I am an expediter that drives 10,000 miles per month. I use only full synthetic oil that meets the Chrysler oil spec, and I stick to the 10k miles oil change interval, because I needed maximum life out of the Promaster drive train. The van threw a check engine light that two dealers confirmed was a "number 5 cylinder misfire. "
After a fuel system clean, throttle plate clean, tuneup, new spark plug coil, new fuel injector, new fuel injector coil, numerous tests by the Promaster technician and two Pentastar engine technicians, escalation and tests suggested by Chrysler technical support, and three more hours of detailed inspection and testing, the conclusion is that the #5
cylinder has failed. So I either pay for an engine rebuild or a new engine.
I found out online that this Pentastar engine has a history of this type of failure on the #2
cylinders, and that Chrysler agreed to fix them at no charge and extend the warranty on that side of the engine to 150k miles.
I opened a case with Chrysler corporate, and have now been offered the repair of the #5
cylinder for $1,500 plus the $1,000 the dealer has already charged. Or I can get a new assembly line engine for a discounted price of $3,700.
My truck is my business. After this mess, and my lack of confidence in the reliability of this van, I have to admit to myself that this purchase was a mistake, and I should have bought the more expensive Sprinter.