OK, here's the situation: 1991 300E with 78K miles on it, running perfectly except: I had a hose split open, the one between the motor and the heater core on the driver's side. I never came close to overheating, and I thought it would be a simple fix. Turns out the split hose was just a symptom of the real problem, a blown head gasket and oil in the coolant.

So, being a mechanical engineer, and someone who's turned wrenches on just about everything for the last 25 years, I plan on doing all this work myself, I just need a good plan of attack, one that will be cost effective too.

For right now, I am just planning on R&R for the head gasket and valve seals. So my parts are going to be a hose, a valve stem seal kit, a head gasket kit, valve cover gasket, the new bolts and washers, and what else?? camshaft seal?? Anything else?

I don't want to do the valves now for these reasons: The car's history is one of a immaculate maintenance record, with frequent oil changes and the majority of the driving is commuting on the highway to work (14 miles one way). The car runs like an absolute top. Of course I'll do a compression test before I dissamble it (need a baseline), but I don't anticipate any surprises from that. Also, MB changed the material of the valves / guides in 1990, so my 91 is supposed to have longer lasting guides.

For similar reasons I don't want to do the timing chain now either. I've still got 22K miles until 100K.

Of course this depends on what my inspections find when I take it apart.

My other concern is flushing the oil out. I plan on flushing as best as I can or have patience for after reassembling the motor with this bit of work. Before summer (April or May), I was planning on replacing the radiator. I'm going to expand the scope of that job to include more flushing, replacing the expansion tank and all the other hoses and thermostat at that time. That way I can be more certain that I've gotton all the oil out before I put the new radiator, expansion tank, and hoses on.

The valves and timing chain I'll defer maintenance on until I reach 100K - 120K miles, just raise my awareness to the state of things, like perform a compression test every 7 - 10K miles from now until then.

Are there any holes in my plan? All opinions are gladly welcomed on this.

I'm figuring what, 6 - 8 hours time to R&R the head gasket, with inspections. Is that fair for a very experienced amatuer wrench?

Also, how much does the head weigh, both with and without the manifolds attached?

And finally, Larry Bible, you described leaving the intake manifold in place in the car to remove the head, describing that you had to climb up from underneith the car for some bolts. Was that on a M103 motor? (I don't see what bolts I can't reach from up top.) Could you please describe your process in more detail? Thanks

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On the plains of hesitation bleach the bones of countless millions who at the dawn of victory, sat down to wait, and waiting -- died

I am in the stages of doing mine a 86 with 132000 and bad guides, so what I have done so far is I found another head and have the new guides in the new valves are in and lapped in nicely, getting ready for the springs, I got the gasket set, new front seal and assorted other parts from performance products as soon as the head is ready I am going to swap so I can keep driving. I was hoping I could leave the intake in place less to worry about,

Strider,

At the low mileage yours has travelled I would expect it would need little other than a head gasket and valve stem seals (plus valve cover gasket and manifold gaskets etc.) I did the same job on the M103 in my '90 300TE several years ago at about 145,000km (90,000 miles) and it needed only the above plus a very light skim to ensure the head was flat. After removing the head from yours, check it for flatness to determine whether it needs to go to a machine shop. I did the same job on my brother's '92 M102 engine at just 93,000km (58,000 miles) last year and the head was flat to within 0.0015". With a new set of valve stem seals and head gasket (plus the other necessary gaskets) it went back together without requiring the services of a machine shop. The M102 and M103 are very easy to do this work on. If you are comfortable with this sort of work, read the many threads that have been posted regarding these jobs and enjoy the savings and satisfaction of doing the job yourself.

Greg

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107.023: 350SLC, 3-speed auto, icon gold, parchment MBtex (sold 2012 after 29 years ownership).
107.026: 500SLC, 4-speed auto, thistle green, green velour.
124.090: 300TE, 4-speed auto, arctic white, cream-beige MBtex.
201.028: 190E 2.3 Sportline, 5-speed manual, arctic white, blue leather.
201.028: 190E 2.3, 4-speed auto, blue-black, grey MBtex.
201.034: 190E 2.3-16, 5-speed manual, blue-black, black leather.

If you'll search here and over on the Ritter-Easley list as well, you'll see that many have recommended flushing the oil contamination with liquid Tide Soap.