Why Does 5.7 Hemi Oil Pressure Drop at Idle? (Causes & Fix)
The standard 5.7 Hemi oil pressure should be around 20-65 psi while idle. If you have noticed the oil dropping below-recommended level, your car might have an issue!
There is no need to be worried. We will talk about every bit of detail about why hemi oil pressure drops at idle, and how you can fix it. Keep reading to find out more!
Why Does 5.7 Hemi Oil Pressure Drop at Idle?
There are a handful of reasons why a 5.7 Hemi’s oil pressure may drop at idle. Among them are clogged oil filters, low oil levels, the wrong oil viscosity, and incorrect oil viscosity.
Since the engine oil is supposed to cycle inside the Hemi 5.7, the culprit for the pressure drop can be traced back to the oil itself. However, engine issues, sensor problems, internal leakages, etc. can also cause the oil pressure in a Hemi to drop at idle.
But before you start troubleshooting, you must identify and evaluate the root cause of the problem. And to help you with that, we have compiled some of the prime causes of this issue along with the fixes.
Top 9 Causes For Hemi 5.7 Oil Pressure Dropping at Idle
Here are the top 9 reasons why Hemi’s oil pressure drops. Some reasons are easy to solve and can be done on your own, while some complex issues require assistance from professionals.
1. Low Oil Levels
The engine oil in your Hemi 5.7 engine is responsible for lubrication to reduce the wear of the engine parts. However, often leaks, tears, or deterioration of the oil container can cause the oil levels to go down.
To resolve this, first identify the reason why the oil levels fell. If the problem is related to a leak or wear, quickly resolve it and fill the tank with fresh oil.
Read Also: 5.7 Hemi Oil Pressure Problems, Oil Type & Change Procedure
2. Wrong Oil Viscosity
Your 5.7 Hemi engine may have low oil pressure at idle due to the oil’s incorrect viscosity.
If the oil is too thick, it’ll be much harder for it to lubricate the engine parts. At the same time, if the oil is too thin, it can spill out. And as we mentioned, spillage is a big reason for low oil pressure at idle.
To resolve this, simply use the right oil for your 5.7 Hemi. Experts advise using 5W-20 synthetic oil for 5.7 Hemi. You can learn more about synthetic blend 5w-20 oils here.
3. Issues With The Oil Pump
If neither the oil levels nor the viscosity is responsible for the low oil pressure, you’ll have to start checking the Hemi parts, such as an oil pump.
The oil pump helps maintain the pressure at which the engine oil moves through the engine. If the engine oil breaks or stops working for any reason, the oil pressure will drop at idle.
Engine parts all have a limited lifespan. And unfortunately, this means, a faulty engine part will need replacement. So, the only way to fix this issue is to replace the faulty oil pump with a new one.
4. Engine Sludge
Engine sludge is one of the more common reasons for low oil pressure while idle in a 5.7 HEMI. Engine sludge prevents lubrication in the engine, which can cause low oil pressure even if it’s idle.
The fix for this is to flush your 5.7 Hemi engine. You can use flushing chemicals such as Liqui-molly or Amsoil to flush the engine.
For the process, first, add the flushing chemical to the oil tank. Now, run your 5.7 Hemi engine for around 15 minutes with the chemical mix. After that, drain the engine oil.
One hack for a great engine flush is to run the engine through a clean drain with cheap engine oil. So, once drained, add any cheap engine oil to the tank and run the car for 8-10 minutes, and then drain out the oil.
You’ll notice a much cleaner oil with better color. Add the new synthetic 5w-20 oil to your 5.7 Hemi to finish up. With the sludge resolved, the oil pressure drop should show improvements!
To understand the sludge cleaning process a bit better, watch this video: The Correct Way to Flush Your Engine – Leaves No Residue – YouTube
5. Clogged Oil Filter
Oil filters are great at preventing debris from entering the engine. But your 5.7 Hemi engine may suffer an oil pressure drop at idle due to the oil filter being clogged.
This is not a big problem, as most filters eventually start clogging up. Especially if your car goes through heavy use, and a clogged oil filter can reduce oil pressure!
