Overheating and dying batteries
 

To start, my Miata has never ever had an overheating issue. After running the car hard, even in the summer (pretty mild in BC), the car has never seen anything passed 12 o'clock on the temperature gauge. I changed the oil in the Miata before setting out on my California road trip last week and I fear that my first ever oil change is causing this issue. I replaced the oil with 5w30 synthetic oil and basically just set off on the trip. After hitting the heat of Oregon on the I-5, I noticed some scary overheating (hitting 1 o'clock and climbing) but this was quickly fixed by turning on the secondary fan and keeping my speed down to 60 mph. Great. Next problem: Apparently running the secondary fan destroy's my battery and stops the car from being able to be started -- after running the secondary fan and riding the highway for a good 4 or 5 hours, we stopped to get some gas and supplies just to find that the engine would not turn over, this issue was solved by bump/push starting the car -- whhhhhyyy?

At this point in the trip, I have traveled about 1000 miles and bump started the car with the help of random strangers about 5 or 6 times. I also noticed (for the first time ever) that there was some smoking out of the exhaust - inconsistently (smokes a couple of seconds, then doesn't for several minutes, etc.) -- this doesn't sound good...

I'm not really sure what I am able to do to solve/diagnose these issues before I return home, but I am hoping that someone might have some insight, ideas, or possible solutions while I'm out running in the amazing California heat.

Thanks in advance. Sorry for the word cluster fuck. On trip. Frantic.

Sounds like either a dead battery or dead altenator. There's no way that traveling on the interstate for 4-5 hours wouldn't charge the battery. Either the battery won't hold a charge or the altenator won't give it one.

The battery is easy enough to have tested at an Autozone or similar store, I think you need the altenator out of the car to be tested.

If it clicks like a dead battery after 30 minutes of being hooked up to a charger or another vehicle, battery is probably shot or on its last leg.

Start the car and hook up a voltage meter. What does it read? Unless you're running some crazy fans, 2 fans should be within voltage limits.

At highway speeds your radiator is getting more air from the speed than the fans can provide. Check your thermostat. Turn on your heater, is it even heat or does it fade away at spots?

On the other hand you say you got a smoke out of your tail pipe. Do a compression tests and pull the plugs. Hope it's not a blown head gasket.

I'm leaning towards the alternator. My car has a voltage gauge hooked up and its showing around 12 volts for the most part. When the car wouldn't start, the voltage was reading closer to 11 volts. The other odd thing, and this probably has something to do with the way the fan was hooked up, is that when thee secondary fan gets turned on, the voltage drops around 1 - 1.5 volts. I'm guessing that has something to do with this...

When I turned my heat on, it was very constant. And very very hot. Maybe my intercooler and radiator are full of bugs? Would a clogged intercooler restrict airflow enough to the radiator to stop proper cooling?

I have never had a smoking problem before, I thought that I might have been using a lighter weight oil or something and that might be causing it to smoke. Either way, I will have to do a compression test and such when I get back home.

Maybe your alternator died/is dying, and the lower voltage made your temp sensor read hotter?

Well then your WP should be fine, now check the thermostat, with how cheap they are, might as well replace it to be safe. Check the voltage while the car is running.

WP? Voltage was mostly around 13 volts when running.

I made it back to Canada with out many more issues, just one more bump start and reduced speed on the freeway... and 9 hours of driving in the cool cool California air to make Portland by 3am after being stuck in Redding with the I-5 closed. Anyway, car hates California heat but loves the cool and humid air up here.