The 4.7L V8 engine is a product of the AMC belonging to the Powertech family of the machine. It is an eight-cylinder engine that powered various Jeep, Dodge, and Chrysler vehicles.
It is the first engine developed to wear the vacant shoes of the 4.0 inline-six engine- which is made by AMC and 316 V8s of Chrysler.
The engine remains the standard-bearer of the Powertech family. Throughout the years, they have considered this engine as conservative, but why do they say so?
Let’s take a little tour of the 4.7 Magnum / 4.7 Powertech engine.
What are Chrysler 4.7 V8 Powertech Engines?
The 4.7 V8 Powertech engine is the first Powertech engine ever released, almost contemporary with the 3.7 Powertech engine. If you take a look side by side on both engines, they are identical.
Their only difference is that the 4.7 Powertech has eight cylinders instead of the six-cylinder in the 3.7 Powertech engine.
The 4.7 Powertech engine is a notable member of the Powertech group of engines. It is the pioneer and will always bear the name of Powertech for the years to come. However, this engine’s production has come to a halt to make way for the distribution and introduction of the Chrysler 3.6 Pentastar engine.
As we mentioned earlier, the engine design of the 4.7 Powertech engine revolves around the idea of durability and longevity. It will be placed on trucks. Therefore it needs to withstand the demands and sufficiencies of the truck.
The then-AMC or American Motors Corporation designed the engine before joining Chrysler.
In 1999, the 4.7 Powertech engine debuted in the Jeep Grand Cherokee. The initial rated output was 235 HP and 295 lb-ft of torque. Several years after the release, Chrysler introduced the 4.7 HO still in the Jeep Grand Cherokee as an option.
The ‘HO’ version means ‘High-Output’ with larger power and torque output – 265 HP and 330 lb-ft of torque. However, the 4.7 HO version was discontinued in 2009.
Engine Specifications and Design:
- Production Run: 1999 – 2013
- Cylinder Head Material: Aluminum
- Cylinder Block Material: Cast-iron
- Configuration: V8
- Bore: 93.0 mm
- Stroke: 86.5 mm
- Valvetrain: SOHC two valves per cylinder
- Displacement: 4.7 L (4698 cc)
- Compression Ratio: 9.0, 9.7, and 9.8
- Weight: 460 lbs.
- Maximum HP: 310 HP at 4,600 – 5,650 RPM
- Maximum Torque: 334 lb-ft at 3,600 – 4,000 RPM
The 4.7 Powertech engine shares the same materials as the 3.7 Powertech engine. The engine has a cast-iron cylinder block with a 90-degree angle between cylinder banks. The optimal range when using one crankpin journal for pair of connecting rods.
Representing Powertech in its initial release, the block was created for this purpose.
Further, the engine has a nodular cast-iron crankshaft attached to the block by using a single bedplate instead of the usual five main-bearing caps. This adds more rigidity and durability for the bock too. The bedplate is made of compacted graphite iron (CGI).
The connecting rods are made from powder-forged metal; pistons are cast aluminum with moly coated skirts.
On the underside, a stamped steel oil pan seals the crankcase. And while the 3.7 Powertech engine has a balancing shaft, the 4.7 Powertech does not have any.
The cylinder heads are cast aluminum with a three-layer laminated stainless steel gasket between each head and engine block. Each cylinder head has two valves per cylinder, contrary to the usual four, and a top-mounted chain-driven hollow camshaft.
The intake and exhaust camshaft is designed around the idea of making the combustion chamber more efficient.
The diameter of intake and exhaust valves are 48 mm and 37 mm, respectively. The valve train newly-tuned length runner intake is equipped with hydraulic lash adjusters. Mounted at the top of the cylinder head is a cast magnesium valve cover.
Chrysler 4.7 Powertech engine uses an electronic fuel injection system or sequential multi-port injection. These fuel injectors are placed to the intake port in the head. The newly tuned length runner intake manifold is made from polymer and an electronic throttle body for speed management.
The 4.7 Powertech features a hybrid cooling fan system and a modern coil-on-plug ignition system.
High Output Version
The high-output version of the 4.7 Powertech engine was introduced in 2002 as an option in the Jeep Grand Cherokee Limited and the standard-bearer for the Overland vehicle. The most evident and somehow pretty overstated is the increase in power and torque.