Replacing your oil filter is the best option, but if it’s cleanable, why not? However, the best option will be to call a mechanic.
Watch this video to learn more about bad oil filters:
Read Also: 5.7 Hemi Cylinder Deactivation Solenoid Location (The Ultimate Guide)
6. Engine Oil Leakage
As mentioned previously, leakages are one of the prime causes of oil pressure dropping at idle in a Hemi 5.7. An internal leakage will cause low oil pressure and bleed into the rest of the engine, causing other issues.
Leakages can be a headache, as the only way to fix them is through a mechanical repair. While there are some DIY methods, it’s always best to get it done professionally.
Also, if you have an older engine, it’s best to check for any leaks first. This is because older tanks deteriorate, and sometimes the oil bleeds out even without any actual leakages.
7. Issues With The Oil Pressure Sensor
A faulty oil sensor can cause the oil pump of your 5.7 Hemi to give out the wrong pressure signals. This can cause the pressure sensor to lower the oil pressure levels below what they’re supposed to be.
If you noticed your 5.7 Hemi engine drop at idle, the pressure sensor can be the reason. However, this issue is much less frequent, though it’s still a symptom!
To fix this issue, you will have to replace the oil pressure sensor. Again, there are no DIY fixes for a faulty oil pressure sensor. These components need a mechanical touch.
If you are good with tools and are planning on replacing the pressure sensor yourself, you can look for parts on Amazon. But, it’s better to get the right parts at your nearest automobile shop.
Read Also: 5.7 Hemi Oil Control Valve Location
Your 5.7 Hemi engine will eventually deteriorate. And when it does, it can cause the oil pressure to drop quite low. An old engine can come with a handful of problems, such as leakages, cam bearing issues, engine sludge, clogging, bleeding, etc.
Most of these problems can only be repaired with newer parts. As for the engine, if it’s too old, a new engine part won’t fix the issues. In this case, the engine needs to be replaced.
While costly, a replacement will work better for you in the long run. A usual repair job will only go so far. And in most cases, it’ll just cost you more money on additional repair jobs.
9. Faulty Pressure Gauge
Lastly, if your car has a faulty pressure gauge, it may show the oil pressure dropping even if it’s not! This is an issue most people face, which is why it’s better not to panic immediately.
Investing in a manual gauge is the best way to determine whether the low oil pressure in your 5.7 Hemi is being caused by a gauge issue. Attach the manual gauge and check to see if the oil pressure is actually dropping.
Read Also: Top 7 Best Oil for 5.7 Hemi Reviews & Buying Guide in 2023
How to Prevent a 5.7 Hemi Oil Pressure from Dropping?
Maintenance is the only way to stop the oil pressure in your 5.7 Hemi from dropping. Here is what you must do to prevent the Hemi oil pressure from dropping.
- Regularly monitor engine oil levels
- Ensure usage of correct oil viscosity
- Change engine oil once it goes bad
- Monitor engine oil for sludge development
- Monitor engine deterioration
- Maintain regular maintenance
Frequently Asked Questions
To round it all up, we have included a few commonly asked questions regarding today’s topic. These questions will help remove any further confusion you have about a 5.7 Hemi oil pressure drop!
Is It Normal For Your 5.7 Hemi Oil Pressure To Drop to Idle?
No, it’s not normal for your car’s oil pressure to drop below the normal amount while idle. For a 5.7, the oil will sit at around 20-60psi, anything below this is unusual for the engine.
Can You continue Driving a Car If Oil Pressure Drops at Idle?
Driving a car if the oil pressure drops at idle is not safe. The main reason is, the engine can blow out! Engine oil is essential for the engine to operate properly, and a pressure drop can cause many issues!
What’s the right oil viscosity for a 5.7 Hemi?
The right oil viscosity for a 5.7 Hemi is 5w-20 synthetic oil. The correct viscosity for your engine is essential to maintaining accurate oil pressure in your 5.7 Hemi.
The best way to avoid an issue is to maintain your car properly. In most cases, an old engine can cause Hemi’s oil pressure to drop at idle. To solve the issue, find the root cause of the problem and then choose the best way to fix it.