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Harley Oil Pressure Problems? Read This! (Help Is Here)

by

Chase Manhattan

Chase Manhattan Avatar
Owner and Editor at The Wrench Network

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Hey y’all, it’s Chase Manhattan! I’m a life-long automotive and motorcycle enthusiast with a knack for diagnostics that I hope to share with you! Lately, I’ve been running my own motorcycle rental business, which you can read about here, and it has been a great experience that has allowed me to own numerous bikes that I probably couldn’t justify otherwise. Plus, it’s been a great way to experience new places while on vacation. If you haven’t heard of them before, I definitely recommend checking out the Riders-Share platform if you get the itch to ride while away from home, or if you want to explore a cheaper way to own and ride motorcycles!

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Riding a Harley is all about that unmatched sense of freedom and the roar of the engine beneath you. But what happens when that smooth ride gets a bit bumpy, not from the road, but from something going on inside your bike? Picture this: you’re cruising along, and suddenly you notice your Harley’s oil pressure drops when it gets hot, or maybe it’s showing low oil pressure at idle. Even worse, your Harley Davidson oil pressure gauge starts giving you readings that make your heart skip a beat. Sounds familiar? No need to hit the panic button just yet!

We’ve all been there, and it’s these moments that test our bond with our bikes. But fear not, because we’re diving into the heart of Harley oil pressure problems, ready to arm you with knowledge and solutions. Whether it’s deciphering the mystery behind that dropping oil pressure when hot or figuring out why the oil pressure seems to be on a vacation at idle, we’ve got your back.

So, grab your helmet and let’s tackle these common issues head-on. With a bit of insight and the right approach, you’ll be back to enjoying that seamless ride, knowing exactly what to do if your Harley decides to throw a curveball in the form of oil pressure quirks. Ready to rev up your Harley knowledge and keep those oil pressure problems at bay? Let’s hit the road.

When Do You Most Commonly Encounter Harley Oil Pressure Problems?

A black Harley oil pressure gauge that has been damaged

There are several ways that Harley owners might encounter oil pressure problems. Some of the most common scenarios include:

  • Riding at highway speeds and noticing a sudden drop in oil pressure
  • Observing low oil pressure when idling
  • Noticing erratic behaviour from the oil pressure gauge

These problems can be alarming, especially if your motorcycle is your primary mode of transportation, or if you’re in the middle of a road trip. However, understanding the causes and solutions can often alleviate concerns. Also, as a general rule of thumb, I always recommend using the right oil for your Harley Davidson.

Your Harley Oil Pressure Drops When Hot

One common problem that Harley owners encounter is that their oil pressure drops when the engine gets hot. This can be especially noticeable when riding at highway speeds.

What Can Cause This?

Usually, this problem is caused by the oil pressure relief valve sticking. The pressure relief valve is a key component in your engine’s oil system. When it sticks, it can cause the oil pressure to fluctuate wildly. This is a notorious problem in Twin Cam engines.

Related:
> Harley Oil Breather Problems? I Have The Answer!
> Harley Breather Bypass: Should You and How?

How To Fix The Issue

One way to solve this problem is by removing and polishing the relief valve plunger until it moves freely in the cam plate bore. This simple fix can often restore the oil pressure to its normal range.

Here’s a video from a rider who was experiencing this issue. It’s a follow up video where he addressed the fixes that were necessary to get rid of the problem.

Your Harley Has Low Oil Pressure At Idle

Another common issue is low oil pressure at idle. This can be fairly normal, especially if your oil pump gears are moving slowly.

What Can Cause This?

This problem is usually caused by the slower movement of the oil pump gears when the engine is idling. To counteract this, try keeping your RPM a little higher, around 800-850.

Read next: Harley Automatic Compression Release Problems (FIXED!)

