How To Test The Linear EGR Valve (1996 2.2L Buick Century, Oldsmobile Cutlass Ciera)

TEST 6: EGR Solenoid Resistance Test

In this test section, you'll check the EGR valve solenoid's resistance with your multimeter in Ohms mode.

NOTE: This test is performed on the male terminals of the EGR valve itself.

IMPORTANT: The EGR valve has to be at ambient temperature to get an accurate test result. If the EGR valve is hot, let it cool down completely.

These are the test steps:

1. 1

   Place your multimeter in Ohms mode.

2. 2

   Disconnect the EGR valve from its pigtail connector.

3. 3

   Connect the red multimeter test lead to the male terminal labeled with the letter A.

4. 4

   Connect the black multimeter test lead to terminal labeled with the letter E.

5. 5

   The multimeter should read 8 to 9 Ohms.

Let's interpret your test results:

CASE 1: The multimeter registered the indicated Ohms value. This is the correct and expected test result.

Your next step is to remove the EGR valve and check for carbon build up on the EGR valve and EGR valve adapter block. Go to: TEST 7: Checking For Carbon Build Up.

CASE 2: The multimeter DID NOT register the indicated Ohms value. This test result confirms the EGR valve is bad. Replace the EGR valve.

TEST 7: Checking For Carbon Build Up

As you drive the vehicle, the engine releases quite a bit of black soot (from its combustion process) into its exhaust.

This black soot will eventually collect in the EGR valve system passages and harden into carbon buildup.

Eventually, this carbon buildup will cause the EGR valve's pintle to become stuck 'open' or 'closed'.

This buildup of carbon particles will also clog the intake manifold EGR passages. It doesn't happen overnight but will happen.

So your next step is to remove the EGR valve and inspect for carbon buildup blocking the pintle and/or clogging its two orifices.

You'll also check that the EGR valve adapter block's orifices are not clogged with carbon buildup.

These are the test steps:

1. 1

   Remove the EGR valve from its place on the engine.

2. 2

   Check that the EGR valve pintle is not held open carbon build up.

3. 3

   Check the orifices in the EGR valve adapter for carbon build up and carbon blockage.

Let's interpret your test results:

CASE 1: The EGR pintle and EGR adapter block orifices ARE NOT blocked with carbon. This is the correct test result.

All of the tests you've performed up to this point have not found any problems with the EGR valve. I suggest one last test. Go to: TEST 8: Checking For Clogged EGR Passages In The Intake Manifold.

CASE 2: Both the EGR pintle and EGR base orifices are blocked with carbon. Your next step is to remove the carbon deposits.

Once the carbon has been removed, verify the EGR pintle can completely close on its seat.

Re-install the EGR valve, clear the EGR valve fault codes (that were lighting up the check engine light) and road test the vehicle to see if the problem is solved.

CASE 3: Only the EGR pintle was blocked with pieces of carbon from fully closing on its seat. This condition allows exhaust gas to enter the intake manifold at all times, causing a rough idle and/or engine stall problem.

Remove the carbon blocking the EGR pintle. Re-install the EGR valve, clear the EGR valve fault codes (that were lighting up the check engine light), and road test the vehicle to see if the problem is solved.

CASE 4: Only the EGR Base orifices were blocked/closed off with carbon. This blockage will not allow the flow of exhaust gas into the intake manifold.

Your next step is to clean/remove the carbon. Re-install the EGR valve, clear the EGR valve fault codes (that were lighting up the check engine light [CEL]), and road test the vehicle to see if the problem is solved.

TEST 8: Checking For Clogged EGR Passages In The Intake Manifold

So far, all your tests haven't found any problems with the EGR valve, yet an EGR system diagnostic trouble code lit up the check engine light.

There's a good chance that the EGR flow passages (which are not visible) in the intake manifold are clogged (blocked) with carbon buildup.

You can check for this condition with a particular test: starting the engine with the EGR valve removed from its place (on the EGR adapter block).

These are the test steps:

1. 1

   Remove the EGR valve from its place on the engine.

2. 2

   Start the engine.

3. 3

   You'll notice one of two things:
   
   1.) The engine will start and run smoothly (as if the EGR valve where still there in its place).
   
   2.) The engine will start and idle extremely high and/or stall immediately.

4. 4

   If the engine starts and idles very very high, have your helper immediately turn off the engine.

Let's interpret your test results:

CASE 1: The engine started and idled smooth. Then this confirms beyond a shadow of a doubt the EGR passages are clogged inside the intake manifold.

You'll need to remove the intake manifold to remove this carbon build up blocking the EGR passages.

CASE 2: The engine started and idled very high and/or stalled. Then this confirms that the EGR passages inside the plenum ARE NOT clogged.

More 2.2L Buick Century And Oldsmobile Cutlass Ciera Test Tutorials

If this tutorial was helpful, be sure and take a look at all of the 2.2L Buick Century and Oldsmobile Cutlass Ciera diagnostic tutorials in this index:

• GM 2.2L Index Of Articles.

Here's a sample of the tutorials you'll find there:

• How To Test The Fuel Pump (1993-1996 2.2L Buick Century, Oldsmobile Cutlass Ciera).
• How To Test The TPS (1993-1996 2.2L Buick Century, Oldsmobile Cutlass Ciera).
• How To Test The EGR Valve (1993-1995 2.2L Buick Century, Oldsmobile Cutlass Ciera).
• How To Test The MAP Sensor (1993-1996 2.2L Buick Century, Oldsmobile Cutlass Ciera).