Mods
Floorpan cistern, for on the go rainwater collection needs
Custom floor pan drains
Dump tires, unbalanced
Custom T-iron hood release
Rear quarter panel air vents
Painters tape/caulk weather stripping
Rounded out transmission drain plug
Custom fusebox knob
Rear muffler delete
Demon possessed cooling system
Self flushing radiator
Semi-permeable radiator vanes
Carbon-sequestering carpet
Ecological microcosm for a fuel tank
Custom floor pan drains
Dump tires, unbalanced
Custom T-iron hood release
Rear quarter panel air vents
Painters tape/caulk weather stripping
Rounded out transmission drain plug
Custom fusebox knob
Rear muffler delete
Demon possessed cooling system
Self flushing radiator
Semi-permeable radiator vanes
Carbon-sequestering carpet
Ecological microcosm for a fuel tank
Build story
This Inline 5, turbodiesel 1985 Mercedes-Benz 300CD is nicknamed Ol' Mossy. The engine is an OM617 and the Transmission is a 722.3 4G-tronic automatic. This is my first revival and I’ve been documenting my progress on YouTube. It was abandoned in front of my uncle's tractor shed for at least the last 16 years. It was driven by several of my relatives before being parked. One cousin drove it all throughout college, it was a graduation gift for another, and one took his driving test on it. Ol’ Mossy was eventually bartered away by my uncle to a good friend of his in exchange for some construction work at his oldest daughter’s home site. The thing is, the fella never came and got it. We don’t know why. He lives a mile and a half up the road and used to flip cars/boats/heavy equipment/parts/scrap as a hobby, and he was notorious for his proficiency at it. It’s a mystery to me and my uncle. He ain’t dead, he still lives up the road, he doesn’t remember why either. It’s weird, but I digress. Fast forward to 2020 when I got my grubby mitts on it. After cramming the wrong size battery out of my daily into it and then pumping 5 gallons of red wine colored, gun solvent scented offroad diesel and algae soup out of the tank, I was able to get her to breathe again. I drove it out of its grave and limped it a mile down the road on delaminating tires to my grandparents house. There I could work on it more easily. Also the muffler fell off enroute but luckily this car is so fancy that it has TWO mufflers. Now that’s luxury.
I'm still working on it and its not roadworthy yet, but I'm making good progress. (It’s my first revival, I’ve never worked on a diesel nor an import, I don’t have a shop at the site, and I get at best one day a week to work on it, so cut me some slack here. I’m tryin’ my derndist.) This car has passive aggressively been fighting me at every turn. It seems every time I fix something, I break something else or am foiled by them German engineers. The two big gremlins I've been contending with are the cooling system and a rain leak into the cab. The cooling system is packed with sediment and jellied coolant/rust. I've cleaned and tested the thermostat, replaced the water pump, and run 2 bottles of flush along with 60 gallons of well water through the system. Now it's finally starting to look like 5 year old coolant when I run it through the engine for 30 minutes and drain the block, rather than beef broth. In their grand wisdom, the Mercedes engineers integrated the trans cooler into the radiator and that opened up another cavern in the rabbit hole. I just got the rad replaced yesterday and haven’t had a chance to test it yet on account of the empty transmission. (I did that after I rendered the video for this submission.) The other gremlin is that there is a massive hole in the corner of the engine bay between the inner fender and the firewall. All the rainwater running down the windshield or directed by the hood sill funnels straight into the driver's floorboard instead of the wheel well. This led to the floor pans filling 2-3 inches deep with water and then moss growing on all the carpets. It was like a mini-greenhouse. After a year of efforts, I've finally given up and drilled holes in the floor pan. I just can't keep the water out and I've exhausted my sanity. Send help.
In addition to all that, I've done the following: new battery, oil change, air filter, transmission filter/gasket, trans cooler soft lines, brand used tires, radiator cap, fuel return line, drained the fuel tank, cleaned the fuel strainer and sender unit, put biocide in the tank, fuel hand pump, hood latch, makeshift hood release, rehung the exhaust, air cleaner mounts, oil fill gasket, bled the brakes, diff oil change, and some other little things. I’ve got painters tape covering all the weather stripping and the aftermarket speed holes as well caulk around the sunroof to keep the rain out. I’d have preferred not to caulk it but it’ll come back out when I need it to. I hope.
