what to look for. Basicly, the head that I am buying should have the same casting number stamped as mine which would be 130 016 08 01 280 SE/A. .. and look for a higher ratio.

Correct me if my understand is wrong.

[Shadesh]

Can someone tell me the Cylinder Head Bolt torque specs / sequence for my 1971 280SE. Its a M130 engine (straight six injected).

Should the bolts be torqued when the engine is hot / warm as well?

[Shadesh]

Originally Posted by Shadesh

Can someone tell me the Cylinder Head Bolt torque specs / sequence for my 1971 280SE. Its a M130 engine (straight six injected).

Should the bolts be torqued when the engine is hot / warm as well?

Anyone?

[Joe Schmoe]

280 SE/8 starting 1968, rev July 1973.

Torque steps.
with engine cold 1) 4 mkp 2) 7 mkp 3) 10 mkp
with 80C water temp 4) 11 mkp

All above are accompanied by note 1: replace 10K bolts by 12K bolts.


Final torques.
Engine Cold 10 mkp
Engine Warm 11 mkp

Sequence:

FRONT| 12 8 4 2 6 10 14 |REAR
FRONT| 11 7 3 1 5 9 13 |REAR