Hi, I'm a relatively new member here... been reading through the many, many useful postings! I just bought a '79 240D for not too much money. A mix of good news and bad; the good news is that much of the car works and the body is rust-free. The bad news is that the car reportedly sat for five years, the front suspension needs a lot of work, and the brakes probably need top to bottom replacement. Not worried about the brakes, I can do that. I'll probably turn the suspension issues over to MBI here in Portland, and do it in two stages (cheaper).

The real issue, of course, is motor health. It runs rough when you first start it it, and has some blue smoke and diesel smell. This concerned me enough that I asked MBI to do a compression test on it. Here are the results:

Cylinder #1: 280 psi
Cylinder #2: 320 psi
Cylinder #3: 380 psi
Cylinder #4: 340 psi

After reading through the forum for a couple of nights I've come up with the following plan:

Adjust valves
Try the Marvel Mystery Oil treatment: remove glow plugs, squirt an ounce in, plug hole with paper towel, let sit a couple days, re-install glow plugs.
Replace oil with synthetic oil plus quart of MMO.
Drive it a couple times a week without holding back so much on demands on the engine (I'm usually a very low-key driver!). Go up some hills, run it at 65 on the highway, etc.
Monitor oil usage.

After a thousand miles or so, adjust valves, test compression again, and decide whether to look for a better engine or contemplate a tear-down.

Sound about right? Thanks for your advice.

Kurt

PS Pictures on another forum '79 240D

Forgot to add this, though you can probably deduce it... the car is a little low on power, though not terribly. I'm not well-calibrated on 240D's power, but it held 55 mph going up the 205 bridge here in town. It's also a little, um, zoomy... not much torque at low RPM, but once you get RPM past a certain point there's more power. I figure that is just the fourth cylinder 'coming on line' at higher RPM's (where the compression is less of an issue). Seems to start reliably at 50 degrees F with glow plug usage, just runs rough for a minute or two and smooths out pretty well.

The rough running on start up is almost certainly a bad glow plug. The compression is actually quite good for an old engine. I would just adjust the valves and drive it. The 240s don't have a lot of power to start with. Change fuel filters and air filter too. Brakes are very very durable. I would check the pads and simply drive it unless you have one sticking or it pulls under braking.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

X2 with Tom.
Give it a bit of running before you do too much to it. The valve adjustment is a good idea. I would hold off on the Marvel M oil unless it has had non diesel in it. In a couple of k miles have a closer look at it. Filters are a must.

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Grumpy Old Diesel Owners Club group

I no longer question authority, I annoy authority. More effect, less effort....

1967 230-6 auto parts car. rust bucket.
1980 300D now parts car 800k miles
1984 300D 500k miles
1987 250td 160k miles English import
2001 jeep turbo diesel 130k miles
1998 jeep tdi ~ followed me home. Needs a turbo.
1968 Ford F750 truck. 6-354 diesel conversion.
Other toys ~J.D.,Cat & GM ~ mainly earth moving

Are glow plugs usually replaced as a set? If not, is there a resistance test to determine which one is bad? EDIT: never mind, I found some threads in the archives!

The master cylinder is leaking, so I've got one of those on order from our hosts. The inspection from MBI said that the disks were out of spec undersize, so I was figuring on on eventually replacing those. Didn't order them yet, though.

Thanks for sharing your advice and experience.

Kurt