Dear Car Talk:

I'm hearing a clicking or tapping noise from my 2010 Honda Pilot. It has 110,000 miles on it. The valves have never been adjusted, nor has the timing belt been replaced (I know it's time).

I'm reading and hearing all sorts of comments that when the valves get noisy, they are in need of adjustment. But I have also heard that when valves get tight, that is when they need adjustment.

Two part question: Which of the above explanations is right and why, and how much should I pay for a valve adjustment? Thank you for your help! -- Gordon



They're both right, and since this is a V6 engine, it could easily cost you $400-$500 to have the valves adjusted. That'll include new valve cover gaskets.

You could be cheap and try to put the valve covers back on using the old gaskets, but that's kind of like taking a shower and then not bothering to change your underwear.

We've found that Hondas do require regular valve adjustments. Honda recommends it every 105,000 miles, when you change the timing belt. But we recommend our customers check their valves every 75,000 miles.

Here's why: Honda valves have a unique propensity to get too tight over time, and if valves get too tight, you don't hear anything.

But valves that are too tight won't close all the way, and if they remain open during the combustion process, hot gasses will blow past the valves and eventually melt them. Pretty soon, you'll have a five cylinder Pilot. Then a four cylinder Pilot, etc.

If you think a valve adjustment is expensive, just wait until you need 24 valve replacements. That's thousands of dollars.

Having valves that are too loose is a problem, too. But at least with loose valves, you get a warning -- a clattering noise -- if you pay attention to such things.

Now, it's possible for some of your valves to be too loose (that's when they make noise) and some of your valves to be too tight (when they don't make noise, but they're even more apt to be damaged).

So, you should go to a mechanic who knows Honda engines. At the very least, let your regular mechanic know that you understand that Honda valves sometimes get too tight, and you want to be sure he checks for tight valves as well as loose valves.

Those tight valves are what the kids call silent but deadly, Gordon. Get it done soon.