Oil Gauge Going Up and Down
Chris is Head of Content for FindTheBestCarPrice and is based out of Philadelphia, PA. As a seasoned automotive industry analyst and car enthusiast, he ensures the highest level of quality across all our content and curates our picks for the best deals each month.
Chris studied information systems and marketing at Drexel University and writes about a wide range of topics ranging from car buying tips to troubleshooting common mechanical issues.
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If you've noticed that your car's oil gauge is fluctuating, going up and down, it can be a cause for concern. The oil gauge is an important component of your car's engine, responsible for measuring the oil pressure and ensuring that the engine is properly lubricated.
A fluctuating oil gauge can be caused by a number of factors, ranging from a faulty oil pressure sensor to a low oil level. The good thing is that there are some steps you can take to troubleshoot the issue on your own without needing professional help.
In this article, we will explore the common causes of a fluctuating oil gauge, including problems with the oil pressure sensor, oil pump, and engine bearings. We will also provide tips on how to diagnose the issue and what steps you can take to fix it.
This guide will teach you how to deal with the issue of an oil gauge going up and down.
Table of Contents
How Does the Oil Gauge Work?
An oil gauge is a device that gauges the pressure of oil in an engine. It comprises a dial or digital display connected to a sensor placed near the oil filter or oil pump, which measures the pressure of the oil. Typically, the gauge is mounted on a vehicle's dashboard or instrument panel.
While most modern cars have an oil pressure warning light instead of a gauge, some vehicles still have both.
Although the warning light is triggered when the pressure falls below a certain level, it does not provide a specific reading of the oil pressure. This is where the gauge comes in handy.
If the needle on the gauge indicates a reading within the normal range, it suggests that the pressure is satisfactory.
Conversely, if the needle moves towards the red zone, it is indicative of a pressure drop, and it is recommended that you pull over and turn off the engine as soon as possible to prevent further damage.
The oil pressure may drop for various reasons, but low oil levels are the most common culprit. Therefore, inspecting your oil level frequently and refilling it when necessary is crucial.
A more severe issue may be the malfunction of the oil pump, which circulates oil throughout the engine. In such cases, the oil pressure would plunge abruptly, leading to engine seizure and expensive repairs.
So, in a nutshell, how does an oil gauge operate? In essence, it calculates the oil pressure in the engine and displays it on a dial or digital screen.
By keeping a watchful eye on the gauge, you can detect any drop in pressure and take prompt action to avert engine damage.
Oil Pressure Problem vs. Gauge Problem
Although rare, dashboard gauges may malfunction from time to time. Repairing these components typically requires professional assistance and is not a typical do-it-yourself car maintenance task.
However, the data displayed on the gauge is transmitted by a simple sending unit located on the engine, and these sending units are susceptible to malfunctioning more frequently. So, how can you determine whether the gauge or the sender is at fault?
One option is to purchase a cheap universal oil pressure gauge, locate the oil pressure sending unit on the engine (the parts store may be able to assist you in finding it), remove it, and follow the instructions that accompany your universal oil pressure gauge to connect it.
Then, carefully drive the car and observe the gauge's behavior, being mindful of the road and staying focused on the gauge.
If the oil pressure reading is satisfactory and stable, replace the sending unit and drive the car again to confirm the success of the repair. A faulty sending unit typically manifests as a leak of engine oil.
What Causes Oil Gauge Going Up and Down When Driving?
Although it is not uncommon for an oil pressure gauge to fluctuate while driving, several factors may contribute to this behavior. They include the following:
1. Faulty Sending Unit
A defective sending unit is a frequent culprit for oil pressure gauge fluctuations, as it relays the correct data to the gauge. If it is not functioning adequately, the gauge will exhibit erratic fluctuations.
To rectify this problem, the sending unit must be replaced. In most cases, the oil pressure gauge sending unit is attached to the engine block through a screw.
The sending unit has a tiny tube that connects to the oil pressure gauge, which can become clogged or damaged over time, causing the gauge to give misleading readings.
To replace the sending unit, locate it near the oil filter housing on the engine block. Remove the old sending unit by unscrewing it from the block.
Subsequently, attach the new sending unit by screwing it into the engine block. Ensure that it is securely tightened without damaging the threads.
Then reconnect the little tube to the new sending unit and route it back to the oil pressure gauge.
Finally, start the engine and verify the functionality of the oil pressure gauge. If it does not work correctly, inspect all connections and ensure the new sending unit is adequately fastened.
Changing an oil pressure gauge sending unit is a straightforward process that anyone can undertake. Maintaining a functional oil pressure gauge is essential to catch any potential engine issues before they escalate.
2. Check the Oil Level
When an oil pressure gauge is going up and down, the primary step is to inspect the oil level. Inadequate oil levels may cause fluctuation; hence, verifying if the oil is low is imperative.
To do so, extract the dipstick and wipe it clean. Reinsert the dipstick and extract it again to determine the oil level.
If the oil level is low, add sufficient oil until it reaches the full mark on the dipstick. After adding the oil, restart the engine and assess whether the oil pressure has stabilized. If not, proceed to the next step.
If time is of the essence, or adding oil does not remedy the issue, proceed to the second step - investigating for leaks.
3. Oil Pump
If your oil pressure remains inconsistent after verifying the oil level, the subsequent action is to examine the oil pump.
The oil pump plays a vital role in the engine's lubrication system, and any malfunction will undoubtedly cause a pressure drop.
To assess the oil pump, you must dismount the timing belt cover and scrutinize the pump. In case any wear or damage is discerned, it must be substituted.
If no apparent damage is noticed, manually try turning the pump shaft. Any difficulty or resistance during the process might indicate a problem.
In either scenario, if you surmise that the oil pump is at fault, then replacing it is mandatory by following this guideline.
After replacing the oil pump, initiate the engine to verify if the pressure has stabilized. If the issue persists, the engine itself may have an issue and require professional scrutiny.
4. Check for Oil Leakages
If your engine is experiencing oil leakage, it could be the underlying reason for the fluctuating pressure.
To check for leaks, inspect your engine components visually and search for any signs of oil seepage on the ground or the engine itself.
Potential locations for leaks include the oil filter, oil drain plug, oil pan gasket, as well as the front and rear main seals.
If a leak is detected, promptly identify the source and take corrective action to prevent further damage to your engine.
If oil leaks are detected, refer to our comprehensive guide on fixing oil leaks. However, if you need to use your car before repairing the leak, attempt to thoroughly clean the affected area and add additional oil if required.
After rectifying the leaks, restart your engine and assess whether the oil pressure has stabilized.
If not, proceed to the next step. If no apparent leaks are detected, but you suspect a minor one may be present, directly move on to step three, checking the oil pump.
5. Blown Head Gasket
The head gasket may have blown if you're experiencing oil pressure problems shortly after an engine has overheated.
A blown head gasket can lead to the mixing of oil and coolant, as they are no longer isolated from each other.
Coolant mixes with engine oil creating foamy engine oil and causing a drop in oil pressure. Other indicators of a blown head gasket include:
- Low-pressure readings.
- Smoke is coming from the exhaust.
- A significant decrease in coolant levels.
It is essential to promptly address a blown head gasket to prevent potential damage to other engine components due to improper lubrication, heating, and combustion.
6. Faulty Pickup O-Ring
A deteriorated oil pickup O-Ring or a blocked pickup screen can lead to the pump's overexertion, resulting in decreased engine oil pressure.
Operating a car with critically low oil pressure can result in irreparable harm to the engine.
Therefore, if you detect a severely low engine oil pressure even after completing the abovementioned checks, you should have your vehicle towed to a reputable mechanic immediately.
