I bought an 83 Volvo 240 wagon from a local mechanic for a thousand bucks with nice snow tires on original rims. The car needs to be repainted but seems to run really well. She fires right up in recent cold weather(20-30F), but does need a full 5 minutes to warm up or she runs rough.

I was not able to drive a bunch before I bought the car because the weather was wet, frigid, and the roads were ridiculous. Most of my driving was done later in the afternoon when it was dark.

Then this morning... the roads have been plowed and the weather has cleared so I was able to get her out on the road and now I am worried because even after driving her for 20-25 minutes the tail exhaust never stopped.

Is there any valid reason why the car would still be emmiting normal winter exhaust or is it more likely that I have a bigger issue... i.e. head gasket, etc...

Not sure this is relevant but the engine was modified to add a sort of warm air recirc function between exhaust manifold and radiator to assist with cold starts?

Not sure I want to know the answer to this one...

Thank you.