So the new car was giving us some troubles. A little bit of coolant leakage now and then resulted in a sloshing sound coming from the heater core behind the dash. Coolant leaks out, some air gets in, suddenly you have some sloshing when you rev the engine. No big deal…unless you’ve lost so much coolant that you end up with say, a warped head gasket. My old college ride GMC S-15 had these exact symptoms, and sadly, the above diagnosis. $600 lost.
As was the case with the Jimmy, I first assumed the coolant overflow tank was leaking (a common first generation MINI Cooper fail point until it was updated mid-run). Not so. Turns out the MINI R50/R53 thermostat housing is somewhat notorious for leaking. It’s plastic, unsurprisingly. I’ve also heard reports the Dodge Neon that used a nearly identical engine had similar issues…again, plastic parts. I ordered up some new parts from my the nearest MINI dealer and off we go.