Under the Hood: Donít put off fixing cooling system leak

McClatchy-Tribune Information Services

September 30, 2019

Q: Iíve noticed some spots on the driveway beneath my car that I believe are antifreeze (orange). I have an intense schedule right now that will make it difficult to have the car serviced. Is it acceptable to add a container of stop-leak to fix the problem?

óMelissa B.

A: Melissa, I have doubts this will help, and the consequences of possibly overheating the engine are ugly. Before driving further, can you please check or get the coolant level checked, and top off as necessary? Removing the radiator or expansion tank cap is absolutely dangerous unless the engine is cold, as the warm/hot coolant will be under pressure and can cause serious burns if it suddenly escapes!

If coolant is needed to bring the radiator and/or expansion tank or overflow bottle to the correct level, tap water will do for a quick fix, until the system is inspected and repaired (coolant will likely be renewed upon repair). Even if the leakage rate is slight (a few drips here and there) Iíd seek service as soon as possible!

There are many reasons a cooling system may leak. Hoses can develop cracks or splits, a hose clamp may be loose or improperly seated, a gasket between mating engine components may be failing, the radiator or heater core may be leaking, or the water pump seal may be leaking. Stop leak products are sketchy at best, and would likely only be helpful in the case of a tiny radiator or heater core leak, and the fix often doesnít last very long. Iíd hesitate also adding anything that could possibly contribute to passage clogging.

Itís impossible to tell you what to expect for a repair. A leaky hose would be your best-case scenario; a leaking heater core or corroded engine component (occurs due to lack of cooling system service/coolant replacement) would likely be the worst.

Promise me youíll move on this as soon as possible. The consequences of an overheated engine can be major and unpredictable.

Q: Iím trying to teach my daughter, a new driver, the best ways to drive efficiently so as to produce the least emissions. Do you have suggestions?

óVal T.

A: Reducing emissions and maximizing fuel economy go hand in hand. Maintaining correct tire pressure, performing appropriate vehicle maintenance and practicing efficient driving habits can go a long way to improve operating efficiency. Todayís cars and trucks are pretty good about letting you know of performance faults via the Onboard Diagnostics II systemís check engine/service engine soon light. Virtually all faults or conditions that might result in increased exhaust emissions (and reduced engine efficiency as a side benefit) will result in an illuminated light and a stored diagnostic trouble code.

When it comes to driving habits, minimizing the quantity of cold starts via trip consolidation is huge, as emissions are much higher then. Anticipating slowdowns ahead and easing up early on the throttle, rather than braking, saves fuel. Brakes convert kinetic energy to heat, which is about as wasteful a process as one can get!