Mitsubishi 6G72 engine problems — Overview, Specs, Problems, & Reliability

The 6G72, under Mitsubishi’s most popular G2 engine lineup known for its reliability, is not perfect after all. The engine made its first debut in 1986, and due to its reliability, the production continued until 2008. However, it has flaws like every other engine.

If you want to swap your engine or get a new ride with the 6G72 engine, read these 6G72 engine problems before making that decision. You’ll learn 6G72 engine review, specifications, problems, and reliability.

Mitsubishi 6g72 engine Explained.

The 6G72 engine belongs to the Mitsubishi G2 engine family. It made its first debut in 1986 to replace the 6G71 engine — which is a 2-liter while the 6G72 is a 3-liter engine.

Soon after the 6G72 appeared in the market, Mitsubishi produced three other engines in the G2 engine family, making it five in the G2 series — 6G71, 6G72, 6G73, 6G74, and 6G75. Due to their reliability, the manufacturers equip most of their cars and several other American cars under Licence with these engines.

The 6G72 is a 3-liter V-shaped six-cylinder engine that comes in three different models. It features SOHC with 12 valves, SOHC with 24 valves, and DOHC with 24 valves. This means some of the SOHCs have two valves per cylinder, while other SOHCs and the DOHC have four valves per cylinder.

The first model — SOHC 12 valves, outputs 141 hp @5000 rpm and 172 pounds-feet of torque @3600 rpm. The second model — SOHC 24 valves, produces 195 hp @5000 rpm and 205 pounds-feet of torque @4000 rpm. The DOHC 24 valves used in Mitsubishi Debonair, Dodge Stealth, and 3000GT outputs 222 hp and 205 pounds-feet of torque.

The engine was designed and engineered with a cast iron block and a 60-degree camber — making it lightweight and compatible with various vehicle makes and models.

Let’s look at the 6G72 engine specs to better understand its capacity.

What cars have a 6G72 engine?

Before talking about the Mitsubishi 6G72 engine problems, let’s see the vehicles that use these engines so you can tell the cars that are prone to these issues.

Common problems of Mitsubishi 6G72 engine and solutions

Enough of the long talk on the review and specifications; here are 6G72 engine problems and their solutions you should watch out for.

The most common problems 6G72 engine owners complained about are minor engine knocking sounds, floating engine speed, interruption in the engine operation, and loss of engine power while driving.

Minor engine knocking sound.

The most prevalent 6G72 engine problem is a minor knocking sound while the engine is running. The problem often results from sticky or bad hydraulic valve lifters. All you need to fix this is to lose the valve cover and service the hydraulic lifters so they will function freely — without struggling to move.

In some rare cases, the knocking noise can also occur if the connecting rod bushing is worn or loose. If this is the case, you have to overhaul the engine.

Floating engine speed

Another problem 6G72 owners complain about is floating engine speed. This is common in several vehicles that use this engine. If you are experiencing this, check the idle speed control and adjust or replace it as needed. Plus, if the rpm needle is jumping up and down, inspect the throttle body and clean it if it is dirty.

Interruptions in engine operations

Most owners also complained about irregularities in how the engine operates. This is somehow a vague issue because of several factors, such as a failing idle air control valve, snapped timing belt, and dirty spark plugs. It can also result from a malfunctioning fuel system, such as a clogged fuel filter or faulty fuel pump.

The best way to fix this problem is to diagnose the vehicle and address the underlying issues before it escalates to something more serious.

Loss of engine power

Loss of engine power is another issue with the 6G72 engine. Diagnosing this problem is a bit complex since several issues could be the culprit. Loss of engine power is also one of the common 6g74 engine problems. However, I recommend you diagnose your car with an OBD2 scanner so you can quickly pinpoint the actual cause of the problem and fix it.

Sometimes, loss of engine power in the 6G72 engine leads to overhauling the engine. It may cause you to replace some major engine components, which will invariably drop expensive repair bills on the table.

Pros and Cons of Mitsubishi 6g72 engine

No engine ever built is perfect. Every engine has strengths and weaknesses, and the Mitsubishi 6G72 six-cylinder engine is no exception. Let’s look at some of its pros and cons to see why you should buy or avoid it.

Pros

Durability: In general, Mitsubishi engines are durable, and the 6G72 engine is not an exception. If you follow the manufacturer’s maintenance intervals, the engine will stand the test of time. No wonder Mitsubishi keeps using the G2 engine series to date.

Towing Capacity: The 6G72 Mitsubishi has a V6 configuration and reasonable torque, making it ideal for any vehicle built for towing. While it doesn’t have a crazy torque, it can tow moderate to heavy loads effectively.

Widely Available: As I explained earlier, the 6G72 engine is widely available and has been used in various vehicles, including cars from Hyundai, Chrysler, Dodge, and, of course, Mitsubishi. Also, the maintenance and replacement parts are available in the market.

Power Output: Depending on the version and application, the 6G72 engine can produce a decent amount of horsepower — making it ideal for both street and highway driving.

Cons

Age and maintenance: The main concern owners have about using the 6G72 engine is age and maintenance. Some of the 6G72 engines are over 37 years old — making them develop issues every now and then due to wear and tear.

Is the 6G72 reliable?

I know you will be asking, is the 6G72 a good engine, especially since some of its versions are nearly four decades old?

According to several owners, 6G72 engines are very reliable. The older versions crank easily, even on cold mornings, and start pretty fine. Replacement parts are easily accessible due to their wide availability.