[Vwdiesel] Ways of cooling an AAZ

[travis gottschalk]

The fact you can drive it at hwy speeds without boiling over means you aren't terrible either. These do get warm I don't have something to actually read the temp gauge in dF I do know where the boil over point it and it does swing closer to the side when on the interstate. The oil also gets up to 265 on the interstate. My issue was there wasn't a baffle in the radiator to force it through to get cooled. It was in the top and out the bottom without even reaching the fan switch to turn the fan on even though it was boiling over. Brand new radiator. The 1.6 NA put 10K miles on that radiator before the problem was found. New again radiator-same problem again only the radiator shop (rather then parts store other was bought through-which I still got the money back) took the radiator apart and put a baffle in. But the end caps on it were metal so it was easier to do that. So I had two radiators new in a row from different makers (plastic end caps on first) so that is always a chance that is what happened to you. 

As for the oil cooler the stock one hooks to the coolant likes on the head/block/water pump area and are the AAZ water line specific. The bypass hose that goes from the head to the waterpump when the thermostat isn't open. That hose has a connection to connect to the oil cooler and then it hooks into the small heatercore return line that goes to the water pump. The top water flange should have a connection to go down for the bypass hose and a connection for the top radiator hose. The stock core keeps the oil temps in check but it does warm up the coolant more. As a side benefit it warms the oil in the winter faster but and aftermarket cooler would cool it better if done right and keep both the oil and coolant cooler but in the winter you don't get the warming of the oil as fast. You would want a thermostat regulated cooler sandwich so the oil in the winter wouldn't flow through it till a certain temp so you don't have so high of oil pressure for so long in the winter. 
Travis G.