Testing An Oil Pan Heater: A Step-By-Step Guide

Oil pan heaters are used to warm up the engine and oil in cold climates, making cold starts easier and reducing engine wear. There are several ways to test if an oil pan heater is working, including touching it (with caution), using a thermometer, or checking the amps with an amp meter. However, some people suggest using a block heater instead of or in addition to an oil pan heater, as it warms the entire engine block and can be more effective in reducing cold start wear.

Using a thermometer to test the temperature

• Ensure the thermometer you are using is designed to measure high temperatures, as the oil pan heater can get very hot.
• Allow the oil pan heater to run for a few minutes before taking a temperature reading. This will give the heater time to reach its operating temperature.
• Place the thermometer probe or bulb directly on the surface of the oil pan heater. If your oil pan heater is inside the vehicle, you may need to locate it by feeling around the engine bay. Be careful not to touch any hot components.
• Hold the thermometer in place for a few seconds to get an accurate reading.
• Read the temperature from the thermometer display or scale.
• Compare the temperature reading to the specifications of your oil pan heater to determine if it is heating correctly.

It is important to note that oil pan heaters can get extremely hot, so always exercise caution when working around them. Do not touch the heater with your bare hands, and avoid placing anything flammable near the heater. If you are unsure about the functionality of your oil pan heater, it is best to consult a professional mechanic for advice.

Additionally, there are other methods to test the effectiveness of an oil pan heater without directly measuring the temperature. One method is to feel around the engine bay to see if the oil sump and the oil within are warm. Another method is to use a multimeter with a temperature probe to measure the temperature indirectly. You can also observe the behaviour of the oil; if it is flowing freely and reaching the top end of the engine within seconds of startup, it indicates that the oil pan heater is functioning correctly.

Testing with a finger (spitting on it first to prevent burns)

Testing an oil pan heater with your finger can be a quick way to gauge its effectiveness, but it is not without risk. To avoid burns, it is recommended to spit on your finger first. This acts as a protective layer, giving you a few seconds to touch the heater and feel its warmth before the spit evaporates. This method is also suggested for checking a running engine with a rough mag—spit on your finger and touch the exhaust, repeating for each cylinder. If one exhaust is colder, it could indicate an issue with the cylinder, plug, or lead; if they are all hot, it's likely an internal mag problem.

While this method can provide a quick indication of the oil pan heater's performance, it is not the most accurate or reliable way to test it. As one user puts it, "I always just touch mine, even right after plugging in they should be noticeably warm." However, this approach can be dangerous, as another user cautions: "I just barely touched the Reiff heater on my oil pan. Ended up with a nasty burn on my hand. My question was answered. Still can't believe that thing got so hot so quick."

Therefore, while testing with a finger can give you a general sense of the oil pan heater's warmth, it is essential to exercise caution to avoid burns. Some users suggest alternative methods, such as using a thermometer or a multi-meter with a temperature probe. Others recommend feeling around the area to assess the heater's effectiveness or using a block heater or engine cover in conjunction with the oil pan heater for more comprehensive warmth.

It is worth noting that leaving an oil pan heater on continuously may not be advisable. Some pilots choose to keep theirs plugged in 24/7 during cold months, while others only turn it on a few hours before a flight. There are concerns about the potential for burning or carbonizing the oil if left on for extended periods. Additionally, one user points out the possibility of increased moisture in the crankcase, which could lead to issues. As such, it is recommended to consult with experts or follow manufacturer guidelines for the best practices specific to your oil pan heater.

Using a Fluke multi-meter with a temperature probe

A Fluke multimeter can be used with a temperature probe to test an oil pan heater. This is how you do it:

First, make sure the oil pan heater is installed correctly. It should be attached to the oil pan with high-temperature silicone and secured with zip ties or another suitable method. Ensure the oil pan heater is plugged in and turned on.

Next, set up your Fluke multimeter. Connect the temperature probe to the multimeter, ensuring it is securely attached. Set the multimeter to the appropriate temperature measurement mode. The specific settings may vary depending on the model of your Fluke multimeter, but generally, you will want to use the temperature probe to convert your multimeter into a precision thermometer.

