Old brittle plastic in the cooling system is not a good thing. After 15 years of being treated to hot coolant, plastic bits will degrade. Sometimes they break, and leak coolant all over the place. The plastic necks where the hoses connect on the radiator are notorious for failure. If one goes and you don't catch it IMMEDIATELY, your headgasket blows. A new Behr radiator is only $150, and really easy to replace on a ti.
The plastic coolant pipes on the engine are also ready to be replaced. All of them, on every ti, everywhere- if it hasn't been done, go ahead and do it. You don't ever want one of these to fail on you. __________________ *Except 318ti 
'97 318ti M-Sport
'95 M3
BMWCCA | 
Linear Mode
