Posted by Lars BendOr e12z on February 03, 2002 at 11:10:43 from 66.62.152.12
In Reply to: 76 530i posted by karl sisson on February 03, 2002 at 09:00:07:
The 76-77-78 models had one characteristic flaw. May be an explanation for the engine at 60K, since these are easy 300K engines. I have had 3 77's and the problem caught up with me on one. Do NOT let this car run hot. If it get's hot, shut it down and fix the problem. If it has the stock exhaust, it is commonly referred to as the "thermal reactor" exhaust. It was an early effort to meet emission standards, by setting the engine to run rich and using a very hot exhaust system to burn of the excess fuel. This, in conjunction with a casting weakness on the original head, sometimes cause the head to crack.
It is entirely likely that the new engine has a later casting (done in 81). If you do not know this and the "thermal reactors" (noted by a massive exhaust casting about 4 inches in diameter, under a metal shield), then keep an eye on the heat guage... particularly since you are planning a long trip cross country.
I had absolutely no problem with two of my 77's, so hope this response is not too disconcerting. They are fantastic cars and there is a ton of info and help on this site. Have a wonderful trip, in spite of my caution.