Clean EGR valve Z19DTH
Over time the Exhaust Gas Recirculation valve (EGR) become sized causing the following symptoms:
Loss of power up to 2000 RPM.
Increase in fuel consumption.
Increase in black exhaust smoke.
Higher CO emissions.
Motor Control System Failure Warnings / Check engine warning lights.
Tools Required:
- Socket Set with the following: 8mm, 10mm & 13mm
- 8mm Spanner or Long reach socket
- Hammer
- Drill and 3mm to 4mm drill bit (HSS)
- 3mm or 4mm punch or similar.
- Tub to clean the EGR body in
- Vice or workbench.
Consumables Required:
- Carb Cleaner.
- Grease.
- Fine sandpaper / wet ‘n’ dry paper.
- Highly recommended: some latex gloves, carbon dust is pain to get out from under your nails!
With thanks to Chris Potter who made this description for an Alfa JTD, the egr is identical to a Z19DTH.
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The EGR valve is located on the inlet manifold at the rear right of the engine. Remove the electrical connector on the left and side of the EGR valve. Press the yellow clip downwards and the connector should pop off downwards. Next remove the oil breather pipe bracket, the bracket is held on with 2 x 8mm nuts. |
| Remove the two long bolts (2x 13mm) bolts holding the pipe that runs from the EGR to the exhaust. It has a heat proof material on it. There is a thin alloy gasket between the pipe’s flange and the EGR body, don’t drop it down the back of the engine ! |
Next, remove the four bolts holding the EGR to the inlet manifold (4 x 10mm, 2 will require a spanner or long reach sockets). Two are regular bolts, two have short stubs for the oil breather pipe bracket. |
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The EGR should come easily off, the next photos show the soot and debris on the manifold side, and the pipe that leads to the exhaust. Clean out any loose soot and debris from the inlet manifold.
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Remove the four torxbolts (T25) connecting the solenoid valve and the electronic unit. |
| Below the pollution to the EGR control unit. | Below the pollution to the solenoid |
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| Check that the spring loaded valve in the EGR body still moves freely, if it doesn’t you may wish to soak the EGR valve in Carb Cleaner overnight, or attach it with tools!, The next two pictures show the build up of soot both inside the EGR body and the end of the solenoid. | |
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Cleane the valve-unit with a carb cleaner and leave it for some time in the cleaner. In meantime go to the next step. |
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Make the front end of the solenoid clean. Check the operation of the solenoid. You’ll find the end of the solenoid is either stuck fast in the body, or requires a fair bit of force to move in and out. It’s on a spring so should easily pop in and out. If it doesn’t you’ll know at this point that you have found a problematic EGR! If you need to clean the solenoid take the next steps. If cleaning is not needed, take the last step. |
 Securely hold the EGR solenoid in a vice or work bench. Drill a hole 3mm to 4mm in diameter in the plastic as shown in the picture. |
Next take a 3mm or 4mm punch to the inside of the solenoid, and knock out the insides. If might take quite a bit of force... be brave... and catch the insides when they come out ! (There are two springs, a large one at the end, and a very small one that fits snug on the solenoid pin.) |
| Next, a couple of photos showing the insides of the solenoid. | |
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Clean up all parts of the solenoid, with a little wet ‘n’ dry paper or similar. Clean out the inside of the solenoid casing. Smear, the solenoid with grease, shy away from copper slip. |
| Fit all parts of the internals back together, and slide the solenoid body back over them. Turn the solenoid back over and hold again the vice or work bench, and using a socket knock down the end of the internals so they are flush with the housing. | |
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| Once it’s all back in place, the pin on the solenoids internals should easily be able to move in and out, it should be sprung to the out position. If you can’t push it in and out with minimal effort, a little more cleaning may be required. | |
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Dry out the EGR body that has been soaking in Carb Cleaner, and re-attached to the Solenoid. Remember the mark you made earlier? Align the marks. Bolt the EGR back on to the manifold, put the alloy gasket between the body and exhaust inlet pipe, and bolt the pipe flange to the EGR body. Reconnect the electrical connection to the valve.. and your all done. |
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