Studying D-Jet means you've made up your mind on a 280SE or 280SEL 4.5 I take it. Some 4.5 specific items to look for:
# Worn cams. More common on m116 and m117 V8s with neglected camshaft oiler tubes. Be aware that these cams should not be reground, but rather replaced.
# Timing chains. A bad timing chain can cause catastrophic valve damage, especially common on m116 and m117 engines. The stretched chain causes the guide rails to break from stress, and the cam “skips time” causing valve/piston interference. $2000 per side to repair, minimum. A new chain and guide rails is under $150, and takes about 4-6 hours for a novice DIY to do.
# Trigger points (if applicable) – Many 3.5 and 4.5 engines have dirty trigger points, causing hesitation when cold and poor running (the feeling of running on only 2, 4, or 6 cylinders).
http://mercedesw108w109.com/buying.html
- Like the Aus guide but tailored for the States.