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2.0T Borescoping the 2.0 intake valves

Discussion in 'Engine, Drivetrain, and Exhaust Discussion' started by StingEm, May 17, 2018.

  1. StingEm

    StingEm United States Active Member

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    All GDI engines without additional port injection are known to form carbon buildup on the intake valves. The rate of carbon deposit formation depends on a lot of factors including: engine design, oil properties, oil change intervals, fuel quality, operating conditions (aggressiveness and highway vs. city), additional preventative measures, and more.

    My goal is to monitor deposit formation using a borescope as the miles begin to accumulate on the engine. This will also allow me to judge how well the preventative measures I will be taking are working.

    Unfortunately the 2.0L engine is being a bit annoying when it comes to viewing the valves. There is a great entry spot into the manifold through the manifold pressure / intake air temp combo sensor shown here:

    MAP_IAT_Sensor.JPG

    Removal of the MAP/IAT sensor is quick and easy. Just disconnect the electrical connector, remove the two 10mm bolts, and then pull the sensor straight up with a slight twisting motion (it has an o-ring seal). The sensor hole will fit a common 8.5mm diameter or smaller borescope.

    One thing to note is that the engine will need to sit with the hood up for a few hours after shutting it down in order for it to cool off completely. Attempting to borescope the intake while hot will result in the camera sensor overheating and washing out the picture.

    Once you are inside and moving forward towards the cylinder head is where you will find the annoyance. The 2.0L engine has a Variable Charge Motion Actuator that controls a flapper mechanism which pops up in front of the cylinder intake ports when the engine is operating at less than 2700rpm. The VCMA mechanism is spring loaded and sits in the up (obstructed) position when the VCMA motor is powered off. You can see the VCM actuator rod on the backside of the intake manifold, and you can easily move the white crank arm up using something hooked (I used a tent stake). Unfortunately it’s a bit difficult to keep the tool hooked on once it pivots into the upper position. I think something like bailing wire would need to be looped around the little white crank arm in order to hold it up while attempting to borescope the valves. It might be a two person job depending on how you rig it up.

    VCMA_overview.JPG VCMA_side-view.JPG VCMA_operation.JPG

    The dealer service tool would make this a lot easier since the service manual shows that they can manually actuate the VCMA. I also looked at the schematics and while it seems like voltage could be manually applied to the DC motor the reality is that the electrical connector is not easy to access.

    I used a small/cheap 5.5mm USB borescope to try and get over the top of the flap but didn’t have much luck. I could just barely see the curve in the heads where the flow separates into the two individual valves, but I could not see the valves themselves.

    I have decided to revisit this borescoping process once the engine reaches 5k-10k miles when there might actually be something worth the trouble of observing.

    Here’s a link showing a similar process on an ecoboost engine:

    This thread is where I will be discussing my oil choices and preventative measures:
     
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