Hammer Time
My '99 Ford Ranger makes some disturbing hammering noises, when the conditions are very hot. The noise comes from the engine compartment, but I'm not exactly sure where. A friend who has been in the truck when the noise happened said it reminded him of the old steam radiator in a run-down apartment he rented in New York City. Could I have bad pipes like an old furnace? I'd appreciate any help you can provide.
Lonny Copenhaver
Dallas, Texas

Chances are good that your friend is onto something. The '98-'00 Ford Rangers have reported hammering noises emanating from the engine compartment. The source of the noise has been traced to steam forming in the cooling system. The solution is to see your Ford dealer for a retrofit coolant bypass kit.

Rev Booster
There's something weird going on with the engine idle of my '95 Dodge Dakota pickup. The truck is equipped with the 5.2L V-8 and the manual transmission. When I come to a stop and depress the clutch pedal, the engine revs increase. The same thing happens if I put the transmission in Neutral and keep my foot on the brake. I have power disc brakes, if that matters. Initially, I thought I might have hit the gas pedal as I moved my foot to the brake pedal. I watched very carefully and that wasn't happening. I don't notice this problem when I'm shifting gears without touching the brake pedal. How could using the brakes affect the engine idle? I'm baffled, so I hope you can help. I also have a more minor problem with the engine oil filter. It leaks, although I'm very careful about how I install the filter when I change it. I've even had the oil and filter changed at a franchise oil change shop, and the filter still leaked. I was told not to overtighten the oil filter. Should I tighten the filter beyond normal recommendations?
Derrick Steeb
via e-mail

The brake system could well be the cause of your increased revs. A defective power brake booster can leak vacuum pressure, instead of increasing as it should when the brakes are applied. Engine speed can increase due to extra air bypassing the throttle.

If it's harder to stop your truck than before this problem started, that's a sign of brake booster problems. You can check the effectiveness of the brake booster by applying and holding the brakes down while the engine is idling. Push with normal force. Turn off the engine while maintaining the same pressure on the brakes. If it feels like the brake pedal is rising, you have a brake booster problem. The next step is to have a brake shop professionally check the booster. Another possible source of the increased revs is a defective powertrain control module (PCM). One function of the PCM is to receive signals from the brake pedal switch. A defective signal could tell the air control valve to increase engine speed. You need professional mechanical help if the PCM is at fault.Your leaky oil filter is most likely the result of a warped oil filter adapter plate. Other '95 Dakotas with the 3.9L, 5.0L, and 5.9L engines have reported similar leaks. The simple solution is to get a new adapter plate. Don't overtighten the oil filter. Doing so increases the risk of damaging the filter gasket, which will surely cause a leak.