QUESTION: I am the original owner of a 2002 Chevrolet Silverado pickup with the 5300 V-8 gas engine. After driving it, there is a distinct smell of antifreeze when you are outside the vehicle. There are no apparent leaks and the fluid level remains fairly stable. I have had it checked but nothing was found. It has gotten worse the last few months. Any ideas on how to proceed?

ANSWER: Check the simple stuff first. Is the radiator cap sealing and holding pressure? Is the heater core leaking coolant onto the floor of the passenger compartment? Is coolant weeping from the bottom of the water pump?

Check the oil on the dipstick carefully. Is there any evidence or odor of antifreeze? Has the level on the dipstick increased? The primary mechanical danger from coolant leaks, beyond the potential for overheating, is the coolant reaching and contaminating the engine oil. Ethylene glycol doesn’t lubricate well, and it’s corrosive to aluminum pistons. It tends to strip oil from cylinder walls and bearings, leaving these components exposed to wear and damage.

To identify internal leaks, pressure-test the cooling system and/or have the coolant chemically checked for the presence of hydrocarbons from the combustion chamber. Head-gasket leaks or cracked cylinders are the types of problems that can kill an engine.

A coolant leak from the throttle body/intake manifold gasket could allow coolant to be drawn into the combustion chambers and burned, leaving little or no evidence. But it won’t do the pistons or cylinders any good.

GM issued technical service bulletin 06-06-01-019B, dated June 2007, that identifies a possible coolant leak into the oil from seepage from casting faults in specific cylinder heads manufactured by Castech. Remove the valve covers, check for the Castech casting logo and inspect the oil drain back holes for clean, shiny areas indicating evidence of coolant leakage. If this is the issue, the bulletin calls for replacing the cylinder head(s).

Q: Recently my daughter’s friend bumped into my 1996 Dodge Dakota and did $1,200 worth of damage. I promised my family and the body shop I would get it fixed. Some people say I should just keep the money. Is that legal? Or just unethical? Or neither?

A: I don’t think this is a question of legality or ethics; it’s a question of what you want. Do you want your vehicle repaired? Or if it’s fully functional and not damaged to the point of being unsafe or illegal to drive, are you OK driving a 17-year-old truck with damage? It’s your truck, and the other party is responsible for the cost of repair, but it’s your call on whether you have the vehicle fixed. With that said, a promise is a promise.

Your unrepaired vehicle may no longer be eligible for collision insurance on your policy due to the damage and decreased value. But with the age and value of your truck, collision coverage wouldn’t be worthwhile anyway.

Q: We have a 2005 Chevy Tahoe. The last couple months the speedometer is sticking. Sometimes when I start the vehicle in park, it might read 50 miles per hour. When I start driving it will go up from there. Other times it starts at zero then sticks at 55. Any suggestions?

A: Contact your Chevrolet dealer, provide the vehicle identification number of your Tahoe and ask if GM’s "07187C — Special Coverage Adjustment — Instrument Panel Cluster Gauge Needle Function" covers or applies to your vehicle.

This bulletin identifies a potential issue with instrument cluster needles sticking on a number of 2003-2005 GM trucks and SUVs. The "special coverage adjustment" covers replacing the instrument cluster at no cost on affected vehicles out to seven years or 70,000 miles from the original date the vehicle was put in service. For vehicles with mileage in the 70,000-80,000 range, GM will provide the instrument cluster at no cost, but not the labor.