1990 200Q radiator blew up

[Keith Lawyer]

>Blown headgasket dumping compression into the cooling system? >>>>> Any
help is greatly appreciated.

Sounds exactly like when we warped a head on my old '89 200Q.  At first
I didn't put it together, and just kept replacing parts and hoses that
would blow off.  It blew out the cheesy plastic "valve thing" on the
backside of the motor near the firewall, then eventually the afterun
pump itself sprung a leak and the cap on the overflow was gurgling. 
Midnight in Fairplay CO, it wasn't pretty.

Similar symptoms, the gauge was reading high but not terribly high, and
Autocheck knew something was amiss.  The problem was that I didn't trust
the Autocheck and the multi-function temp switch was spastic at best, so
I didnt' know if I could even trust the stock gauge.

Anyway, sorry for my grim diagnosis

Keith L