Rebates, Rebates, Rebates!

Autolite, Monroe and Raybestos all have rebates ending soon. Take advantage of these rebates while there is still time!

• Autolite - Get up to $32 back on select Autolite spark plugs
• Monroe - Get up to $120 back with purchase of qualifying Monroe shocks and struts
• Raybestos - Get up to $50 back with purchase of qualifying Raybestos brakes

To see the details for these rebates, or to look at the other rebates currently being offered by Anco, ACDelco, Bosch, Champion, Dynomax/Walker, Fram, Omix-Ada/Rugged Ridge, Rancho and Wagner go to the Promotions and Rebates page.

While shopping, watch for the yellow "Promotion/Rebate" star next to the part names to help you save even more on RockAuto’s reliably low prices!

Dorman Impact Sensors

Dorman impact sensors, also known as air bag sensors, are an essential safety item and have recently been added to the RockAuto catalog. The impact sensor is responsible for discerning sudden vehicle deceleration, and communicating that information to the safety restraint systems module (SRS). The SRS uses that data, plus additional information from a variety of other systems, in determining airbag deployment.

Impact sensors are mounted behind the front bumper leaving them exposed to moisture and temperature fluctuations. As a result, one of the most common reasons for failure is corrosion.

With plug-and-play installation, Dorman impact sensors are a reliable, low-cost, do-it-yourself repair when the air bag warning light has been triggered. To help you along with the install, a manufacturer video outlining the installation process is featured on the "Info" page for these parts. Find impact sensors in the "Body-Exterior" category of the RockAuto catalog. Dorman impact sensors are currently primarily available for Chevrolet and GMC trucks and SUVs.

Wiper Contest!

The $4, $3, $2, $1 Wiper Wholesaler Closeout is still going strong! Enjoy the extreme savings and have fun submitting your creative entries for the Wiper Contest:

Premium wipers make great gifts for graduations, weddings, Sweet Sixteens, dinner parties, jury duty, or to welcome new neighbors. Use them as pedestrian bridges on your model train layout or to replace your broken ceiling fan blade. Possibilities are endless and, to encourage creative thinking, we're offering RockAuto T-Shirts and RockAuto Hats for the most creative non-traditional wiper blade uses. Send a picture and description to marketing@rockauto.com by April 30th and we'll feature some of our favorites in our May newsletters.

Forum of the Month

FourEyedPride offers a tight-knit, friendly, helpful community that shares your enthusiasm for 1979-1986 Mustangs, Capris and SVOs. We currently have two ways of interacting with your fellow FourEyed Fans: an active message board and a chat room.

Our message board is the best place for technical help, planning get-togethers with others in your area, and showing off your ride. Our chat room is for casual conversation and getting to know one another in a real-time environment.

Browse the message board and join the chat room today!

If you are the administrator or member of a forum and you would like to see your website featured in an upcoming newsletter and receive a discount code to share with your members, contact cynthia@rockauto.com.

Repair Mistakes & Blunders

It was a beautiful spring day in 1972; I was 16 and cruising around with my girlfriends in my green 1971 Cutlass Supreme when we happened upon a group of cute high school boys hanging out on a corner with all their cool cars. They flagged us down and we talked for about an hour. 

Before we pulled away, one of the more entertaining boys in the group says to me casually, “Did you get the winter air taken out of your tires yet?” “Uh, no,” I said. "Do I have to do that?" “Of course you do” He said … "You should change the air every season…you need to get the spring air in those tires fast or they could explode. There’s a gas station right down the street - my brother’s working there now. Just go in and ask Pete to take out the winter air and put in the spring air. He probably won’t even charge you.” 

Alarmed that my tires were going to explode, I immediately pulled into the gas station down the road. Back in those days, the guys pumped your gas, checked your oil, washed your windshield and obligingly put air in your tires for free. I went inside the garage where five mechanics were working on cars and a few other guys were just hanging around talking. I found Pete and made my request. 

Why was everyone laughing? This was a serious matter! I still remember that horrifying moment when I realized I’d been "punked" by a band of morons. I was pretty sure those morons were still laughing back there on the corner.

Needless to say, my green Cutlass and I became a legend in that neighborhood. And, oh yeah, I married one of those morons!

Kathy in Illinois

Editor's Note: "Was this winter vs. spring air controversy a precursor to the free air vs. nitrogen air in tires question we face now?"

