Newbie: Should I buy or convert?
 

I live in the Monterey Bay Area of California and own a '92 740 turbo.
I'd love to have a diesel so my question is this; should I drop a d24t and manual transmission (M46, M47, or T5?) in my current car or should I just keep my eyes pealed for an older original?

In my mind it would be a lot of fun to do the conversion, plus I would still have a car with an airbag. On the other hand, I have no real experience with working on cars so it might be too far over my head (a good way to learn?). What do you guys think? What resources should I know about (greenbooks, tools, good threads to read, etc.)?

Feel free to PM me.

I need as much help as I can get so thank you!

Welcome aboard

I'm just outside Watsonville, and have everything but a good motor/tranny you would need to convert a car.
I even have parts for a VIN conversion if you like to play like that

The 91 is a little nicer car in several ways, but poses a SMOG problem as the motor is supposed to be no older than the chassis you put it in.
The swap is pretty easy as such things go, after all , the D24 will run fine with only one wire hooked up, and the car itself has all provisions for the diesel motor.

Lots more work, but the E300D Mercedes motor runs fantastic, and would be legal in your car, as would a VW TDI.

Alternately, 90% of the parts from your car would bolt right to an 83-86 diesel.

Thanks for the input.
I appreciate the offer to help, but it sounds like the BAR makes it impossible to actually use the car with a D24t. This would be my daily driver so SMOG is important. I'd like to eventually convert to B100 biodiesel so I don't think a TDI would work, plus it sounds like with amount of work it would take to mate it with other engines I might as well get an original and fix it up. What should I know about the original cars? What should I stay away from? I know there was trouble with weak head gaskets, but there was a steel fix to that right?

Thanks Again.

I know a few TDI folk who've been on B100 for years, not a lot of gelling/freezing issues around here.

Metal gasket is NLA in the US, but you can get one shipped from Europe for about what some of the shops charge for the fiber one.

cooling system, and improper timing belt service are the 2 biggest killers.

leakey injection pumps and bad glow plugs are a major causes of inoperative D24s, but not that serious.

The early subframes were prone to crack, but can be replaced in a day.
I think that's the major stuff.

There's the bare minimum of glowplug wiring, starter wiring and grounding.

I said run, not start.
You might need the ground, a hill will take care of all the rest, as will a jumper cable.

A jumper cable is still wiring, albeit temporary wiring :D

Although, if we're talking about using jumpers, you don't need any permanent wiring, just jumper cable the glow plugs then jumper cable the starter. Don't even need to keep a battery or alternator in the car.

On the subject of buying or converting, is the bellhousing bolt pattern on the block face the same as the 4 and 5 cylinder variants? They seem to be much easier to find, wondering how much hassle they'd be to drop in.

The 5 is the same but the 4 is different. The 4's are more plentiful but I think the 5 is no more common than the six, maybe more uncommon even...

Hm... yeah, probably easier to swap in an OM606 than the 4 then... plus the 4s don't have much power, especially not compared to a modified OM606.

Dunno about that, OM606 is pretty long and heavy; they suck to work on too, esp after the return lines start to leak fuel into the injector wells or when you have to pull the intake manifold off to do almost anything on the LH side of the motor. Don't think there would be much that is "easy" about dropping one of those in... 4cyl VW would not be bad, there was a guy on TB that put an AHU TDI into a 245 and I don't think it was a big deal, just not a bolt-in, since BH is different. I think he used a Toyota trans and an adapter.

An Audi five would not be bad, back of it should bolt together, parts in front probably bolt on to the block and head, suspect mounts would be only big difference. Euro 2.5 TDI would probably be most straightforward way to get something more modern and capable of higher output in there, structurally very similar to the older six.

Of course a D24T would be the easiest of all, cheapest, and nicest to listen to... way better fit than a POS Benz lump, and for what it would cost to even get a stock 606 in there, you could have a D24 turned up more than enough to outrun it anyway... :p