Volvo Oil In Coolant Reservoir – What You Need To Know

Are your concerned about seeing your Volvo oil in coolant reservoir? 

Well, it makes sense that your coolant should remain in your coolant reservoir while the engine oil must only stay in the engine. So, if these things get mixed up, then it is definitely not a good idea.

If you end up finding oil in your coolant reservoir, then this may concern you big time. After all, it’s not how it should be, right?

Today, we’ll discuss what happens when you have coolant and oil mixed together. Learn all about the causes of this issue, how to diagnose the problem, and the best way you can prevent it. 

volvo oil in coolant reservoir

Volvo Oil In Coolant Reservoir Causes

There are many reasons why there is oil in your coolant reservoir. We will discuss the causes more below but in a nutshell, it is due to a number of reasons such as damage to your coolant heat exchanger or blown head gasket. Sometimes, a crank in the engine can also cause this issue.

But before you even consider replacing or repairing any components, you need to first check if the coolant reservoir was not filled with motor oil by accident. Sometimes, some oil can slip into the coolant reservoir over time, which happens with older vehicles. Thus, if you have not changed your coolant in a long time, you may simply just need to get it changed now.

As we have mentioned, there are many reasons why there is engine oil in your coolant reservoir. Here they are:

1. Head gasket damage

This is perhaps one of the most common reasons behind having oil in the coolant reservoir. When your head gasket is leaking or faulty, you may end up spilling some oil in your coolant tank. Unfortunately, it can be a tad expensive to have this component replaced. It is also rather costly. 

The head gasket is a seal made of rubber, which is positioned right between your engine block and head. What this does is to ensure a tight seal since the head fits right onto your block. 

Moreover, the gasket makes sure that your combustion’s air pressure is unable to light up. This also prevents the oil in your engine reservoir from leaking out. If your engine stays overheated for a long time and is unable to cool down, this causes the head gasket to blow up. Hence, your oil then leaks into your coolant system. This is one of the reasons why you may see oil in the coolant reservoir.

Since replacing your head gasket can cost a lot of money, you may want to check the other components first before making a diagnosis and buying an expensive replacement part.

2. Damaged coolant or oil heat exchanger

Next up, your oil heat exchanger may have a crack, which then causes a mix up of the coolant and the oil. Thankfully, this should not be an expensive fix, as compared to replacing your head gasket. Furthermore, it usually is a common issue so you may want to get the oil heat exchanger checked to make sure it is not the problem.

3. Cracked cylinder head

Cylinders get damaged over time because of overheating. These may crack at certain areas, which then allows oil and air to leak out. Your cylinder head may also become warped because of your engine overheating, thus causing a leak to the head gasket. 

This is why it is important to get your cylinder head cracks fixed, although it can be quite difficult. Welding the component may also be necessary, especially in some areas. So, it may be worth getting it replaced instead of having it fixed. It is also cheaper to do, this is why you should consider getting it done before things get worse.

4. Engine block crack

Sometimes, a crack in the engine block may cause the oil to get mixed into your coolant reservoir. But once the engine block gets cracked, there is nothing left to do but to get it replaced since welding can be difficult.

Once the engine block has gone bad, this prevents proper cooling and oiling. When there is an extended heat building up, the block cracks and causes the residue oil to get inside the coolant reservoir. Be sure to diagnose it first before considering a replacement for your engine block.

5. Problems with transmission fluid cooler

There are instances when it may not even be engine oil in your cooling system but transmission fluid. Since your transmission also comes with a heat exchanger, it may be that you get coolant in your transmission fluid. While this is not common, it most definitely can happen. This is why it is important to get it checked before you assume that the problem is with your engine oil.

Read More: Dealing With A Charging System Failure Volvo Issue? Here’s What To Do!

Next Steps To Take

In the case of having oil in your coolant reservoir, you need to first check the pressure in the system. If everything appears to be fine, then you should try to remove coolant from your reservoir and then drive to see if more oil gets into it.

The most important thing is to determine what is causing a leak in your coolant system. This is why you should apply pressure on your coolant system and check if it pours out into your oil pan. A coolant pressure tool is what you need, as well as proper adapter for the coolant expansion tank.

However, these tools can be expensive, so it may be best to go to an automotive service center to get this done for you. 

If you are unable to find leaks – and yet you still lose pressure – check for coolant in your oil by using the dipstick or tapping the engine oil out to check if there is coolant in your engine oil. 

You should also check the other parts such as the head gasket, oil heat exchanger, and the engine block. Once you have figured out the problematic component, then you can work on making appropriate fixes to resolve the issue and prevent things from getting worse over time.

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