There's still much to do, including: fill the transmission, accelerator linkage pivot mount, V-belts, clean the fuse box, brake job, run diesel purge through the pump, fuel filters, motor mounts, power steering filter/fluid, timing adjustment, timing cover gasket, fuel tank cleaning, glow plugs, and the list goes on. You know how it is. And that's not even addressing the body or interior. Just the mechanics. Thankfully, the engine appears to be in great shape at 174,000 miles. I believe it costs a fortune to rebuild an OM617.
My hope is to make this a goin’ to town rig and to help preserve a small bit of my family's history. Every one of my close kin has a fond memory of this little turbodiesel and I want the coupe to hang around long enough for me to hear the rest of those stories. She'll never be pretty but I think she's still got some legs left in her. I pray with a little (or a lotta) bit of effort she can stretch those legs and run again.
I'm still working on it and its not roadworthy yet, but I'm making good progress. (It’s my first revival, I’ve never worked on a diesel nor an import, I don’t have a shop at the site, and I get at best one day a week to work on it, so cut me some slack here. I’m tryin’ my derndist.) This car has passive aggressively been fighting me at every turn. It seems every time I fix something, I break something else or am foiled by them German engineers. The two big gremlins I've been contending with are the cooling system and a rain leak into the cab. The cooling system is packed with sediment and jellied coolant/rust. I've cleaned and tested the thermostat, replaced the water pump, and run 2 bottles of flush along with 60 gallons of well water through the system. Now it's finally starting to look like 5 year old coolant when I run it through the engine for 30 minutes and drain the block, rather than beef broth. In their grand wisdom, the Mercedes engineers integrated the trans cooler into the radiator and that opened up another cavern in the rabbit hole. I just got the rad replaced yesterday and haven’t had a chance to test it yet on account of the empty transmission. (I did that after I rendered the video for this submission.) The other gremlin is that there is a massive hole in the corner of the engine bay between the inner fender and the firewall. All the rainwater running down the windshield or directed by the hood sill funnels straight into the driver's floorboard instead of the wheel well. This led to the floor pans filling 2-3 inches deep with water and then moss growing on all the carpets. It was like a mini-greenhouse. After a year of efforts, I've finally given up and drilled holes in the floor pan. I just can't keep the water out and I've exhausted my sanity. Send help.
In addition to all that, I've done the following: new battery, oil change, air filter, transmission filter/gasket, trans cooler soft lines, brand used tires, radiator cap, fuel return line, drained the fuel tank, cleaned the fuel strainer and sender unit, put biocide in the tank, fuel hand pump, hood latch, makeshift hood release, rehung the exhaust, air cleaner mounts, oil fill gasket, bled the brakes, diff oil change, and some other little things. I’ve got painters tape covering all the weather stripping and the aftermarket speed holes as well caulk around the sunroof to keep the rain out. I’d have preferred not to caulk it but it’ll come back out when I need it to. I hope.
There's still much to do, including: fill the transmission, accelerator linkage pivot mount, V-belts, clean the fuse box, brake job, run diesel purge through the pump, fuel filters, motor mounts, power steering filter/fluid, timing adjustment, timing cover gasket, fuel tank cleaning, glow plugs, and the list goes on. You know how it is. And that's not even addressing the body or interior. Just the mechanics. Thankfully, the engine appears to be in great shape at 174,000 miles. I believe it costs a fortune to rebuild an OM617.
My hope is to make this a goin’ to town rig and to help preserve a small bit of my family's history. Every one of my close kin has a fond memory of this little turbodiesel and I want the coupe to hang around long enough for me to hear the rest of those stories. She'll never be pretty but I think she's still got some legs left in her. I pray with a little (or a lotta) bit of effort she can stretch those legs and run again.