Chrysler designed and manufactured the 3.7 PowerTech from 2002 to 2012. The engine served as the standard engine for Dodge Ram trucks and a variety of other Dodge and Jeep mid-size vehicles. With 210hp and 235 lb-ft of torque, the engine lacked power and efficiency, prompting its replacement.
The 3.7L PowerTech was revised in 2005, with the compression ratio increased, the combustion chambers redesigned, and the cam, piston rings, and cylinder head covers redesigned. Additionally, a 2007 addition included an electronic throttle body and exhaust gas recirculation.
Chrysler introduced the 4.7L V8 PowerTech engine in 1999 as the standard V8 option for Dodge trucks and Jeeps. The 3.7L V6 PowerTech engine is nearly identical to its larger V8 sibling, except for two cylinders.
In 2011, the new Chrysler Pentastar V6 engine began gradually replacing the 3.7 PowerTech, and by the end of 2012, it had been completely replaced. The Pentastar was a more advanced engine than the 3.7, providing more power and fuel efficiency.
Cars Using the 3.7L PowerTech
Despite the fact that the 3.7 PowerTech was technically manufactured by Chrysler, it was never installed in a Chrysler vehicle. Throughout this article, we will interchangeably refer to this engine as the Dodge, Chrysler, or Jeep 3.7 PowerTech.
The 3.7 PowerTech is also known as the 3.7 Magnum. Additionally, we use this interchangeably throughout the article.
- 2002-2012 Dodge Ram
- 2004-2011 Dodge Dakota
- 2004-2009 Dodge Durango
- 2007-2011 Dodge Nitro
- 2002-2013 Jeep Liberty
- 2002-2013 Jeep Cherokee
- 2005-2010 Jeep Grand Cherokee
- 2006-2010 Jeep Commander
- 2006-2010 Mitsubishi Raider
Dodge 3.7L PowerTech Common Problems
- Valve Seat Failure
- Stuck Lifters / Lash Adjusters
- Piston Ring Landings
- PCV Valve
1. 3.7 PowerTech Valve Seat Failure
Valve seats are located within the engine head and are responsible for completely sealing shut both the exhaust and intake valves when they are closed. When a valve is closed, its head rests against the valve seat.
When a valve seat fails, it can prevent the valve from fully closing, thereby compromising the airtight seal that aids in cylinder compression maintenance. With that said, the end result is a decrease in cylinder compression.
When a cylinder has insufficient compression, air leaks out of the cylinder as it attempts to compress it, effectively rendering the cylinder ineffective. This will have a significant performance impact but may also cause additional engine problems if left alone for an extended period of time.
Valve seat failure is most frequently caused by excessive engine heat on Dodge and Jeep 3.7 PowerTech engines. Excessive engine heat can warp the metal of the seat, causing it to pop out of its position.
3.7 Magnum Valve Seat Failure Symptoms
- Loss of engine compression
- Loss of power
- Lack of acceleration
- Poor overall performance
- Cylinder misfires
When a valve seat on a V6 Magum fails, it is typically isolated to a single cylinder. Fortunately, losing compression in one cylinder does not result in the loss of compression in the other cylinders; it is isolated to the cylinder with the failed seat.
Having only one cylinder fail can actually make detecting the problem more difficult. Your engine will effectively run on five cylinders rather than six, which may not be noticeable from a performance standpoint if you never touch the throttle.
Misfires will almost certainly be the most prevalent symptom. If you’ve replaced the spark plugs and ignition coils and still have misfires, the next step should be to perform a compression and leak-down test on all cylinders.
3.6 Magnum Valve Seat Failure Replacement
Because the valve seats are pressed directly into the cylinder head, the only way to replace them is to rebuild or replace the cylinder head entirely. Whether you choose to replace or rebuild the existing head, you’re likely to incur a $1,000+ repair bill. DIYing the repair is probably out of the question unless you are a skilled machinist.
One of the most effective preventative measures is to ensure that your engine never overheats. Heat destroys valve seats, so monitor engine temperatures and pull over if they begin to rise above normal levels.
Maintain a sufficient supply of coolant in your engine and flush/replace the coolant as recommended. If your engine has been modified with power mods, you may consider adding cooling modifications, but I do not recommend this for stock engines.
2. 3.7L Magnum Stuck Lifters / Lash Adjusters
The 3.7 Magnum is a four-cylinder engine with a single overhead camshaft (SOHC). Because the camshaft is located in the cylinder head, overhead cam engines do not technically have lifters. The 3.7 Magnum, on the other hand, features hydraulic valve lash adjusters that function similarly to conventional lifters.
While traditional lifters maintain a small amount of clearance between the cam follower and the valve, lash adjusters are mounted in the head and are responsible for maintaining zero clearance between the cam follower and the valve. If you’re interested in learning more about valve lifters, here’s an article.
The lash adjusters on the 3.7L Dodge Magnum engine are prone to becoming stuck. Oil-related issues are a frequent source of this problem. If you run too thick an oil or go an extended period of time without changing the oil, the lash adjuters may fall out of place.
