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One should expect there to be uneven cooling on these engines. On the Type 1, the oil cooler blocks some airflow to cylinder 3, making that cylinder run hotter than the others. On the Type 3 and Type 4 with stock cooling, the 3/4 pair tend to run hotter than the 1/2 pair because of the way the cooling system is arranged. Typically, when measuring actual head temps at the spark plugs with a CHT, the 3/4 bank will typically run 30-50dF hotter than the 1/2 bank, and the 1/3 cylinders (farthest from the fan) will run 15-20dF hotter than the 2/4 pair. A 50-75dF difference between 3 and 2 (hottest and coolest) is not unusual. In the flat cooling systems, most of the airflow is towards cylinder 2, and only some of the air goes towards cylinder 4. The "rear" cylinders get the air already pre-heated by the front cylinders, so they run hotter. Nothing to do with uneven tuning, just the way things work with the flat cooling system. The doghouse cooler works better, and if the oil cooler is removed and made remote, all of the cylinders tend to run pretty even in temp. Jake Raby makes another doghouse type cooler for the Type 4 that cools everything pretty evenly. Won't work on a Type 3 or 4 chassis, though. __________________________________ Yahoo! Mail Stay connected, organized, and protected. Take the tour: http://tour.mail.yahoo.com/mailtour.html ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ List info at http://www.vwtype3.org/list | mailto:gregm@vwtype3.org ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~