Changing spark plugs on the Jeep Grand Cherokee L requires removing the intake plenum.
The toughest parts about removing the plenum are two bolts on the right side that support the plenum to the engine. I found it was easier to remove the wiring harnesses (after disconnecting the battery), for the engine computer and the connection to the right hand front body wiring harness. I also removed the radiator fluid reservoir. This allowed plenty of clearance to remove the upper plenum. There is enough wiggle room to pull the EGR valve out of the plenum what's the plenum is separated from the manifold.
Also, note when you have the plenum off it's a good time to replace the PCV valve. I found that my plugs were oil fouled (100K miles) and there was oil in the PCV valve tubing and in the plenum.
Side note replacing the PCV valve with the plenum in place was not an easy task. Long reach, small arms are required to get to the PCV valve which is located on the rear valve cover on the right hand side, the tubing can be removed easily (push white lock and pull off), but rotating removing and reinstalling the PCV valve was quite challenging.
I wish I would have replaced the PCV valve while the plenum was off.
Hope this helps.
The toughest parts about removing the plenum are two bolts on the right side that support the plenum to the engine. I found it was easier to remove the wiring harnesses (after disconnecting the battery), for the engine computer and the connection to the right hand front body wiring harness. I also removed the radiator fluid reservoir. This allowed plenty of clearance to remove the upper plenum. There is enough wiggle room to pull the EGR valve out of the plenum what's the plenum is separated from the manifold.
Also, note when you have the plenum off it's a good time to replace the PCV valve. I found that my plugs were oil fouled (100K miles) and there was oil in the PCV valve tubing and in the plenum.
Side note replacing the PCV valve with the plenum in place was not an easy task. Long reach, small arms are required to get to the PCV valve which is located on the rear valve cover on the right hand side, the tubing can be removed easily (push white lock and pull off), but rotating removing and reinstalling the PCV valve was quite challenging.
I wish I would have replaced the PCV valve while the plenum was off.
Hope this helps.