When this occurs, the valve becomes stuck in the open or closed position, resulting in significant performance issues and other sporadic engine problems.
Symptoms of Stuck Lash Adjusters – 3.7 Magnum
- Typical lifter tick engine noise
- Cylinder misfires
- Loss of power, lack of acceleration
- Rough idling
Lash Adjuster Replacement Options
If your lash adjuster becomes stuck, your only option is to replace it. When this problem occurs, it is typically isolated to a single cylinder, which allows you to simply repair the single cylinder.
If you or your mechanic is already down there, however, we would recommend replacing the entire set. A single lifter will cost between $10 and $25 for an aftermarket brand, or you can upgrade to a high-performance set for closer to $100 per lifter but with increased reliability.
3. Piston Ring Landings
As seen in the illustration above, piston heads have rings or grooves that serve to seal the piston against the cylinder wall. These rings, sometimes referred to as ring lands, create an airtight seal against the cylinder wall.
The ring lands on the 3.7L Magnum and PowerTech engines have an inherent design flaw that results in excessive heat generation within the engine. Additionally, the engine’s oil drain holes are rather small, exacerbating the heat issue.
Excessive heat can degrade oil, causing it to gunk up and become trapped inside the engine. As discussed in the previous engine problem, this is the primary reason why the lash adjusters become stuck.
Excessive heat can have a number of negative effects on performance and can also cause serious internal engine damage. Additionally, it can result in the failure of a variety of other engine support systems.
Dodge and Jeep Excess Heat Implications
The following is a list of potential issues that can arise when an engine is exposed to excessive heat for an extended period of time:
- Major metal engine components such as the head, pistons, and valves can warp, resulting in the engine’s complete failure.
- Components of the cooling system, such as hoses, tanks, and radiators, can develop leaks and leak coolant, resulting in increased engine heat.
- Oil deposits sludge in the engine, clogging lash adjusters. Oil burns more rapidly, resulting in excessive oil consumption, which can cause internal components to rub against one another due to a lack of lubrication.
I want to emphasize that this is not a common occurrence. Due to the gravity of the issue, it is frequently exaggerated on the internet. Nonetheless, it has occurred frequently enough for leading companies, such as Powertrain Products, to publicly criticize Chrysler for its inherent flaws. Chrysler has maintained its engine’s integrity throughout the complaints.
According to Powertrain Products, this can happen as early as 75,000 miles on the 3.7L PowerTech / Magnum. Alternatively, we’ve read numerous accounts of these engines lasting well beyond 200,000 miles without experiencing any problems.
4. Positive Crankcase Ventilation (PCV) Valve
When fuel is burned in an engine, waste gases are produced. The majority of these gases are passed through the exhaust system, where they are further burned before being released into the atmosphere via the exhaust. However, some of these gases become trapped and can make their way down into the engine’s crankcase, which contains the engine’s oil.
The PCV valve is attached to the crankcase and is responsible for releasing any trapped gases. However, over time, the valve can become clogged with these gases, preventing it from opening or venting the gases.
When this occurs, the trapped gases condense in the crankcase, clogging the oil and turning it sludge-like. When this occurs, it can result in oil leaks throughout the engine, destroying seals, gaskets, and other components, as well as leaks through such things as the valve cover.
Chrysler 3.7 Magnum PCV Valve Failure Symptoms
- Rough idling
- Loss of power, poor performance
- Engine hesitation, sputtering
- Poor fuel economy
- Oil leaks (gaskets, seals, valve cover, etc.)
PCV Valve Replacement Options
Fortunately, replacing the PCV valve is an inexpensive and straightforward repair. When replacing the PCV valve, we recommend performing an oil change to flush the engine of any potentially contaminated oil.
The PCV valve is a relatively inexpensive part that can be installed by most people with some engine knowledge. Here is a how-to video for replacing the PCV valve on a Ram 1500:
Chrysler, Dodge, Jeep 3.7L Reliability
Is the Magnum 3.7L a dependable model? The engine, along with its 4.7L sibling, does not have the best online reputation. Certain serious problems, such as valve seats and lash adjusters, can result in catastrophic engine failure. However, these issues are not as prevalent as they may appear.
The most significant issue with the 3.7 is excessive engine heat. Keeping your engine from overheating or running hot is critical for reliability. Change the oil frequently and flush the coolant according to the recommended maintenance schedule to avoid any catastrophic failures.
We did not mention some items that are semi-common, such as head gasket and valve cover leaks, as well as water pump failure. All of these issues are caused by excessive heat, which is why proactive cooling system maintenance is critical for system reliability.
Certain engines begin to exhibit significant issues as early as 75,000 miles, while others, such as the 3.7 Magnum, have been reported to last well beyond 200,000 miles, and even into 300,000 miles. In general, these engines should last at least 200,000 miles when properly maintained.
If you’re concerned about major issues, you can upgrade various components of your cooling system, such as the radiator, to ensure your PowerTech is not plagued by excessive heat.