CLICK & CLACK : A Necessary Adjustment

Sunday, March 1, 2009

Dear Tom and Ray:

I have a 2002 Dodge Ram with 130,000 miles. It's primarily used as a commuter truck -- with a little bit of horse and hay hauling. The dealership recommended a 100,000-mile valve adjustment as routine maintenance. I'm meticulous about maintenance, but I'm reluctant to interfere with an engine that works well. -- Jeri

TOM: Jeri, we strongly recommend regular maintenance even when nothing is obviously wrong.

RAY: And with 130,000 miles, you're overdue. If your valves are out of adjustment, the engine can run less efficiently, because the valves aren't opening as far as they should. That decreases your performance and fuel economy.

TOM: Unadjusted valves also shorten the life of your engine. If there's slop in the valve train, components like the camshaft and lifters will bang against one another and wear out sooner.

RAY: And the final reason to do the adjustment is that properly adjusted valves make the engine run quieter.

Dear Tom and Ray:

I have a 2002 Hyundai Elantra with 97,000 miles. During a state inspection recently, the mechanic told me that I will soon need to replace my timing chain. My son worked as an apprentice auto mechanic in a former life and has taken helicopter-engine repair in the military. He does all his own work on his Jeeps. He feels that he can do this job for me, and told me to buy the repair manual. Should I let my son do this? And how long would my car be "in the shop" if I let him do this? -- Arlene

RAY: Well, your car doesn't have a timing chain, it has a timing belt. And that's unfortunate, because a timing chain -- which is supposed to last the life of the engine -- would have been covered by your 10-year, 100,000-mile warranty.

TOM: The belt, on the other hand, was supposed to be changed at 60,000 miles by you, as part of your regular maintenance. And if you neglected to change it back then, you can't reasonably expect Hyundai to cover its failure at 97,000 miles.

RAY: There are two reasons why you might not want your son to tackle this. First, the parts for this job are relatively expensive, and there's at least one special tool (a puller) he may need to buy to remove the camshaft pulley. So even if you get the labor for free, this job is still going to cost you several hundred dollars.

TOM: But more importantly, because of the nature of this repair, there's a risk of catastrophic failure if he happens to do it wrong. So, in the worst-case scenario, you save $300, but he bends all of the valves, and it costs you $3,000 to rebuild the engine so you can drive the car.

RAY: Bite the bullet and have the dealer (or an independent, professional mechanic, who will be cheaper -- but will still guarantee the work) do the timing belt.

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Copyright 2007 by Tom and Ray Magliozzi and Doug Berman

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