Mercedes-Benz Parts Catalog Mercedes-Benz Accessories Catalog Mercedes-Benz Technical Articles Mercedes-Benz Tech Forums
 
Follow Pelican Parts on Facebook Follow Pelican Parts on Twitter Follow Pelican Parts on Instagram Follow Pelican Parts on YouTube Follow Pelican Parts on Pinterest Follow Pelican Parts on Tumblr
  Search our site:    
View Recent Cars  |   Cart  | Project List | Order Status | Help    
 >  >
EGR Change Over Valve Replacement
 
Bookmark and Share

Pelican Technical Article:

EGR Change Over Valve Replacement

Steve Vernon

Time:

2 hours2 hrs

Tab:

$350

Talent:

***

Tools:

13mm, 12mm socket, 13mm wrench, 6mm Allen

Applicable Models:

Mercedes-Benz W123 (1977-85)

Parts Required:

EGR valve gasket, EGR valve, thermostat housing gasket

Hot Tip:

Test it before replacing

Performance Gain:

Pass a SMOG test

Complementary Modification:

Change the oil filter

The EGR valve or Exhaust Gas Recirculation Valve recirculates exhaust gases into the intake manifold to be burnt. This helps the vehicle with emissions and if your car is running "dirty" the EGR valve may be stuck closed. While there are a great many people on the internet who suggest eliminating the valve or plugging the vacuum line so the valve remains closed, be aware that it is illegal to tamper with or defeat emission controls on a vehicle. Please check your state and the federal regulations before performing any work on your emission system that is outside the stock or standard practice from the manufacturer.

Remember your car may have been serviced before and parts replaced with different size fasteners used in the replacement. The sizes of the nuts and bolts we give may be different from what you have so be prepared with different size sockets and wrenches.

Protect your eyes, hands and body from fluids, dust and debris while working on your vehicle. If working with the electrical system, disconnect the battery before beginning. Always catch fluids in appropriate containers and properly dispose of any fluid waste. Recycle parts, packaging and fluids when possible. Never work on your vehicle if you feel the task is beyond your ability.

Our vehicle may vary slightly from yours as models do change and evolve as they grow older. If something seems different, let us know and share your info to help other users. Questions or want to add to the article? Leave a comment below. When leaving a comment, please leave your vehicle information.

The EGR valve is located on the right side of the motor right by the thermostat housing (red arrow)
Figure 1

The EGR valve is located on the right side of the motor right by the thermostat housing (red arrow)

If you are wondering if the valve is working or not, you can perform a simple test by removing the vacuum line from the top of the valve and apply some vacuum (red arrow).
Figure 2

If you are wondering if the valve is working or not, you can perform a simple test by removing the vacuum line from the top of the valve and apply some vacuum (red arrow). There is a viewing port on the valve (yellow arrow) where you should be able to see the valve open. If you cannot see the valve, a simple check to see if the valve is holding pressure or not is to suddenly remove the vacuum line--you should be able to hear the valve snap shut. If the valve is not holding pressure or not opening or closing it is broken.

This photo illustrates the viewing port (red arrow) on the EGR valve with it out of the vehicle.
Figure 3

This photo illustrates the viewing port (red arrow) on the EGR valve with it out of the vehicle.

If you are replacing the EGR valve (red arrow) you will need to remove the turbo air intake hose (yellow arrow) to access the mounting hardware.
Figure 4

If you are replacing the EGR valve (red arrow) you will need to remove the turbo air intake hose (yellow arrow) to access the mounting hardware. Mercedes reconfigured the mounting design over the years so check on your vehicle before ordering parts. On our 1985 300TD you need to remove the A/C line mount to access the valve. Unfortunately this also means loosening the thermostat housing as well, which will require replacing the thermostat housing gasket.

Disconnect the vacuum line from the top of the valve (red arrow).
Figure 5

Disconnect the vacuum line from the top of the valve (red arrow).

With the air duct removed you can see the clamp connecting the hose from the exhaust to the EGR valve (red arrow).
Figure 6

With the air duct removed you can see the clamp connecting the hose from the exhaust to the EGR valve (red arrow). The yellow arrow points to the A/C bracket mount which also holds the thermostat housing in place.

Use a 13mm (red arrow) and 12mm socket (yellow arrow) to remove the housing hardware.
Figure 7

Use a 13mm (red arrow) and 12mm socket (yellow arrow) to remove the housing hardware. Note on our car that means replacing the thermostat housing to head gasket.

Use a 13mm wrench and disconnect the hose to EGR valve clamp (red arrow).
Figure 8

Use a 13mm wrench and disconnect the hose to EGR valve clamp (red arrow).

There are two 6mm Allen bolts holding the valve to the intake manifold, use a 6mm Allen and remove the two bolts (red arrows).
Figure 9

There are two 6mm Allen bolts holding the valve to the intake manifold, use a 6mm Allen and remove the two bolts (red arrows).

You can now remove the EGR valve from the motor; do not forget to install a new gasket when installing the new valve.
Figure 10

You can now remove the EGR valve from the motor; do not forget to install a new gasket when installing the new valve.

With the valve off make sure to clean up the exhaust pipe (red arrow) and intake (yellow arrow) before installing the new valve.
Figure 11

With the valve off make sure to clean up the exhaust pipe (red arrow) and intake (yellow arrow) before installing the new valve. Installation is the reverse of removal.

Bookmark and Share

  Search our site:    

View Cart & CheckOut | Project List | Order Status |  Help    

 

[Home] [Customer Service] [Shopping Cart] [Project/Wish List]
  [Privacy Statement]  [Contact Us] [About Us] [Shipping] [Careers]

Copyright © Pelican Parts Inc. -    DMCA Registered Agent Contact Page

Page last updated: Fri 12/9/2016 02:59:24 AM