[efair]

OK thanks for your advice.

 

[Dave2302]

So no recommendation to replace the chain guides?

Unlike others, MB Chain Guides are by and large very tough, inspect them and if cracked or seriously worn, sure, buy a Febi Bilstein Chain Kit or MB OE parts.

Check the Valve Timing before stripping, and only consider replacing Chain if it is retarded due to chain stretch. Tensioner yes replace it they have a hard life and you may not know the Oil Service history nor the quality of Oil that has been used in it over the years

Also, try not to replace Valve Seat inserts unless really necessary, I have had to get a Head Shop do them at times, and have had couple or 3 over the years that have dropped afterwards

 

[efair]

Unlike others, MB Chain Guides are by and large very tough, inspect them and if cracked or seriously worn, sure, buy a Febi Bilstein Chain Kit or MB OE parts.

Check the Valve Timing before stripping, and only consider replacing Chain if it is retarded due to chain stretch. Tensioner yes replace it they have a hard life and you may not know the Oil Service history nor the quality of Oil that has been used in it over the years

Also, try not to replace Valve Seat inserts unless really necessary, I have had to get a Head Shop do them at times, and have had couple or 3 over the years that have dropped afterwards

OK, I'll forgo the seat inserts then, and I'll check the timing today before ordering anything.

 

[Deplore]

It's fine to get the valves grinded, the actual valve, not the seat. They have to take out the valves anyway, so might as well?

 

[efair]

I got the compressor out today, tomorrow I'll shoot for loosening the exhaust and intake manifolds. On the intake side, do you need to remove the injectors, vaccum lines, hoses, etc from the manifold, or is it sufficient to just remove the bolts that secure it to the head and push it aside?

 

[Deplore]

Just remove the entire head with the intake manifold and exhaust manifold as a set, then you can unbolt those on the table at your leisure. Makes life so easy.

MB designed these to come off in sections, so as long as you disconnect everything, whole thing comes off as a set.

Unless you think fighting corroded exhaust nuts in tight quarters is fun....?

 

[efair]

I'll give that a try tomorrow, and I wonder why WIS doesn't follow this method, it sure sounds easier.

 

[Deplore]

Wis has to be written in a way if you're only looking to remove individual components and not complete sections. And then they say if you want to remove the head, then refer to page 12341 where intake manifold is removed, then page 123541 where exhaust manifold is removed, then go to page 14512 for cylinder head removal.

Smart guy does the whole thing in one go (space permitting) and gets it done faster.

Here's an exampe: BMW N55, replacing eccentric shaft and valvetronic motor, if you look up the official instructions, it has you removing the valve cover, timing cover, timing chain out, camshaft out before you can do eccentric shaft. Something like 12 hour labor. Shortcut? Remove valve cover, remove injector wells, unbolt the eccentric shaft from the side (not from the top as factory manual tells you) and you don't have to touch a damn thing. 3 hour max.

 

[efair]

I spent this morning trying to disconnect the exhaust header from the downpipe, one of the little rivnuts in the header came away, see photo, plus the rusty threads which I soaked three rimes, what a bother (of course I'm doing it alone, on my back). Had to buy a six point 13mm socket, 3/8 drive, because nothing else will fit around that useless bracket and O2 sensor...

 

[Deplore]

And that's the easy one. Still want to do the exhaust manifold nuts inside the car?

 

[efair]

And that's the easy one. Still want to do the exhaust manifold nuts inside the car?

No thanks! More details coming tomorrow or Friday.

 

[efair]

Sorry for the delay - rain, family matters, and the day job got in the way.

Can anybody advise me what thread size fits into the pin that secures the chain guide on the LHS? This is the pin that is pressed in/removed via slide hammer per WIS, so one can access the left-most screw that secures the head to the timing cover.

I've been through my entire bucket of screws and bolts to no avail.

 

[efair]

Answering my own question : M6 x something (see below). A 40mm long bolt of this size, plus a flange nut, and a 20mm long steel tube, got the job done.

Now if I can find a neighborhood kid to help me lift it out.

It seems like loosening the EGR fitting from the manifold, and unscrewing is steel line from its fixing points, made it easier.

 

[Deplore]

You sure it's M6x0.8? M111 is basically M104 that had 2 cylinders lopped off from the back. My timing guide pin was M6x1.0.

 

[efair]

I completely bungled this post... first, I measured imperial style instead of the simple thread pitch. Second, I see now the threads on my bolt are in sad shape. I've probably ruined the threads in the pin removing it.

 

[Dave2302]

It happens to the best of us, I'll bet that pin isn't very expensive from MB, likely the same pin in a lot of 4 Cylinders MB's and could even be same pin in others

 

[efair]

Nothing too compelling seen on the gasket, I'll check for warping next.

 

[Dave2302]

Well, that's not good news, looks like a little bit of damage on one fire ring but that would only account for one cylinder having low compression

If it were warped I'd have thought there would be obvious signs of blowing

Any sign of sticking valves ? Valve leakage ? .......................

If not ............................

 

[efair]

I see no signs of interference between the valves and pistons, I guess the time to check for sticking valves was before removing the head... 8(

The pistons are in the right place, and I did hear the car run briefly at purchase, albeit roughly, like on two cylinders... but long enough to rule out a bottom-end problem.

I'm gonna find a machine shop and roll the dice.

 

[Dave2302]

Put the head on level wooden blocks, combustion chambers facing upwards and fill them almost to head gasket face with petrol or brake cleaner etc, then observe if any is running out of the ports, which would indicate bad valve sealing.