When considering a Melling high-volume oil pump, weighing the benefits against potential challenges is essential.
Users have reported issues like excessive oil pressure, premature bearing wear, and increased oil consumption, which can impact engine performance if not carefully managed.
However, with proper installation and attention to detail, these pumps can significantly boost your engine’s efficiency. Staying aware and proactive about these potential problems can help you get the most out of your engine and keep it running smoothly.
1. Excessive Oil Pressure
One common issue reported with Melling high-volume oil pumps is excessive oil pressure. Drivers have noticed unusually high-pressure readings after installation, which can lead to various problems, such as blown seals, oil leaks, or even damage to engine components.
This issue often occurs when the pump’s increased flow isn’t paired with an upgraded oiling system, leading to too much pressure for the engine to handle.
Some users have also pointed to the pressure relief valve not functioning properly, allowing pressure to build up instead of being regulated.
Many performance car enthusiasts, especially those with GM LS engines or Ford modular engines, have found that they need to modify the oil system or replace the relief valve to avoid these pressure spikes.
2. Premature Wear on Engine Bearings
Another problem of Melling high-volume oil pumps is premature wear on engine bearings. The high volume of oil pumped into the engine can create excessive pressure on the bearings, pushing oil out between the surfaces and reducing lubrication effectiveness. This can lead to increased friction, wear, and, in severe cases, bearing failure.
In some cases, the pump moves more oil to the top of the engine faster than it can drain back to the sump, leading to oil starvation at the lower end.
This imbalance can cause significant wear on lower-end bearings, especially in high-performance engines, where the oiling system is under greater demand.
This issue has been frequently discussed among owners of older V8 engines, particularly those who have upgraded their oil pumps without making other necessary modifications to their engine’s oiling system.
3. Increased Engine Oil Consumption
A common issue reported by users of Melling high-volume oil pumps is an increase in engine oil consumption.
High-volume pumps can push more oil to the top of the engine, which can lead to leaks into the combustion chamber, especially if the valve seals or guides are worn. This results in the oil being burned off, often visible as smoke from the exhaust.
Additionally, the excessive oil flow can lead to foaming, reducing the oil’s effectiveness in lubricating the engine. As a result, the engine may consume more oil, requiring frequent top-offs.
This problem is particularly noted in high-mileage engines or those with pre-existing issues like worn valve seals. It has been widely discussed in forums related to GM LS-series and Ford Windsor engines, where users have observed a significant increase in oil consumption after installing a high-volume oil pump.
4. Oil Pump Cavitation
Oil pump cavitation is another problem associated with Melling high volume oil pumps, particularly in high-performance engines.
Cavitation occurs when the pump moves oil faster than it can be replenished at the pickup, especially at high RPMs. This can cause air pockets or foam to form in the oil, leading to a drop in oil pressure and insufficient lubrication.
This issue is often reported in high-RPM applications, where the increased oil volume and speed create conditions for cavitation.
Users on various automotive forums have shared experiences of oil pump cavitation after installing Melling high-volume oil pumps, particularly in Ford and Chevy small-block engines.
These reports highlight the importance of ensuring the oiling system is fully optimized to handle the increased oil flow, including proper baffling and sump design to prevent cavitation.
5. Oil Pump Fitment Issues
Users who experience difficulty during installation commonly report fitment issues with Melling high-volume oil pumps.
These problems typically involve the pump not aligning properly, not seating correctly, or requiring modifications to fit within the engine. In some cases, users have encountered oil leaks or inadequate oil pressure due to improper fitment.
These issues are frequently mentioned in custom or high-performance builds, where the engine configuration differs slightly from the stock setup.
For example, users on forums like LS1Tech and FordMuscle have shared experiences of needing to modify the oil pan or adjust the oil pickup tube to ensure proper installation of the Melling high-volume oil pump.
These fitment challenges underscore the importance of careful checking and potential modifications during installation, especially in non-standard engine setups.
Conclusion
Melling high-volume oil pumps are famous for enhancing engine performance but can also have challenges. Users have reported issues like excessive oil pressure, premature wear on engine bearings, increased oil consumption, cavitation, and fitment problems.
While these pumps offer benefits, they require careful consideration and proper installation to avoid potential problems. Identifying these issues early can help maintain your engine’s health and ensure reliable performance.