How To Test The Ford Escape COP Coils (Troubleshooting A Misfire)

Testing the COP coils in your 3.0L Ford Escape (or 3.0L Mazda Tribute) can be a challenge, since three of them are under the intake manifold plenum (this article can be applied to several other 3.0 Ford models).

The three that are underneath the intake plenum are the COP coils for cylinders #1, #2 and #3 (cylinder #1 is the one closest to the serpentine belt).

These three can not be easily tested like the ones that are on the engine bank that is closest to the radiator.

Well, in this article, I'm gonna' offer you a comprehensive testing strategy that'll help you get to the bottom of the misfire on your 3.0L Ford Escape or 3.0L Mazda Tribute.

You can find this tutorial in Spanish here: Cómo Probar Las Bobinas De Encendido (3.0L Ford Escape) (at: autotecnico-online.com).

Important Tips And Suggestions

TIP 1: Although the main focus of this article is testing the COP coils on a 3.0L Ford Escape (3.0L Mazda Tribute), the tests apply to the vehicles listed in the 'Applies To' box on the second column (since these vehicles also have the COP coils for cylinders #1, #2, and #3 underneath a plastic intake manifold plenum).

TIP 2: The fuel pump relay needs to be removed before testing the COP coils for spark. This is a safety precaution that will prevent the engine from starting.

The photo of the fuel pump relay (in the fuse box) in this article is of a Ford Escape (Mazda Tribute). You can see this photo here: Location Of The Fuel Pump Relay. If your vehicle is not a Ford Escape, you'll need to consult your owner's manual or a repair manual for the location of the fuel pump relay on your specific vehicle.

TIP 3: Testing the COP coils on your Ford Escape may require removing the top part of the intake manifold (known as the intake manifold plenum).

TIP 4: When removing the plastic intake manifold plenum, you've got to be extra careful nothing falls into the open intake manifold ports.

Once the plenum is off the intake manifold, stuff clean rags into the 6 open ports to prevent any foreign object (like a bolt) from falling inside.

Symptoms Of A Bad Ford Escape COP Coil

The most common symptom of a bad COP ignition coil on your Ford Escape is a misfire condition. What 'throws a wrench into the works', is that the misfire condition sometimes doesn't set a diagnostic trouble code (DTC).

You may also see one or more of the following symptoms:

1. Check engine light is on with one or several of the following DTCs :
   • P0300: Random Cylinder Misfire.
   • P0301: Cylinder #1 Misfire.
   • P0302: Cylinder #2 Misfire.
   • P0303: Cylinder #3 Misfire.
   • P0304: Cylinder #4 Misfire.
   • P0305: Cylinder #5 Misfire.
   • P0306: Cylinder #6 Misfire.
2. Rough idle.
3. Bad gas mileage.
4. Excessive tail-pipe emissions (pollution).
5. A "rotten egg" smell coming from the tailpipe.
   • This smell is caused by unburned gasoline from the misfiring cylinder overloading the catalytic converter's oxidation process.
6. Engine misfires under load. In other words; the engine starts to miss as you give it gas.

What Tools Do I Need To Test The Ford Escape COP Coils?

You'll test and diagnose the ignition coils on the car or truck with some very basic tools. You'll need:

1. A 12 Volt automotive test light.
2. A multimeter.
3. An HEI spark tester.
   • This inexpensive spark tester is a MUST have tool to be able to correctly diagnose the ignition coil pack on your Ford (or Mercury or Mazda) vehicle with the info/tests in this article (don't have an HEI spark tester? Need to buy one? You can buy it here: OTC 6589 Electronic Ignition Spark Tester).
4. You'll need a helper to help you crank the engine while you perform the tests.
5. A repair manual.
   • For any remove and replace info that I don't cover in this article.

A scan tool will come in handy to read any misfire diagnostic trouble codes stored in your Ford Escape's PCM's memory but to test the actual COP coils -You DO NOT need a scan tool.

What Causes My Ford Escape To Misfire?

