Wrapping Up The Greasy Bits

The valve job / engine rebuild has now been completed, and took five weeks in total. Two of them was the wait for parts to arrive from Germany, and the rest largely queuing for the mechanic's time, a bit at a time.

I'm going to skip a little ahead since you've seen pictures of the air filter box being off and exposed cams.

Everything above the block removed

Much to my delight cylinder walls looked pretty much pristine

There was a very slight completely symmetrical circular edge on top of every cylinder wall, but apart from that they were mint. Piston rings for cyls 1 and 5 were inspected and appeared very healthy.

Three things were wrong with the valves. First, The rods were very worn and thus the valves jiggled about almost humorously. Second, the valve plates themselves were worn in the same way. Third, the corner in each valve, and the corresponding corner in the head were worn in a way that made it impossible to get a perfect seal.

Put those together and no wonder there was no compression.

Old stuff

So, got new valves, rods and seals/gaskets from Germany, and the heads went out to be machined back into health.

Refurbished heads

Refurbished head with new valves

After all this was said and done, it was time to start reassembling the engine bay again.

Gaskets

2007 NGK BP6ES's. They're the best fit for the M117 engine. They've been driven 3 summers and still look almost new. Nice.

It took about two days to put the engine back together, debug etc. It went pretty smoothly. The engine bay is damn crowded when you begin to do stuff like this, so I'm glad I had a mechanic do it. After some timing adjustments, tightening fuel lines and bleeding air out of the coolant system, she fired right up. For a little while she ran fine but started coughing and shaking again. After some debugging, it was obvious that one of the spark leads was bad. I had a set of new Bosch leads I'd ordered over the winter, so after having it thrown on today, she started running perfectly. And man, what a difference!

You can tell just by ear that it's running well. A V7 does sound very different to a V8. Now it sounds like it should, and it's a very different sound to the one I recorded back when the Magnaflows were installed. Apart from the sound, the shaking and coughing is of course totally gone. She pulls strong and smooth. There's oodles more power than before, and I haven't even been on true full throttle yet, too much ice and snow and running on winters.

Did I mention it sounds absolutely awesome now? It's slowly warming up outside, enough so that I can cruise with the window down, and let me tell you, it's everything I hoped for when I started planning the exhaust. It's somewhat quiet but somehow not. Inside there's this calm feeling, but even if you're just slightly on the throttle, or when you give it the beans, you get this distant thunder and a fantastic soundtrack bouncing off surrounding buildings.

This concludes engine maintenance. To recap, over the winter I went through a lot: new timing chain, timing chain guiderails, valves, head refurb, new seals&gaskets everywhere and new spark leads. Spark plugs, distributor cap & rotor (Bosch), pistons, piston rings, block, cams, etc. all look and feel almost mint.


After the valve job the gearbox was a bit asthmatic. It wouldn't change up if I was even slightly on the throttle, and it let the engine rev a bit too much. This turned out to be an easy one, the wire that goes from the throttle linkage to the gearbox is adjustable from the assembly between the engine and firewall, so after loosening that, the gearchanges are back to normal. I'm thinking of loosening it some more, for extra wafting.


At the very end of the final engine reassembly, we stumbled upon the cause for the high idle problem. It was a vacuum valve in the intake manifold, that had a broken plastic air line. Replace that and 30 euros later, I'm idling at about 700-800 rpms in neutral and 500 rpms in drive. Fantastic! Finally!

Drove the car home yesterday for the first time since the shit hit the fan last month.

It's been snowing almost daily for a week now, with 5cm and sometimes (like last night) almost 20cm of new snow. But like I said, it's warming up, and with efficient ploughing the streets are mostly snow-free in daytime. According to forecasts, the snowy period should now be ending, with average temps rising above 0 and snowfalls being replaced by rain, which should take care of the rest of the snow.


Right after Christmas, the passenger side orthopaedic seat controller broke, the same way the driver side one had done last fall. I was able to source a replacement from a donor W124 diesel. Worked perfect, no hisses inside again.


Current todo list:

• Clean up interior since the dirty stuff is now complete. (imminent)
• Detail engine bay also. (imminent)
• Have paint buffed. (In the spring, when snow's completely gone)
• Derusting a spot in the driver side rear wing, between a horizontal surface and the bumper. After that, rustproofing. I will probably do these next fall.
• Rework exhaust tips. They were supposed to be stainless, but aren't. Also, I'm thinking of changing the design very slightly. This will probably happen soon(tm).
• Replace or repair driver seat and armrest upholstery. Will look into this next summer.
• Fix some interior wood trim. Epoxy up one strip near the front passenger side air vent (soon). Try to locate some donor parts for cracked-lacquer ones in the doors. (ongoing)
• Replace antenna mast seal (soon).
• Adjust driver window position to fix wind noise (soonTM).
• Rip out accessory alarm and maybe bring back original Merc one. (I wish)
• Fix gear selector lights. Probably a loose wire. Requires taking apart the center console again, so not a top priority.
• Debug sunroof controls. Doesn't work exactly like it should, although both the functions are there and workable. Probably miswired or the switch is broken. Need to look further into this.
• Source a donor Webasto and bring back to factory specs using the stuff that's left from before the malfunctioning burner was ripped out. (again, "I wish")
• Keep trying to find an OEM leather gearknob. Changing it requires disassembling the center console also, so will probably happen when I can be arsed to do that.
• Find a silent diff with the LSD still working. (During the next 3 years probably)

As the Finnish saying goes: kovaa ajoa!