Now, carefully insert the temperature probe into the oil in the pan. Make sure the probe is fully submerged and does not touch the bottom or sides of the pan, as this can affect the accuracy of the reading. Wait for the multimeter to stabilise and take a reading of the oil temperature. A good practice is to stir the oil gently while monitoring the temperature to ensure an even distribution of heat.

If you need to test the oil pan heater itself, you can use the temperature probe to measure its surface temperature. Gently touch the probe to the surface of the heater, being careful not to apply too much pressure. The heater should be warm to the touch, but not excessively hot. If it is not warm, there may be an issue with the heater or its electrical connection.

Finally, compare your temperature readings to the expected values. If the oil temperature is within the desired range, your oil pan heater is functioning correctly. If the temperature is too low, there may be an issue with the heater's wattage or its placement in the pan. If the temperature is too high, the heater may be faulty or set too high, which could be dangerous.

Remember to exercise caution when working with hot oil and electrical equipment, and always follow safety guidelines provided by the manufacturers of your oil pan heater and Fluke multimeter.

Checking for a strong smell of oil

If you smell oil, it's a good idea to have a trained technician come and inspect your heating system and oil tank. While heating oil fumes are not as dangerous as gas fumes, they can still cause health issues, especially in enclosed spaces, and the issue should be resolved as soon as possible.

A strong smell of oil could indicate a problem with your furnace or heating system. For example, if your furnace is not operating efficiently, some of the oil might not be combusting fully, and the leftover oil can cause a strong oil smell. There could also be a crack in the oil burner, allowing oil fumes to escape. If you think your furnace is not operating correctly, you should have an HVAC technician come and diagnose the problem.

Another possible cause of a strong oil smell is a leak in your oil tank. The location of the tank will influence the strength of the smell. If the tank is indoors, you are more likely to notice a stronger smell compared to if the tank is situated outside. In the case of an indoor tank, you may see a dark area on the floor underneath the leak. If your tank is outdoors, you may notice that grass or vegetation around it looks dry or dead. If you suspect a leak, contact a technician immediately to have them assess the situation and determine whether a repair or replacement is required.

If you have recently had your tank refilled, it is normal to notice a slight smell of oil for a few days afterward. This could be due to a small amount of oil that spilled during the refill process, or some errant fumes escaping before the lid was put back on. However, if the smell doesn't go away on its own, it could indicate a more severe issue such as a spill.

Testing the amperage with an amp meter

• Prepare the Multimeter: Before you begin, ensure that your multimeter is rated for the amperage you'll be testing. Check the maximum amp rating, which is usually printed on the back of the multimeter or in the instruction manual. Also, verify the ratings of your power source by checking the device's nameplate.
• Insert Leads: Insert the red lead (positive probe) into the amp (A) terminal, and the black lead (negative probe) into the ground (COM) terminal. The "COM" port is common to all measurements, so it doesn't need to be moved.
• Set the Meter Type: Determine whether you're working with an AC (alternating current) or DC (direct current) circuit. Set the meter to the appropriate type—AC or DC. On some multimeters, you may need to push a button to switch between AC and DC.
• Configure the Amperage Setting: Turn the rotary dial to the amperage setting that corresponds with the socket you're using. If your multimeter has individual "A" and "mA" settings, select the one that matches your socket. If there's a single "A" setting, choose that option.
• Connect the Multimeter in Series: Create a break in the circuit by disconnecting the positive wire from the power source. This is typically red. Do not cut the wire; instead, look for a cap where the wire from the power source meets the wire going to the device, and unscrew it to separate the wires. Now, connect the red probe of the multimeter to the positive wire coming from the power source, and the black probe to the positive wire going to the device. This completes the circuit.
• Power the Circuit: Ensure the power to the circuit is turned off before connecting the meter. Once the multimeter is connected, turn on the power to the circuit.
• Take the Amperage Reading: The multimeter will display the amperage reading immediately. However, for the most accurate measurement, leave the probes in place for about 60 seconds to ensure a steady current.

It's important to prioritise safety when working with electricity. Always wear protective gear, such as rubber gloves, and avoid working near water or on metal surfaces. Additionally, have someone nearby who can assist in case of an emergency.

Frequently asked questions