Over the years, I've identified 3 major issues that are usually the root cause of a misfire condition on a 3.0L Ford Escape (Mazda Tribute) and more than likely your Ford Escape (Mazda Tribute) is experiencing one of them. They are:

1. A bad ignition coil.
   • The coil just stops sparking due to age.
   • A bad COP coil will definitely set a misfire diagnostic trouble code.
   • This is usually the easiest issue to diagnose and resolve.
2. Oil leaking into the spark plug tubes from the valve cover gaskets.
   • The COP coil and spark plugs are centered in the middle of the valve cover gasket and the valve cover gasket is the one tasked with keeping oil from leaking into the spark plug tubes.
3. Intake manifold gasket leaking vacuum.
   • This usually causes a P0300 random misfire code.
   • Ford, in its infinite wisdom, decided to use plastic and rubber gaskets for the intake manifold and the intake manifold plenum on your Ford Escape (Mazda Tribute).
   • Over time, these harden and become compressed to the point that they stop sealing.
   • When this happens, you'll experience a rough idle condition at engine start up, but once the engine warms up (and the gaskets warm up, loosen up and expand), the problem goes away.

Where Do I Start My Misfire Troubleshooting Tests?

You're mission (and the purpose of this article) is to find out if the misfire code is due to a lack of spark in a specific engine cylinder. It's as simple as that. As mentioned before, what complicates this a bit, is the fact that 3 of 6 COP coils are under the plastic intake manifold plenum.

So what's the first thing you should do to start troubleshooting a misfire on your 3.0L Ford Escape (3.0L Mazda Tribute)? It's to check for misfire trouble codes with a scan tool.

If you're fortunate enough, your Escape will have a misfire code to let you know exactly which engine cylinder is the one missing. If your 3.0L Ford Escape (Mazda Tribute) doesn't have any misfire diagnostic trouble codes, don't worry, this tutorial will still help.

OK, to get this show on the road, choose from one of the following:

• TEST 1: I Have A Misfire Code Or Codes.
• TEST 2: I Have No Misfire Codes (or a P0300).

TEST 1: I Have A Misfire Code Or Codes

If you have a misfire code or misfire codes, half the battle is over.

What you now need to do is to use the image on the right to ID the cylinder that's being accused of misfiring.

With this information, you'll be able to see find out if the misfiring cylinder is on the bank that's underneath the intake manifold's plastic plenum or not.

• P0301 accuses cylinder #1 (under plenum).
• P0302 accuses cylinder #2 (under plenum).
• P0303 accuses cylinder #3 (under plenum).
• P0304 accuses cylinder #4.
• P0305 accuses cylinder #5.
• P0306 accuses cylinder #6.

If the misfiring cylinder (identified by the misfire code) is underneath the plastic plenum (these would be cylinders #1, #2 and #3), you're looking at having to remove the plenum to check for the exact cause of the problem.

If you have a P0300 (Random Misfire) code, then you need to treat this as NOT having a misfire code and your starting point is here: TEST 2: I Have No Misfire Codes.

CASE 1: The misfiring cylinder is underneath the plenum. This means that you have one of the following DTCs P0301, P0302, or P0303. Go to: TEST 5: Misfiring COP Coil Under Plenum.

CASE 2: The misfiring cylinder is NOT underneath the plenum. This means that you have one of the following DTCs P0304, P0305, or P0306. Go to: TEST 6: Misfiring COP Coil In Front Engine Bank.

TEST 2: I Have No Misfire Codes (or a P0300)

If you don't have misfire codes stored in the PCM's memory or if you have a P0300 Random Misfire Code, then you're gonna' have to do some exploratory surgery and check for these specific things:

1. Is engine oil leaking from the valve cover into the spark plug tubes?
2. Is the plenum gasket (which is made of rubber) leaking?
3. Are the COP coil sparking or Not?

This is gonna' involve removing the intake manifold plenum to get to the three coil-on-plug ignition coils that are in the back of the engine but before you do, I recommend that you test the front COP coils for spark with a spark tester.

I want to emphasize that testing the front COP coils for spark needs to be done before you remove the plenum (to get to the ones in the back). Why? Here are the two main reasons:

1. The COP coils for cylinders #4, #5, and #6 need to be cleared of being bad right off the bat.
2. You'll also find out if the front valve cover is leaking oil onto the spark plug tubes because if it is, then the rear valve cover will also be leaking oil into the spark plugs.

OK, let's get started with the very first test in the next page. Go to: TEST 3: Testing Cylinders #4, #5, #6 For Spark.