You know you hear it. Rattle, rattle, ping. Rattle, rattle, ping. Before you head to the mechanic oblivious to what's going on under the hood, check out http://www.mechanicnet.com. The site's got easy-to-use tools to help diagnose the problem and estimate the cost.
It also keeps track of maintenance and sends automatic service reminders. And if you aren't sure where to take your four-wheeled baby, you can research nearby shops.
Yahoo offers similar features on http://autos.yahoo.com/maintain.html. If you assess your car by intuition more than by dipstick, there's help here. You can personalize the site to list mileage (which you input), when you're due for an oil change and recalls and news related to the vehicle make and model you list. The site can send an e-mail reminder and insert the service date on the Yahoo calendar.
Many sites have maintenance log features, including http://www.cardogz.com/log/AutoMaintLog.mv, http://www.pennzoil.com/carcare/autotracker/register.asp and http://www.carcarecity.com.
Check out iCARumba (http://www.icarumba.com/info/auto-maintenance.htm) for free information about repair and maintenance as well as a diagnostic tool, Dr.CARumba.
You can get a smattering of information on just about every automotive issue at http://www.autoshop-online.com. Autoshop Online's Automotive 101 index covers every system in the vehicle, from anti-lock brakes and air conditioning to steering and suspension.
The site also offers tips on finding a shop, such as looking for one before your SUV's hooked up to a tow truck. Ask friends for recommendations and check for certification.
At http://www.ownersite.com, you can generate e-mail or on-screen reminders for more than 70 service procedures, as well as warranty, insurance, registration and driver's license expiration. It's free for as many as two vehicles.
EHow's automotive center (http://www.ehow.com/Center/catIndex/0,1004,1005,00.html) walks weekend mechanics through all kinds of fluid replacement and minor maintenance techniques. At AutoSite (http://www.autosite.com/garage/garmenu.asp), you can find maintenance checklists, an illustrated repair guide and an encyclopedia.
At http://www.10w40.com, you'll find links to sites for auto repair, enthusiasts and service providers. The site also offers shop referrals and schedules appointments. The site builds a list of shops, including a description of amenities and certifications, based on the make and model of the vehicle, the region and the services sought.
Signature's Nationwide Auto Club lists National Institute for Automotive Service Excellence-certified shops and will map the nearest ones for you at http://www.autoclub.com/index.asp?page=maint1. The site also offers a free hotline that gives answers to repair questions and free advice.
Maybe you're just running on empty. Although gas prices appear to be dropping, Southern Californians might need even more savings to offset higher electricity bills. Several sites can help you strategize before hitting the pump. In addition to the general information sites such as http://www.gaspricewatch.com, http://www.oilprices.com and http://www.cheap-fuel.com, there are some with region-specific prices.
Angelenos can check out http://www.losangelesgasprices.com, Inland Emperors can click on http://www.geocities.com/gasprices_inland_empire and San Diegans can go to http://www.sandiegogasprices.com or http://www.fueltracker.com.
Michelle Maltais is a broadcast producer and copy editor at The Times.