The little elantra who couldn't

My daughter has a hand me down 2004 hyundai elantra. She took the car this summer with her while working at camp, which is located at the top of a mountain in CA. This past weekend, while coming back from her day off, the car kept stalling while going up the steep mountain. We finally had to have it towed into the closest town.



The mechanic drove it for 2 hours and couldn’t find a thing wrong with it. As a protective mother, I don’t want my daughter getting stuck going up the mountain again.



Does anyone have any ideas of what they may be able to check for to fix the problem, as the usually diagnostics didn’t produce anything.

How many miles? Manual or Automatic? How much gas was in the tank when your daughter was driving up the mountain?

The car has about 70,000 miles on it. It is an automatic and the tank was about 1/2 full. As an FYI, in the past 18 months I’ve replaced the following: battery, alternator, timing belt, water pump,tensioner, rollers, all accessories belts (3), spark plugs and air filter, performed tranny flush with filter.

Fuel filter?

The mechanic should have used 1-3/4 of those two hours checking for stored fault codes in the ECU, testing the fuel line pressure, and connecting the engine ot an analyzer.

My point is that there are a number of diagnostic tests and evaluations that can and should have been done in looking into the problem. The codes could be checked, the fuel system could be checked, and a good evaluation of the ignition system could be done. Filters could be chenged. Even the EVAP system could be checked if necessary. An initial “test drive” to try to verify the symptoms is valid, but 15 minutes is all that’s needed.

The mechanic said he checked for codes and none came up.

How big a mountain? California has some pretty big ones. And how hot was it when she ran into trouble? It gets pretty hot in the mountains on Summer afternoons. If the car had to climb thousands of feet there might be a temperature or altitude related problem that the mechanic might not see in town. Did the check engine light come on?

Modern cars are much better about altitude and load than those of yesteryear, but still, trying to climb steep hills is harder work than they do around town. And if they have to do it in the thin air of high altitude and cope with heat as well, that could cause problems.

If nothing else, I’d consider replacing the fuel filter. If partially plugged, it could cause stalling when the engine is under load, and changing it every 60k miles or so won’t do any harm. Replacement shouldn’t cost a lot.

I’ll give it a try. Thank you.