Dodge Ram 1500 Leaking Oil: Common Causes & Fixes

If your Dodge Ram 1500 has suddenly started leaking oil, you might be wondering what’s wrong and what you can do to fix it. It’s not a good situation to be in, and you might be worried that you’re facing expensive and complex repairs – so what causes this to happen?

The most common reason for a Dodge Ram 1500 leaking oil are worn out or damaged gaskets and seals. As the truck gets older and gets more miles on it, the high engine temperatures will eventually wear out the gaskets and seals and they will need to be replaced. Overheating the engine often will damage them a lot faster.

Figuring out what’s causing the oil leak is a crucial part of getting it fixed, so it’s important to diagnose and examine each of the potential problems. We’re going to run through the common causes and the best fixes in this article today.

Number 1 Reason For An Oil Leak In A Dodge Ram 1500

Gaskets and seals are used throughout the engine in a Dodge Ram 1500, and with time those will degrade and wear out and start leaking oil. These seals and gaskets are usually made of silicone or rubber which will become hard and brittle and this will lose its ability to hold back the oil.

Another thing that speeds up the wear on the gaskets and seals is heat. When an engine gets overheated often, not only do they start to wear out faster but the metal parts that get overheated start warping, which also creates uneven surfaces adding to the problem. Overheating of the engine can be caused by not changing oil often enough, or not having enough coolant in the system which will raise the temperature significantly.

The common places where a gasket or seal can fail is the valve cover, oil pan, rear main seal.

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How To Fix It

This is not an easy fix, unless the leak is from the valve cover. The valve cover is pretty easy to access and remove so you can replace the gasket in it. The oil pan is also fairly easy to access to replace the gasket. The rear main seal on the other hand is very hard to access. This will most likely require taking your truck to the mechanic and have them do it where they have all the tools necessary but also a lift that can get the truck off the floor for ease of access to all the components.

The idea here for this problem is to replace the gasket or seal. This means you need to buy a new one, remove the part and replace the gasket or seal and install the part back on the truck.

Cause 2: Oil Cooler/Filter Housing Failing

Very often, if your Dodge Ram 1500 starts leaking oil, it’s because something in the oil cooler or filter housing has failed and is letting oil pass through. This is usually due to one of the o-rings in the filter losing its flexibility, and allowing oil to seep past it.

In other cases, it’s because the housing itself has got cracked, and has a gap that the oil can leak through. This may be due to general wear and tear on a high milage Dodge Ram truck, or the result of an accident.

Whichever of these things has happened, you will need to repair it. Oil that is allowed to leak out can end up pooling in the engine, or even running into the transmission, which can do serious damage to your vehicle.

How To Fix It

Unfortunately, this problem is not a particularly easy fix in most cases, because you will need to remove other parts in order to access this bit of the engine.

The upper and lower intake manifolds have to be removed before you can reach it, and you need to be very careful not to let anything drop into the intake valves once they have been exposed.

It’s generally best to get a mechanic to do this job for you, rather than risk doing further damage to your vehicle. However, if you want to have a go, you will need to purchase either a replacement housing, or replacement o-rings.

Doing it yourself makes the repair cheaper, but you need to be completely confident that you can manage the job.

Cause 3: Head Gasket Is Blown

Head Gasket

In some cases, an oil leak will be due to degraded or blown head gaskets. Again, it’s important to address this kind of leak swiftly, because the oil could get into your vehicle’s engine, as well as the HVAC system, and the radiators. As soon as you notice the leak, check the gaskets.

In some cases, just tightening the gasket will be sufficient, because the leak is a result of it being too loose. In other cases, you’ll need to replace the gasket.

If your head bolts are loose, this is a bad sign. This means the heads have been overheated numerous times. This can mean that they are warped and will require major repairs.

How To Fix It

There are a few things you can do if you think a head gasket might be leaking. Firstly, check is the area where the heads meet the engine block has oil on it. You might be able to do this yourself with a flashlight and you may need to remove a few parts to access this area, or you can get a mechanic to check it for you.

If it is determined that the head gasket is blown or leaking, you will need to do some major engine work. The heads will need to be machined to get the straight again. If possible, the engine block will also benefit from a machining, so the area that meets the heads will be straight and level too.

You will also need a set of head gaskets. It is common to buy a complete engine rebuild kit that comes with all the gaskets and seals you would need to rebuild an engine. It only makes sense to rebuild it once you got it apart to do the machining. All the seals get replaced and all the parts that wear out and are hard to access when the engine is together would get replaced as well, like oil pump and water pump. All the sensors can also be replaced at the same time.

Cause 4: Ruined Oil Pan Gasket

Sometimes, a leak is the result of your oil pan gasket having failed. The gasket is subjected to a lot of different stressors, temperature changes, and vibration, which can cause it to fail. This will allow oil to seep out and into the engine. You need to address this quickly.

In other cases, the bolts that hold the pan in place will have loosened due to the vibrations of driving, and this can also cause a leak.

How To Fix It

To figure out what’s going on, you need to crawl under the vehicle and inspect the oil pan. Check if the gasket seems to be leaking by inspecting it for oily residue, and see if the bolts have loosened.

If the bolts have loosened, you can tighten them again, but be aware that you need to do so in the right sequence, and to the right torque spec. This will depend on the specific year of your vehicle, so talk to your local mechanic or consult your handbook for this information before you make a start.

Over-tightening will damage the threads and can destroy your oil pan, causing further leaks.

Cause 5: Problems With The Drain Plug

If your drain plug has been damaged by something or is worn out, it will generally result in an oil leak. Many experts suggest that the oil plug and its seal should be replaced after each oil change, and if they aren’t, they may start to leak.

You can check whether the oil plug is tight enough by crawling under the vehicle and inspecting the plug, which is at the bottom of the oil sump. You may be able to see oil around the seal or around the plug, and you might also notice that the plug is starting to get rounded, which indicates that it has been used multiple times without being changed.

If you see either of these signs, the drain plug is probably the issue.

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How To Fix It

If you think the drain plug or the seal could be causing the problem, it’s time to replace them. In general, it’s best to replace both components, as these don’t tend to be too expensive, and this will ensure you have resolved the issue.

You don’t have to drain all of the oil out of your Dodge Ram 1500 to do this, fortunately, although you will lose some oil. As long as you work quickly, you can unscrew the plug with your right hand, and use your non-dominant hand (with gloves on) to plug the hole while you get the new washer and plug ready.

Release with your non-dominant hand and screw the new seal and plug into place as quickly as you can. Some oil will spill, but if you’re quick, you can avoid losing much. Put something down to catch the spillage.


As you can see, quite a few different things can cause a Dodge Ram 1500 to leak oil, and it’s important to understand the common causes and how to fix them. Make sure that for safety reasons, you don’t attempt any oil-related repairs while your engine oil is hot, as there is a high risk of burns.

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