Dan Weeks wrote: >> Wow. So the thing has an aluminum head? >> If the stupid thing can't take a minute at 120C or so, then I'm not >> sure it's such a good car afterall. >>
Virtually all of the 1st generation aluminum diesel heads (from almost all Euro car makes) were less than spectacularly robust (especially those with turbo equipped engines) and considerably more likely to fail than older engines with iron heads. The 2nd and third generation heads were virtually as durable as the iron heads. The Mercedes heads used in 603.96 engines (1986 Federal certified 126.125s) that were not equipped with factory oxidation traps were very much less likely to crack than the '86 California and '87 Federal cars were all trap equipped. The problem wasn't that the head wouldn't stand 120 deg C, but that it wouldn't tolerate prolonged coolant boiling which requires about 4X the heat to move the coolant through the the phase change window. Trap equipped cars that were largely city driven in stop and go driving experienced a large number cracked heads (between 20-25% by my count). This was because a partially blocked trap (very common in city driven cars) exposed the engine to temperature extremes in stop and go driving with the AC on. If the head didn't crack, once the trap was remove the frequency of head failure dropped, but did NOT vanish. That's because often the head would actually crack under the excessive trap generated heat, but didn't fail until the head was disturbed (like by pulling the head, replacing the head gasket or being seriously overheated). I own an '87 300TD and the service I've received from the 603.96 engine has been exemplary - super car, super engine, super service. If it were to fail tomorrow, It has been the most satisfactory car I've ever owned (but hardly the cheapest to own) for the 20+ years I've owned it! Marshall -- Marshall Booth Ph.D. Ass't Prof. (ret.) Univ of Pittsburgh School of Medicine [EMAIL PROTECTED] _______________________________________ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
