West Coaster fears salty undercarriage from East Coast roads

Dear Car Talk:

I’m on a six-month visit to the East Coast from my home in the Pacific Northwest and brought my 2008 Toyota Tacoma with me. While driving the Massachusetts Pike and the Taconic Parkway might give me the boogaloos, I’m actually more scared of all the salt on the roads and what it might do to my NW virgin undercarriage. Everyone (including my new mechanic here) stares at my Tacoma and says it’s in really great condition, which only makes me worry more.

So, here's a two-part question: How do I prevent the salt from settling in and doing its oxidizing worst to my pick-up beauty? And, is going to those fancy car washes I see here sufficient to keep my "Silvie's" under-regions tidy? Thank you! – Tami

RAY: Don't worry, Tami. For six months, I think you can keep your pickup truck's nether regions from being completely despoiled.

You’re absolutely right that the salt they use on the roads in the Northeast during the winter wreaks havoc on cars. It causes the cars and their parts to corrode more quickly than they would otherwise. Being in the car repair business, I very much appreciate that.

But given the brief length of your stay, and that at least part of it is not in the winter, I think you can minimize the effects on your truck with a few precautions.

When there’s a snowstorm, the roads get salted immediately. In fact, it’s not unusual to be driving behind a salt-scattering truck while it’s snowing, and having salt actually sprinkled all over your car as if you were driving a baked potato.

The salt’s job is to melt the snow, and it does that. But it creates a salty, slushy gruel on the road that gets efficiently splattered all over your truck – particularly the undercarriage and fender wells.

It’s the gruel that’s most worrisome. So that’s what you want to get off your car.

The best plan of action is to wait a few days or a week after the storm. By then, the roads have often dried out, and while there’s still salt on the roads, your tires aren’t slinging a wet slurry of salt all over the bottom of your car.

At that point, go to a carwash, and pay for the optional undercarriage cleaning, which I think you can get now on a 30-year mortgage for about 4%.

You’ll still get some salt on the underside of your truck after that – you can’t avoid it all – but the worst of it collects during those first few days after a storm when a high concentration of salt is mixed with slush.

If you wash off the worst of it soon after each snowstorm, and then every few weeks in the winter to get any residual salt, you ought to minimize the East Coast seasoning your Tacoma gets, Tami.

Mind the gap when changing out spark plugs

Dear Car Talk:

I just changed the spark plugs and the coil bar on my 2014 Chevy Sonic. The engine starts, but won’t go over 3000 RPMs. Did I do something incorrectly?

– Max

RAY: Given that this happened immediately after you worked on the car yourself, I'm going to put my money on "yes," Max.

Actually, it may not have been your fault, but I’m guessing that something’s wrong with the spark plugs. If the spark plugs can’t make a big enough spark, the engine might run fine at lower speeds, but may fail when you try to rev it up and need that bigger spark.

You’ve heard of spark plug gaps, right? The manufacturer determines how much space there should be between the spark plug’s two electrodes. That determines how far the spark will jump, and how big a spark you get.

Most spark plug gaps are somewhere in the range of 1 to 1 1/2 millimeters. When we install spark plugs, we always check the gaps. Why? Well, some come out of the box perfect. But some don’t. Who knows why? Maybe someone dropped a crate of them off the ship in Long Beach while they were unloading. Or maybe you dropped one on the garage floor.

The size of the gap is very important.

If the gap is too small, there’s not enough room for the spark to jump. So the spark won’t be big enough and hot enough to combust all the fuel and air coming into the cylinder when you rev up the engine.

Conversely, if the spark plug gaps are too big, the spark can get blown out at high speeds. The amount of air and turbulence in the cylinder increases as the speed of the engine increases. And if the gap is too wide, the spark will just get extinguished at high speeds.

You can buy a gapping tool at your local auto parts store for less than $10. And then you’ll have a working car and a new hobby.

But before you even do that, check to make sure that you bought the correct plugs for your car. Using the wrong plugs could also cause this problem. And if there’s any question about whether you’ve got the right plugs, just go to your Chevy dealer’s parts counter and ask them to sell you four new plugs. That’ll at least guarantee that you’re starting with the right parts.

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