M103 valve stem seal replacement complete - epilogue

[d.delano]

Just did the stem seals on my '93 190E 2.6 177k miles. Overall, once you get the angle of the dangle it's quite easy. I expected a bigger challenge. Biggest frustration for me was keeping the engine from turning over.

I developed my own system. I used this pressure gauge/dongle thing that fit into the spark plug hole. Pretty standard tool. At first I tried watching the guage to see when the needle reached its zenith, but that method sucked so I did some analysis. I found that when both cam lobes were at the 11 and 1 o'clock positions, I could look into the hole and see the top of the piston. Also, I could then apply air pressure without the engine turning over. Also, the PeachParts Wiki is wrong about the seal installation sleeves - they are for the exhaust valves only, not the intakes as the Wiki describes. No biggie.

Cheapo McParts spring compressor was a bit fiddly but worked out just fine. Popped all the old seals out with just my fingers. They weren't hard, weren't soft either. They were original. Some of them had the internal ribs worn flat. Cam lobes/rocker surfaces looked like brand new, valve stems had no signs of scoring and were tight.

However I was troubled by the amount of sludge in & around the tower bolts, and the little pieces between the lifters & the tops of the springs (buckets?) had sludge blocking the holes. Also, there was sludge in the overhead oil tube big time and the inside of the valve cover was just gross. Gritty nasty sludging. Carbonized oil? Looked like peeling paint. Overall not too bad considering the age/mileage, but given the care this car has had in its lifetime I expected better.

I don't know what improvements I can expect from this, I got a ***** mother of an emissions test coming up and I'm hoping that this 19 year old gross polluter will pass after some massaging. Last time I smogged it the NOx was near the ceiling.

Now I get to go to the junkyard and try & find a working EGR valve. Joy!

I'm in middle GA right now at my pop's place - anyone in the area know of any good scrapyards?