Tell us about your most infamous auto repair blunder or unconventional fix. Use your woe to help others avoid similar mistakes or share off-the-wall solutions that worked (at least for a while!). Please e-mail your story to flamur@rockauto.com. Include your mailing address and if you would like a RockAuto T-Shirt (please let us know your shirt size) or Hat if we publish your story. See the T-Shirts and Hats under Tools & Universal Parts in the catalog. The story will be credited using only your first name and your vague geographic location (state, province, country, continent, etc.) so you can remain semi-anonymous!

Automotive Trivia

What car brand name can be read from aircraft or perhaps even spacecraft traveling above Indiana?

A. Studebaker
B. Subaru
C. Toyota

Answer below

Need to Blow the Gunk Out

Gasoline direct injection (GDI) is becoming more common as new car manufacturers work to wring more power and better gas mileage out of smaller engines. Carbon and other deposits quickly collecting on intake valves and interfering with their operation has been a problem on some GDI engines. The problem was a surprise to me. Its causes are actually quite simple while the solutions vary and are complex.

Old style, port fuel injectors spray gasoline into the intake manifold runners at around 75 psi (500 kPa) or less. The gasoline and air are drawn into the combustion chamber when the intake valve opens. GDI injectors are mounted in the cylinder head much like a spark plug and they spray the gasoline directly into the combustion chamber. They must deliver the gasoline at extremely high pressure, typically around 3000 psi (21,000 kPa), to overcome high in-cylinder pressures and to deliver fuel vapor in a precise, short time period. For perspective, 3000 psi is the maximum pressure generated by a typical pressure washer or the pressure of the compressed air in a high-powered air rifle.

With port fuel injection, the gasoline and its detergents wash off the back side of the intake valve every time the gasoline enters the combustion chamber. GDI injectors send gasoline blasting into the combustion chamber at pressures that could easily take chewing gum off a sidewalk, but the gasoline often does not reach the back side of the intake valve. Carbon, oil and other residues can build up on the intake valve. The valve does not seat properly leading to problems with engine performance, emissions and durability.

Dirty intake valves are more of a problem on some GDI engines compared to others because engine and fuel system design is the primary factor. Using gasoline without enough added detergents and too many short trips around town are a couple of other suggested causes, but to me they just indicate the need for a better fuel system design. It does not matter how much detergent is in the gasoline if the gasoline never reaches the back of the intake valve. I personally like the idea of needing to frequently take cars for long drives at high speeds, but unfortunately, my spouse (and police officers) long ago stopped believing my “need to blow the gunk out” excuse.

Car manufacturers have different, sometimes almost contradictory, theories on how to prevent carbon buildup on intake valves in GDI engines. Some try to leave the intake valves open slightly longer to allow gasoline to reach and cleanse the back of the intake valve. Some think it is better to keep the gasoline off of the valve so soot does not build up on the valve face. Some car manufacturers are creating GDI / port fuel injection hybrids by adding a fuel injector back to the intake manifold to guarantee there is always a little gasoline keeping the intake valves clean. There is likely more than one good solution because there are many fuel system, cylinder head, valve train, fuel injector, etc. designs.

Time and miles tell which GDI engines have the fewest problems with dirty intake valves. A car manufacturer might declare success if an engine does not need the cylinder head removed and the intake valves scraped clean during the warranty period, but the car owner likely never wants to remove the cylinder head. Maintaining the crankcase ventilation system (PCV valve, etc.) and the exhaust gas recirculation (EGR valve, etc.) systems on GDI engines is more important than ever because they are another possible source of oily residue and carbon that could collect on intake valves. With spring approaching, even carbureted and port fuel injected cars might benefit from a tank full of fresh, detergent gasoline and a good intake-valve-cleansing, blow-the-gunk-out drive (while observing the posted speed limit of course)!

Tom Taylor,
RockAuto.com

This is my vintage 1979 GL 1600 Subaru wagon I purchased 12 years ago. She was owned originally by a family in Prescott, AZ. The vehicle then found its way to the grandkids here in Flagstaff. I purchased the vehicle when my wife’s vehicle was in an accident. I have been doing work on this vehicle ever since. I have had extensive work done on the body and transmission. She’s old, but she's a solid performer and I think a true classic! The car has only 148,000 miles and is all Subaru original aside from a stereo that was added prior to my acquisition.

I just started buying parts from RockAuto recently. Brake rotors from RockAuto replaced the factory originals since the dealership - and the local auto parts store - could not find any that would fit. Finding parts for this vehicle had become a challenge, but RockAuto has many of the parts I need that match OEM specifications.

Dan in Arizona

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