Q: I have a 2001 Ford Taurus with the 3.0-liter V6. It seems to be losing engine coolant but I never see any on the ground after I park it. I added 1 gallon of coolant on Nov. 10 and another gallon on Dec. 18. Now, I need to add more. Any ideas?

A: Anytime an engine loses a significant amount of coolant without leaving any evidence of leakage on the pavement under the car, a failed intake manifold gasket or cylinder head-gasket is suspect. Check the oil dipstick for signs of coolant getting into the engine oil — a higher than normal reading, a milky buildup on the dipstick or the smell of antifreeze can indicate a problem.

If the oil is clean, it's very possible the coolant is being drawn into the combustion chambers and vaporized. Sometimes, a trail of white smoke indicates coolant consumption, but this time of year normal condensation in the exhaust can mask the coolant smoke.

The simple do-it-yourself test is to check for excess bubbling in the coolant. With the engine dead cold, remove the radiator cap and start the engine. Exhaust gases forced into the coolant from a head-gasket leak can create excessive bubbling in the coolant, potentially pushing coolant out of the cold radiator.

The two most common professional tests for head gasket failure are a cooling system pressure test to determine if the sealed and pressurized cooling system is holding proper pressure after shutdown, and a litmus-type test of the coolant to determine if hydrocarbon (combustion) molecules are present.

Q: We have a 2012 Ford F-350 4X4 truck we bought new in October 2011. In February, the radiator had to be replaced due to leaks at the seams. Why would a truck with under 50,000 miles have a radiator that leaks at the seams? It cost us $1,200 to replace as the dealer said it was not covered under the factory warranty or the extended warranty we purchased when we bought the truck. We are disappointed truck owners.

A: I would be, too. The basic 2012 Ford new car warranty covers most everything but wear items for three years/36,000 miles. On top of that, the drivetrain is covered for five years/60,000 miles. If the radiator in your truck failed after 36,000 miles, it would not be covered by the new car warranty nor the drivetrain warranty.

I don't know which extended service plan your purchased, but of the four extended service plans offered by Ford, the top two plans — Premium Care and Extra Care — do cover the radiator. Ford's ESP Basic Care and Powertrain Care service contracts do not.

Assuming the radiator was not covered by warranty, I would not hesitate to ask the Ford dealer to ask Ford to help with this repair with a customer "goodwill" adjustment for all or part of the cost. In my opinion, a radiator should not develop seam leaks at this low age and mileage.

Q: Ever since I had my 2006 Jeep Liberty in for a diagnostic test, I've been unable to fill up my gas tank without having to trickle in the gas. The pump clicks off right away like the tank is full. There's a lot of pressure released when I first take the cap off. Any ideas?

A: My ALLDATA automotive database pulled up Chrysler TSB 14-001-09, dated September 2009, that outlines a series of tests to determine where the restriction causing slow refueling is located. Since you indicate that significant pressure is released when the fuel cap is removed, the charcoal canister or its control valve are suspect. Other components of the evaporative control (EVAP) system that could contribute to this problem are the vapor recirculation tube and the fuel filler tube.

Plugging a scan tool into the vehicle's diagnostic link should not affect any part of the EVAP system.