Changed head gasket, runs rough now! - PeachParts Mercedes-Benz Forum

Sugi · #1 06-08-2009, 10:12 PM

Ok, It's running great! Here's what I've learned:

1. Don't drop the chain or move the engine when removing the head.
2. If you do, it's not the end of the world, you will just have to very carefully check the cam and injection pump (I.P. from here on) timing.
3. You have to remove the oil filter housing part way to replace the I.P. - I took the housing part way out to remove the I.P. but I hear you can pull it w/o doing that, seems very hard. I removed the top oil line going to the cooler, both brackets holding the lines as they snake though the engine bay, and the 5 or 6 Allen (internal hex) bolts to move the pump. The bottom hose stayed attached. I used a 27mm open end wrench and a 24mm flat wrench used to remove fork caps on some mountain bikes (borrowed this from my L.B.S.- local bike shop-supposedly took them a while to get this tool, brand is Techno Nankai, Japan). I also had to shorten the short side of a Allen wrench with a hacksaw to get a two of the oil filter housing bolts. You can't get the bolts pulled out until you remove the housing- I just got them all the way loose so I could slide the housing over a little.
4. All I did was to line up the gap on the I.P. shaft with the mark on the housing (looked like a punched in line/mark). The engine was set at 24 degrees BTDC on the compression stroke of the engine (front cam lobes facing up and out as seen through the oil filler hole on the valve/cam cover).
5. Don't drop the splined sleeve that couples the I.P. shaft to the gear in the engine. I did and got extra practice removing and replacing the I.P. DOUBLE DOH.
6. The OM 617 N/A engine will apparently start and run if the timing is one tooth off on the cam AND the I.P. is 20+ degrees out!!! That's totally nuts. Of course it's warm out and the engine is a fresh Metric Motors rebuild (not sure why the head gasket failed but there was a headbolt looser than the rest right near the leak).
7. The I.P. timing being way advanced made lots of smoke and it sounded like a Mack truck.
8. The folks on the forum here have been a great source of inspiration and help. THANK YOU.