The place to start is by having your mechanic perform a chemical test at the radiator for a leaking cylinder head gasket. Coolant burning in the engine will cause white smoke from the tail pipe. Also, combustion gases getting pushed into the cooling system can make it look like the coolant is boiling when in fact it is not. The clue is you will see that "boiling" before the engine has had time to warm up. If you have a temperature gauge on the dash, that can indicate the engine is not overheating when you see that boiling.
Also, be aware that on most engines, it is normal and acceptable for them to run between 210 and 220 degrees F. Or more, and the water in the coolant boils at 212 degrees. For every pound of pressure in the system, the boiling point is increased three degrees, so the common 15-pound radiator cap will raise the boiling point to 257 degrees. While not common, it is possible for a leaking head gasket to prevent that pressure from being developed or maintained. That will allow the coolant to boil when the engine is not actually overheating. Any other coolant leak can do the same thing, like rotted hoses, loose hose clamps, leaking core plugs or water pump, etc. If the test for a leaking head gasket comes back negative, have the cooling system pressure tested to check for external leaks.
It is almost impossible for an engine to burn a quart of oil in a day, even if you drive hundreds of miles. Instead, a leak is a much better suspect. Evidence of that should be fairly easy to spot when the vehicle is on a hoist. When an engine burns an excessive amount of oil, you will see blue smoke from the tail pipe, and it can be so bad that you wont have any mosquitoes for miles! But even that wont use up the oil as fast as you are describing.
Sunday, November 13th, 2016 AT 6:28 PM