Problem Description and Possible Solution
Screws inside the intake manifold can become loose causing internal engine damage if they fall out completely. Our technicians report that using a strong thread locker on the power valve butterfly screws can help prevent them from becoming loose. The manual transmission models reportedly do not have the intake manifold power valves.
Average mileage: 110,888 (45,000–188,000)
Engine affected: Automatic Transmission
14 people reported this problem
Wile driving car, loud knocking began. Took car to repair shop for diagnosis, he found screws missing, and 2 screws inside the engine! Said he had never seen anything like that before and Nissan should be notified. Nissan doesn't want to claim any responsibility for the issue, but we are going to take it further and make it more public if necessary to alert other owners of these vehicles. If we are out $3,000 to fix it, they are going to get some really bad publicity.
My 2004 Pathfinder was idling in a parking lot when it started making a loud (once per revolution) click in the right head. The local dealership wasted a day trying to find out if there was a oil passage blocked (really guys?). Then they threw up their hands and quoted me $4400 for a replacement used engine (installed). I asked if they could tell me if the problem was related to the power valve screws and the service manager said it would take 26 hour of labor to diagnose and replace the head, if the block was still servicable. Nissan's regional service rep called and told me she was sorry about my motor but Nissan could not help. Well, I'm sorry but I'll never buy a Nissan again. No one spends that kind of money to get 100K out of a car, this isn't 1968, and it's not a rambler.
While stopped at a stop sign, a loud knocking began to occur. A mechanic took the intake manifold off and found that all the screws were loose and 1 was missing. It got pulled into the cylinder and damaged the piston.
I heard loud engine knock that lasted a few minutes before disappearing. I removed upper intake plenum to discover 1 missing power valve and two screws. The knock I had heard was power valve screw inside cyl. before it made it's way out the exhaust. I found the loose power valve stuck in an intake runner.
Engine sounded like it had come apart inside. I had a used engine installed and kept the old one. Tech said butterfly valve screw came loose and fell into engine, happens often. I still have the engine if someone wants to sue and use it as evidence.