A rattling engine can be very disturbing. If your Subaru Liberty is experiencing this problem, we’ll cover the most common causes. A rattling engine can be caused be the exhaust, timing chain, loose accessories, and much more.
Engine Rattling Causes: Subaru Liberty
Here are the most common causes of a rattling sound in your Liberty:
Exhaust
The exhaust system is one of the most common culprits that can make it sound like your Subaru Liberty’s engine is rattling. While the exhaust is outside of the engine itself, it can often cause sounds that are confused for an internal engine rattle.
Heat Shield
The number one rattling culprit in your Liberty’s exhaust system is the heat shield. They can get a little loose as the vehicle ages and accumulates mileage. Once this happens, it’ll rattle all of the time. It’s particularly noticeable when you rev the engine in neutral and let off of the gas pedal. You should hear a rattle as the engine comes back down from the higher RPM.
If the heat shield is loose, you’ll need to take your Liberty into a good exhaust shop and have it welded back into place. The good news is that a loose heat shield is never going to leave you broken down on the side of the road.
Exhaust Leak
If your exhaust system is leaking, it will often make an aggressive ticking sound. Some folks have described it as a rattle. If it is leaking, the most common place that it leaks from is going to be where it bolts to the block at the exhaust manifolds. You can check and see if any of the exhaust manifold bolts have broken off. This is very common in all vehicles.
Catalytic Converter
The catalytic converter is responsible for scrubbing the majority of the pollutants out of your exhaust. As it ages, the metals inside can break down. When this happens, you can hear them rattle around.
When the catalytic converter does fail, it’ll often give you code P0420, or P0430. If your check engine light is on, you may want to see if you have an emissions related code. That would be very strong evidence that the catalytic converter is causing the problem.
Most auto parts stores are happy to scan your codes free of charge. Otherwise, scanners are really cheap.
Timing Chain
A loose timing chain can really make a rattling sound. This sound is particularly noticeable when you start the Liberty. A bad tensioner will leave the chain loose and ready to jump a tooth or fall off all of the way. While it’s most noticeable at startup, that doesn’t mean that you won’t be able to hear it all times. Sometimes you can, sometimes you can’t.
Loose Accessory
If something has worked its way loose on your engine, it can rattle and dance at different RPMs. If you’ve left your oil cap loose on top of the valve cover, that can cause a rattling sound. Or, if you’ve left a tool on top of the intake or valve cover it can cause a rattling sound. It doesn’t even need to be something loose, it can just be out of place.
Oil
This seems obvious, but it’s worth checking out. If there is no oil in the crankcase, the engine is going to sound like a rattling old buzzsaw. That rattling sound is the sound of your Liberty’s engine dying.
If you have a blown head gasket, you could be losing water that goes into the crankcase. When this happens the oil loses its viscosity as it is watered down. The oil will look orange and foamy when this is the case.
Internal Engine Issue
If you’ve been looking for all of the issues described above, it could be that there is something inside of the engine that is making it rattle. You could have a stuck lifter, a burnt valve, the wrong spark plugs, or more. Hopefully, one of the easier to fix and more common issues listed above though.
Conclusion: Liberty Engine Rattling
Good luck fixing the rattle coming from your Subaru Liberty. If there is anything that you would like to add, please leave a comment below.