I was pretty pleased with the diesel engine in my 2008 Jeep Grand Cherokee up until I hit 68,000 miles and I noticed a drop in power. It wasn’t huge but it was definitely a bad sign. Sure enough, when I had it diagnosed it turned out to be the swirl valve. The defective valve damaged some other parts in there too. At this low mileage it turns out I’m gonna have to spend over $5,000 to get all of this repaired. Given how likely it is that this will happen again, should I just get rid of the vehicle?
When the swirl valve fails, a few things are happening. First, the exhaust gas recirculation valve (EGR) and its passages get clogged, leading to a seal in the positive crankcase ventilation (PCV) system leaking oil into the swirl valve. The combination of the EGR and PCV system failures causes carbon to build up and seize the swirl valve. If the valve fails in the closed position, it can cause a loss of power and the Check Engine light to come on.
Some owners try to bypass these items by having modifications done to the systems in hopes of lessening the cost of repairs. These modifications are illegal in the United States and are subject to large fines that may end up being higher than the cost of repairs. It is also fairly difficult to sell or trade an illegally modified vehicle.
I recommend having a certified mechanic, such as one from YourMechanic, perform the necessary repairs without uncertified modifications.