W108 280SE - M130 Cracked Header

[Palolo]

Not sure how common this is, or what the cause is, but as I was poking around in the engine bay, I noticed some spider-cracks in the rear exhaust manifold.

Any idea if there's something that caused this, or was it just a case of age, stress and heat?

Maybe it is related to my "doesn't re-start when hot" issue...

[cth350]

cast iron doesn't like certain kinds of stress (like thermal cycling rapidly; hitting it with a hammer). You have to replace that manifold. Fresh air gets in where it doesn't belong and the result is higher than expected temps around your valves.

-CTH

[Palolo]

Thanks.

A forum member has a set that will soon be on its way to me, by coincidence, then I spotted the cracks.

[Palolo]

I got the exhaust manifolds after a brief stop at the coaters, now to figure out how to get them installed. Looks like a lot of disassembly before I get to the exhaust manifolds.

I have a new gasket on its way in, and the copper nuts are available locally.

Are there any other "should replace" parts that I should pick up before removing the old cracked manifolds?

Before and after pics are below.

[bwostosh]

drop the exhaust system from the rear mount and pull the intake manifold with the exhaust manifolds, and clean it's interior and throttle completely, also adjust the valves while it is off. (Easy access). Maybe replace the thermostat while you are there and the short hose from water pump housing to thermostat housing is a must do. If you have the A/C mount this gets to be quite a task. Well, since you can see the motor mount, replace it while convenient, check those sub-frame mounts too, and tighten the cap nuts on the exposed upper A-arm.

Get 2 new seal rings between the cast manifold and the head pipes, 6 new connecting bolts and nuts too.

Re-torque all these after initial start and warm-up.

[JPMOSE]

Removing the bolts has to be done with a lot of TLC! I would research this to death, in order to gain the most tips. Last thing you want is a frozen bolt snapping in the engine. Obviously, soaking them at length with PB Blaster (my favorite) is a start. I haven't done this task personally, but I remember a shop using a blow torch on my 1969 Lincoln Continental..but that was a cast iron engine.

Best of luck! I will follow this thread out of interest.

[Palolo]

Thanks Brian and JP.

I think I have another week or so of parts-gathering to do before I tackle this one.

I just did the subframe mounts (a brake pad job turned in to subframe mounts) and thermostat.

Will look for the other parts mentioned and get them here before I dig in to pulling the intake and exhaust.

Cheers,

Pat

PS: I do have the York AC, but it isn't charged, so I am considering pulling it off until I am ready to tackle AC.

[wbain5280]

Get a Sanden compressor.