Well, I can’t contest with that because that’s true from all angles.
Chrysler upgraded the engine with high-compression domed pistons, two knock sensors, a higher compression rating, new camshafts, and intake. The 4.7 High output version was replaced by the 5.7 HEMI – also by 3.6 Pentastar, but for some models, it was offered until 2008.
In 2005, the basic version of the engine received an update. It was equipped with two knock sensors and other minor changes to improve performance. On the other hand, a major upgrade was made done in the 4.7 Powertech in 2008.
The engine got new cylinder heads but still two valves per cylinder; a new slant-squish combustion design. The engine bottom has new pistons and forged steel connecting rods. The compression rating was also increased from 9.0 to 9.8.
The ports in the heads and the valve lash adjuster system, are also redesigned to have a better flow. To add, the camshafts are dressed with a more aggressive profile along with a shorter but improved intake manifold.
The tail end of the upgrade resulted in a 310 HP and 335 lb-ft of torque.
Applications of the Chrysler 4.7 Powertech Engine:
- 1999 – 2009 Jeep Grand Cherokee
- 2000 – 2007 Dodge Dakota
- 2002 – 2007 Dodge Ram 1500
- 2000 – 2009 Dodge Durango
- 2006 – 2009 Jeep Commander
- 2007 – 2009 Chrysler Aspen
- 2006 – 2007 Mitsubishi Raider
Applications of the Chrysler 4.7 High Output Version:
- 2007 – 2008 Jeep Grand Cherokee
- 2002 – 2004 Jeep Grand Cherokee
- 2007 – Dodge Dakota
- 2007 – 2008 Dodge Ram 1500 and Ram 1500
Problems Surrounding Chrysler 4.7 Powertech Engine
Though it received several updates throughout the years, the engine also suffered from some of its shortcomings. Moreover, the overall engine profile of the 4.7 Powertech resembles a stout figure for V8s at that time, so we can say that this engine “somehow” made the first impression of the stout V8s.
Well, in this part, we will break down some of the common issues for the 4.7 Powertech.
1. Valve Seat Failure
The valve seats of the 4.7 Powertech engine have the same issues like the 3.7 Powertech engine – they fail. The primary role of the valve seats is to seal the intake and exhaust valves when they are shut.
To illustrate, it is like a sealant on your window or door, so no water or air will come in or out.
Well, if the valve seats fail, the effects can be pretty detrimental to the engine. The first concern is the seal of the valves. Along with that, the compressed air inside the cylinder will leak, causing a serious problem in the engine performance.
Leaving this issue for a long time without any aid will put your engine in jeopardy.
Valve seat failures also contribute to overheating, another branch of the overheating issue, which will lead us to the next issue.
Overheating of the 4.7 Powertech engine is a combination of multiple that fails one after the other – especially the cooling system. A cooling system is important to keep the temperatures regulated in the engine.
Components such as the thermostat, water pump, radiator, cooling fan, coolant, and coolant hoses are subjected to wear and tear. Though some of them last more than the other, failure of a single component might lead to failure of the other.
3. Valve Cover Leaks
This is also a common issue for the 4.7 Powertech engine. As the engine age and mileage numbers pile up, valve cover gaskets deteriorate and develop cracks. Most of the time, oil leaks are the first symptoms of this issue.
It should be addressed at your pace, but I recommend immediately fixing this thing because the internal components will suffer if the leaks continue.
4. Head Gasket Failure
Again, concerning the age and mileage of the engine, failure of head gaskets happens when the mentioned factors take their toll. The most common result of head gasket failure is overheating.
The majority of the engine will eventually experience this issue if they flat out ignore overheating in some ways.
The Chrysler 4.7 Powertech engine opened its services to the Grand Cherokee in 1999. In that period, the engine garnered enough attention to showcase its build. It has different views from different people who experienced the engine.
Some say the engine is too old-school for them; others dig it because it is strong and durable.
But one thing stays true, the engine is reliable and can last for a long time. If it’s not for a replacement, the engine might probably still be present.
Maintain a disciplined maintenance schedule, use thin oils, and shorten the interval of the oil change as the engine age.