Rebuild Kit?
 

I bought a 740 with the d24, I discovered the motor is very sludgey, I want to take it apart and clean it, but figured I should rebuild it while im in there. anybody know of a rebuild kit for one? or do I have to hunt down every part individually?

Sludgey as in coolant in oil?

Unfortunately, no "full engine rebuild kit" exists; you will have to assemble your needed items in bits and pieces.

the sludge doesn't look green tinted, and fresh antifreeze came out of the radiator. I think its just sludgey as in the oil wasn't changed as much as it should have been

Unless it has problems resulting from the apparent sludge (loss of compression or oil pressure, chronic turbo failures, etc), if the engine is healthy otherwise you can probably take some steps to clean it up without taking it apart and save yourself a lot of work and hassle.

A motor oil lab analysis (Blackstone, etc) would also be a good idea if you are concerned about the contents of the oil. Not expensive and it will tell you about the presence of wear metals or any contaminants like coolant or fuel.

If everything checks out well and you just want to get the inside of the engine cleaned up a little, doing a crankcase flush with diesel fuel will get you there, though it's a little tedious to do the repeated oil changes to get the fuel out afterwards.

Tell us a little more about the car and its history, sounds like you have something interesting with a 1988 740 TD. Is it a converted gas car or imported from overseas? Welcome to the forum.

it started as a 1986 740 TD. Bought it non running 10 miles from the ocean in maine, rustier than anything ive ever seen. I thought it was just rockers and trunk floor that needed replacing, but then on the trailer home, the framerails under the doors fell out because they were so rusty. I got the car home, got the engine running (air in the injectors had to bleed it out) and thought about what to do. at this point I found paperwork in the glovebox that indicated an engine rebuild was done at 190k miles, and the odometer read 256k when I picked it up. eventually I found a rust free 88 740 shell on craigslist, current plan is swapping the d24T into the 88 shell. currently have the motor out and am giving it a quick once over before it goes into the 88. I pulled the valve cover today and saw the camshaft was spotless with no sludge, the only sludge was built up around the oil fill cap because there was a small "shelf" where it could accumulate. gonna pull the oilpan and cylinder head and give it a once over and cleaning, and cant wait to get it into the car!

That is great news!

If the camshaft area was spotless, why go thru all the extra work of a headgasket R/R? Unless you saw other reasons for it (oil/water mix, external coolant or oil leaks)? Just clean up the valve cover and run it! After you replace the timing belt, that is. According to your mileage count, it's due for replacement.

Same for the oilpan-- why remove it? The bottom end on these engines is very robust. Really, the most common problems these engines encounter are:
1. Overheating warps the cylinder head;
2. Crank pulley not tightened to spec, loosens and causes piston/valve interference;
3. TB failure, causes piston/valve interference.
4. Running non- full synthetic motor oil wears the rings excessively.

One thing we have started to notice is that cars that have been driven delicately and for low miles tend not to fare as well. Might be due to high ratio of warmup cycles to overall miles, never really getting the chance to fully warm up.