The Dodge 4.7-litre PowerTech V-8 engine has received mixed reviews from owners since its debut in 1999. Yet most of its quality issues centre on lack of scheduled maintenance that will doom any engine to an early death. The 4.7-litre V-8 is more compact and delivers more power than its predecessor, the 5.2-litre engine.
The 4.7-litre aluminium engine was first introduced in the 1999 Jeep Grand Cherokee and then the Dodge Dakota pickup and Durango SUVs a year later. The Dodge Ram picked up the 4.7 in 2002. Horsepower ranges from 302 horsepower with 149kg.-feet of torque in the Dakotas to 310 horsepower and 149kg.-feet of torque for the larger Ram pickups, according to allpar.com
Like all automakers, Chrysler LLC, the parent company of Dodge, adheres to a strict warranty policy. Engine failure, a recurring issue with Dodge Durangos and Dakotas, has centred on the lack of proper maintenance. Although an owner may provide evidence of regularly scheduled maintenance on the vehicle, evidence of oil sludge, metal shavings or failure to replace parts at scheduled intervals could void the warranty.
Engine failure can occur after 70,000 miles due to poor or lack of maintenance. But engine failure also has been known to be caused in some 4.7-litre engines with abnormally thin engine block walls on some engines. The thin walls cause excessive heat, which over time will cause oil to become gummy and the heads to crack. Only strictly following the factory recommended maintenance schedule can minimise the exposure to engine failure and ensure the warranty will be honoured.
Although engine failure in the Dodge 4.7-litre V-8s haven't reached significant proportions, carcomplaints.com reports that owners have complained of sudden loss of oil pressure with as little as 36,000 miles on the engine. Internal examination of the engine has found oil sludge to be present, although diagnostic checks fail to pinpoint the source of the failure.
Oil sludge appears to be a common problem with the 4.7 engine. It has been known to build up in no matter what the weight of the motor oil. Oil sludge is usually due to a faulty positive crankcase ventilation, or PCV, valve. Changing the PCV and switching to high-mileage oil will probably solve the problem, according to bobistheoilguy.com.
The 4.7-litre with more than 70,000 miles is in danger of cracking a head if the driver continues to drive it when the engine is running at 235 degrees on flat surfaces and up to 250 degrees on hills or towing a trailer. A diagnostic of the radiator, thermostat, water pump and gauge should pinpoint the problem.
Oil foam, usually evident on the oil dipstick or inside the oil cap, also is a result of a faulty PCV valve. A properly working PCV valve vents out excess condensation that builds up. The 4.7-litre V-8s prone to oil foam may require a 3,000-mile oil change instead of the 6,000-mile changes recommended in new models.