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George H.
George H., ASE Certified Technician
Category: Cadillac
Satisfied Customers: 18270
Experience:  ASE Master Tech 15+ Years
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1996 cadillac deville: EGR Valve..000 miles..sticking..check engine

Resolved Question:

Replacing EGR Valve on 1996 Cadillace Deville:

I have a 1996 Deville with 4.6 Northstar engine and less than 70,000 miles. The EGR valve is sticking and I am getting a check engine message. My mechnic has confirmed the piston in the valve has seized up with carbon and is not opening and closing properly. Mechanic wants $300+ for valve plus labor. I can buy a new replacement valve for much less. Replacing valve does not look too difficult. What do I need to do to make sure I get correct replacement valve? Is it necessary to disconnect battery when replacing valve, Is it necessary to release pressure on gas lines when doing so, and if so how is pressure released? What type of tool is required to loosen the nut on front side of valve that holds the gas lines. After removing valve, should I first try cleaning valve with carburater cleaner or just replace it?
Submitted: 6 years ago.
Category: Cadillac
Expert:  George H. replied 6 years ago.

Hello I will help you with your question,


Just to make sure we are talking about the same part look at this diagram. There are no fuel lines that I am aware of to change this valve but it might be possible to install it backwards so check the orientation of the original.




The nut for the lines is a 10 mm nut but that is on the front of the engine I believe


Here is the service information to change the valve


Removal Procedure

  1. Disconnect the electrical connector from the solenoid.
  2. Remove the two mounting bolts from the base of the EGR valve.
  3. Remove the EGR Valve.
    • Inspect the EGR passages in the crossover water pump housing for deposits.
    • Clean the EGR passages as needed.
  1. Clean the mounting surface for the EGR valve.

Installation Procedure

  1. Install cleaned or replacement EGR valve using a new gasket.
  2. Install the two mounting bolts at base of EGR valve. Tighten the 2 mounting bolts to 24 Nm (18 lb ft).
  3. Connect the electrical connector to EGR solenoid


You can try cleaning the valve first, its worth a shot


EGR Valve Cleaning
Whenever the EGR valve is removed, or during regularly scheduled EGR system maintenance, the EGR system should be inspected and cleaned. This will insure that the EGR system will function properly under all operating conditions. Proper EGR system service consists of the five steps listed below:

Caution: When removing components for cleaning, avoid breathing fumes and swallowing EGR exhaust deposits as bodily injury may result.

EGR System Service

  1. EGR System Diagnosis. Diagnosis of the EGR system should be performed if required by engine performance or engine driveability symptoms and no PCM DTCs are set.
  2. EGR Valve Pipe Cleaning and checking for leaks. Clean and check the EGR pipe from the exhaust manifold to the EGR valve and the EGR pipe from the water pump crossover to the throttle body spacer.
  3. EGR Valve Cleaning. If the EGR system is operating correctly, the EGR valve can be removed, checked for deposits, cleaned, and replaced. Use the procedure below for this operation.

3.1.Remove the EGR valve from the engine.
3.2.While holding the EGR valve in your hand, using a pencil eraser or other suitable soft instrument to depress the pintle several times. The pintle should move in and out smoothly, replace any valve that exhibits tendencies to stick.
3.3.While holding the EGR valve base in your hand, try to rotate the connector housing. Repeat for the coil housing. Replace any valve that exhibits looseness.
3.4.Inspect the EGR valve pintle and seat for deposits. Use a cloth or other suitable soft device to remove deposits. Remove all loose particles. If deposits are such that pintle/base interface can't be cleaned adequately to allow pintle to seal against the seat, replace the valve. Damage to the powdered metal EGR valve base will occur if cleaned with solvents, sharp tools, wire brush/wheel or sand blasting. Cleaning by these methods is not recommended.
3.5.Inspect the passage in the Crossover Water Pump Housing for deposits. Remove all loose particles.
3.6.Replace EGR valve on engine, using a new gasket.

  1. EGR Passages in Crossover Water pump Housing.

4.1.Remove Crossover Water pump Housing.
4.2.Remove 2 plugs (2) and clean passages with a wire brush. Remove all loose particles.
4.3.Put Crossover Water pump Housing back on engine.

  1. Wash-up after any contact with deposits from the EGR System.

The best part of that is to test the pintle for free movement


Look over this information and let me know if you have further questions about this


Thank you



George H., ASE Certified Technician
Category: Cadillac
Satisfied Customers: 18270
Experience: ASE Master Tech 15+ Years
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