White smoke under load

I searched the forums for something similar but I had no luck so here goes....

I have a '94 Achieva, it sounds and runs fine...well not 100 % of the time.

If I am on level or even a low grade hill the car runs great, no odd noises no slips no problems. As soon as I attempt a hill the car gets through 3rd gear with no problem but then all of a sudden it wont get anymore power revs to 3000 rps and it wont get any higher nor will it shift to next gear but the thing is it pours massive amounts of smoke out of the exhaust. As soon as you hit level again it stops smoking and runs like the champ it has been since I bought it.

The oil is fine the tranny fluid is fine, the car runs great until you hit a hill...The smoke sorta smells like rotten eggs but it is faint not overpowering.

Any ideas on where to start here?

Two possibilities here, bad cat that is stopping the exhaust from leaving the engine. Second, bad intake gasket that is causing coolant to be sucked into the combustion chamber. Have the cat checked first as this will be the cheapest fix. If that does not fix the problem have a pressure test done on the engine to see if coolant is getting into the combustion chamber. You can also do this by checking the plugs.

Check the radiator for the presence of oil and the oil dipstick for the presence coolant IMMEDIATELY (it'll look like chocolate milk on the dipstick). If either case is true, you've blown a head gasket for sure. Warm up your checkbook or credit card... because if you have a dealer fix it, it isn't gonna be pretty.