Ford Repair: 1989 FORD THUNDERBIRD 3.8L NONSUPERCHARGED, water coolant, thunderbird 3

Question
I HAVE OVERHEATING WITH A ROUGH IDLE BUT RUNS GOOD AT SPEED.I DON'T SEE ANY WATER IN THE OIL.IT SMOKES WHEN I FIRST START IT UP, BUT NOT EVERY TIME.GOING DOWN THE HIGHWAY THE TEMP. GAUGE WILL RISE AND STAY THERE FOR A LITTLE WHILE AND THEN FALL BACK DOWN AGAIN.I JUST PUT A NEW RADIATOR IN BECAUSE MY OLD ONE HAD A CRACK IN IT.THE SMOKE THAT COMES OUT IS WHITE,BUT DOESN'T SMELL LIKE ANTIFREEZE.IT HAS A REAL STRONG TOXIC SMELL LIKE MAYBE CARBON MONOXIDE,BUT STRONG.I DONT KNOW IF IT IS A EMISSIONS PROBLEM OR ENGINE PROBLEM.I THOUGHT ABOUT CHANGING THE EGR VALVE,WOULD THAT HELP?    THANK YOU.               EDWARD

Answer
It sounds like the engine has a small leak at the head gasket, replacing bad head gaskets is a common repair on the 3.8L engine.  I would not drive this vehicle until the problem is diagnosed and/or repaired.  If a head gasket is leaking, it will get worse. It could leave you stranded on the side of the road, and cause further damage to the engine.  White smoke is only caused by water/coolant, a little is normal, because water is a by-product of fuel combustion and condensation.  I would remove the spark plugs and inspect them for traces of coolant, and while they are out, perform a compression test on the engine.  EGR Valves almost never go bad, and wouldn't cause the symptoms that you have.

I hope this helps,
Dave