Causes Of Excessive Crankcase Pressure Turbo

You may have been wondering about an excessive crankcase pressure turbo issue. Perhaps, oil is being blown right out of seals, or there is gas that blows through your oil fill cap. Or maybe you have discovered oil that burns through your exhaust.

If you are worried about an excessive crankcase pressure turbo problem, keep reading to learn more about the common causes of this problem.

excessive crankcase pressure turbo

What Causes An Excessive Crankcase Pressure Turbo Problem

For the most part, a turbo engine has been linked with a number of excessive crankcase pressure issues. If you are concerned about it at the moment, then it is best to learn more about the possible reasons why this happens.

1. Obstruction to the PCV System

An excess in the crankcase pressure is usually linked with a PCV system blockage. For the most part, turbo engines operate well under idle. However, once you drive your vehicle, you may discover oil around your engine bay. There may also be oil that burns through your exhaust, as well as after removing your oil fill cap or dipstick.

Additionally, there may also be gas blown out of any hole that was opened. When driving in normal conditions, your PCV system usually has a free-flowing and unobstructed path from your crankcase. This is usually through your valve cover, intake manifold, PCV pipe, and your cylinder head PCV port. Lastly, it also has a patch at the check valve located at your turbo inlet before returning to your turbo inlet. 

Obstructions in the path mentioned may happen due to certain reasons. These include:

The use of aftermarket covers for the valve

This is usually an issue experienced by folks who come across an excess in the crankcase pressure.  It happens whether immediately upon installation or during the first few weeks of driving. Your valve cover fails sooner and causes a restriction in your PCV system. 

Then, this obstruction leads to a high crankcase pressure. Since there is nowhere for it to escape, it tends to find the quickest path available. This may be the front crank or the main seal, or the valve cover gasket. 

The best way to fix this issue is by replacing your valve cover, which is an OEM unit as your best option. Otherwise, aftermarket covers may cause further issues.

PCV deposits

Another reason why an obstruction occurs is because of some PCV deposits. This is why you need to use a good quality oil in your PCV system. Otherwise, PCV liquids and solids such as combustion byproducts, fuel and condensation can build up over time. Your PCV port located on your cylinder head and your intake manifold PCV port may also have deposits.

This is why you should check for deposits by either removing your valve cover and checking your PCV port close to the engine’s firewall side. Be sure there are no obstructions and it is perfectly clear of any debris. If you need to clean it up, you should remove the intake manifold first since this component is likely to have some deposits. Be sure to clean out the debris well and ensure that no deposits are left behind. 

2. Frozen or stuck check valve at your turbo inlet

There is a check valve to your PCV pipe located from your intake manifold and to your turbo inlet. Unfortunately, once the check valve gets stuck or gets frozen because of condensation during the cooler months, the PCV gas flow will be blocked.

3. Piston ring land cracks

It is not typical to happen, yet it can occur – and it is the last thing you want to happen. This is also one of the common reasons behind excessive crankcase pressure. 

Because of low octane fuels, excess oil consumption, or other situations that lead to a LSPI, the piston ring land may crank. What happens is that a portion of your piston ring land separations from the piston’s side. Hence, too much blowby gas will pass through your piston. 

The best way to diagnose this problem is by conducting a compression test. When you notice that one cylinder is very low on compression, the piston may have cracked.

Read More: What Happens If You Turn Off Your Car In Drive? Surprising Facts You Never Knew!


An excessive crankcase pressure turbo problem can occur due to a number of causes. It is best to determine what is the real cause of this issue, so you can perform proper troubleshooting techniques to get it addressed and achieve favorable results.

Be sure to consult a specialist to have the issue diagnosed appropriately using the right tools. You may also do it yourself if you have diagnostic tools available, and it is best not to wait any further to prevent further problems when you delay any necessary fixes.

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