Is Toyota’s D-4S Self-Cleaning Feature A Big Deal?
Now that the 2016 Toyota Tacoma is hitting dealer lots, we wonder how many new owners are asking about the whistling noise when idling and turning off the truck? Confused yourself? Stay with us.The noise, found in all 2016 Toyota Tacoma trucks, is the new D-4S technology burning off carbon buildup through engine usage. It resembles more of a slight whistling noise similar to air injector cleaning sound found in Tundra pickups.
“What we’re doing is we have a slit on the side of our injector and we’re blowing that carbon off,” Mike Sweers, Toyota Tacoma’s chief engineer, told WardsAuto. “If we tried to use just high pressure, using just the nozzle itself, you would clean the bottom of that nozzle.
“But since the carbon grows from the outside and comes around, you would still plug up that injector,” he adds. “So by cleaning on the outside of that, we get a clean injector all the time.”
This process occurs during a hot idle or when the engine is turned off.
“When you go into a hot-idle situation, the system is going to look at the time that it ran, the number of cycles the injectors went through, the temperature of the injectors and then it goes into a self-cleaning mode,” Sweers says. “Because we have the port injection, I can continue idling the engine without having any side effects.”
Essentially, it is the same idea behind a self-cleaning oven, yet there are no additives.This technology has been used in various Toyota products over the years like the 2005 Lexus GS 350, 2006 Lexus IS 350 and the current generation of both of those products as well as the RC and Scion FR-S sports car according to WardsAuto.
The sound is so subtle, I had to stick my ear on the hood to pick it up and actively listen for it while sitting at a stop light.
What’s the Big Deal?
Great, the Toyota Tacoma makes a “noise,” you say. Well, it is a bit more complex than that. Carbon buildup is a big problem for engines and is compounded by short trips. You hear about this problem when your engine runs ragged and typically the advice is to hit the interstate for a while to burn off the carbon deposits.
Another part of this puzzle has to do advanced engine designs like the EcoBoost. While the rumors of excessive carbon buildup haven’t proved true, carbon buildup does occur. In 2011, Ford tore down a “tortured” EcoBoost engine at the North American International Auto Show as part of a demonstration. That engine showed signs of carbon buildup on the valves according to the Pickuptrucks.com story. This was especially interesting since the truck was run at high speeds and used under duress on many occasions leading one to think the engine temperatures were high enough to burn the carbon off.
Now, it is worth noting, the EcoBoost engine still performed and the carbon buildup wasn’t an issue. Yet, long-term build up of carbon can reduce engine performance and this is why the D-4S technology is now in the Tacoma.
Lastly, another issue Toyota’s D-4S technology aims to solve is differences in fuel quality. Most diesel owners know the differences in quality makes a big difference in power and fuel economy. Poor fuel quality can also leave all sorts of chemicals in the valves. Toyota’s self-cleaning feature burns out these impurities.
What do you think? Is this a big deal or just a “car nerd” topic?
Filed Under: Auto News