Cold Start Misfire in Your Car or Truck How to Decarbonize Your Engine

What's up, guys? I'm Andy from 1A Auto. In this video I'm going to show you how to de-carbon the engine or do a top engine clean on this vehicle. This vehicle is running a little rough. It is a direct injection vehicle. What that means is the fuel does not go past the intake valve, so that causes carbon buildup on the intake. Sometimes you get a misfire at a cold start, so what we're going to do is a de-carbon to try to eliminate that problem. If you need any parts for your vehicle, click the link in the description and head over to 1AAuto.com.

So I'm going to take this top engine cleaner and I'm going to clean the tops of the valves. What I need to do is find somewhere in the intake that I can access to be able to spray this in. Right here on this vehicle, I'm going to take the map sensor out. I'll just stick that like that. Then we're going to start the vehicle and let it run.

All right. I'm kind of covering up the hole a little bit so I don't have a vacuum leak. I'm going to spray some of this in there. Now, as I'm spraying this in, it's coating the tops of the intake valves. Okay. So that coated the valves. I'm going to let that sit for a while. There's going to be some of that top engine cleaner on the valves. It's going to soak--let it soak for a couple hours and then come out and start it up.

All right, it's been a couple hours. Now I'm going to start it up. I'm going to hold the throttle up a little bit. It's going to smoke real bad. That's good that it's getting all the carbon out. So I'm just going to hold the RPMs at about 3000 for a little while, just make sure I get all that smoke out.

All right, so now I'm going to take the car for a ride. I'm going to drive it pretty aggressively to get the RPMs up. If it's an automatic transmission, put it down in manual mode and just make sure it shifts pretty high in the RPMs. That'll get it nice and hot and get most of the smoke out of there. After you drive it around aggressively for a while, then it's a good idea to put it back in automatic mode and just drive it normal. Don't be too heavy on the gas, and then when you park it, let it idle for a little bit so that if your vehicle has a turbo that the oil cycles through the turbo, and cools it down and stuff.

When you're out driving in the higher RPMs, just be careful. Don't stay in the high RPMs for very long. Drive it almost like you're driving a manual with a delay shift would be a good idea. So just be careful driving it. You don't want to blow the engine doing that. We are going to add some additive to the fuel tank. This is just a fuel injector cleaner. Put the cap back on. You're going to want to make sure you follow the directions on the cleaner. We're going to go and fill up our tank to make sure our tank is full.

After we perform the de-carbon, we want to make sure we change the oil. Some of that cleaner could've got past the piston rings and could be in the crankcase, so we want to get that out. So after we let it cool down, we brought it in. We're going to change the oil, and then we'll be good to go.

Thanks for watching. Visit 1AAuto.com for quality auto parts shipped to your door, the place for DIY auto repair. And if you enjoyed this video, please click the subscribe button.