How To Fix The Issue

One solution is to simply increase your idle RPM. While the low idle might sound cool, it’s not great for maintaining oil pressure. By keeping your RPM a little higher, you can help maintain better oil pressure when idling. But most importantly, you’ll need to know how to check the oil pressure (without a gauge) in the first place. Hence, the video below:

Your Harley Davidson Oil Pressure Gauge Is Acting Up

If your oil pressure gauge is giving you problems, it can be hard to know if you’re dealing with a real issue or just a faulty gauge.

What Can Cause This?

Several things could lead to a faulty oil pressure gauge. For starters, cheap gauges are notorious for going bad. In addition, if the oil pump is worn out or failing, it can cause the gauge to give inaccurate readings.

Related: Harley Oil Light On Before Starting? I Got You Covered

How To Fix The Issue

The best solution to this issue is to replace the faulty gauge with a high-quality one. If you’re handy, you can do this yourself. Otherwise, consider taking your Harley to a professional.

When Should You Be Concerned?

If you notice any of the following signs, it’s time to take your Harley in for a professional inspection:

  • Oil pressure consistently drops below 5 PSI
  • Oil pressure fluctuates wildly
  • Oil pressure gauge is consistently giving inaccurate readings

When To See A Professional

If you’re experiencing persistent oil pressure problems or your Harley’s engine is making unusual noises, it’s best to get it checked out by a professional. They can diagnose the issue and recommend the most effective solution.

You should also know: Harley Davidson Oil Capacity Revealed (All Engines)

If Oil Pressure Problems Are Unaddressed, What Can Happen?

A Harley engine that is being completely rebuilt due to damage from oil pressure problems

Complete Engine Failure

If oil pressure problems are left unaddressed, it can lead to complete engine failure. This is because oil plays a crucial role in lubricating the moving parts of the engine and preventing overheating. Without sufficient oil pressure, these parts can wear out more quickly and may eventually fail.

Related: Harley Davidson Engine Rebuild Cost: How Much? (+Replace?)

Why? What Fails In The Engine?

The parts most likely to fail due to low oil pressure are the bearings, pistons, and camshafts. These parts rely heavily on lubrication to function properly, and without it, they can quickly wear down and fail.

Related: Harley Inner Primary Bearing Failure Symptoms? Help Is Here!

Can Positive Maintenance Prevent These Issues? (Yes and No)

Regular maintenance can certainly help prevent many common oil pressure problems. However, even with diligent maintenance, it’s possible to encounter these issues due to the wear and tear of regular use. Therefore, it’s crucial to keep an eye on your oil pressure and take action if you notice any problems. Most importantly, keep yourself educated so you can make the right decisions when it comes down for maintenance and repairs. You can do this with my technical resource documentation here:

> Torque Specs for Harley Davidson: Ultimate Guide (PDF)
> Complete Harley Davidson Tire Size Chart (PDF)

Frequently Asked Questions

What are common signs of oil pressure problems in a Harley Davidson?

Signs of oil pressure problems in Harley Davidson motorcycles typically include the oil pressure warning light staying on, unusually loud engine noise, decreased engine performance, and overheating. Oil leaks or a burning oil smell may also be noticeable.

What causes low oil pressure in a Harley Davidson?

Low oil pressure can result from a low oil level, using the wrong oil type, wear and tear of engine components like the oil pump, clogged oil filters, or leaks in the oil system. Factors such as the motorcycle’s age and high mileage can also contribute.

What is normal oil pressure for a Harley Davidson?

Normal oil pressure for a Harley Davidson typically ranges between 10 to 20 psi at idle and 30 to 45 psi at higher engine speeds. However, these values can vary depending on the model and engine type, so it’s crucial to refer to the specific guidelines in the owner’s manual.

Is it safe to ride a Harley with oil pressure problems?

It is unsafe to ride a Harley with oil pressure problems, as low oil pressure can cause insufficient lubrication, leading to excessive wear or severe engine damage. Addressing these issues immediately is vital for the motorcycle’s safety and longevity.

How do you check the oil pressure on a Harley Davidson?

To check oil pressure, use an oil pressure gauge attached to the oil pressure sensor port on your engine. Start the engine and let it reach operating temperature, then read the pressure on the gauge and compare it to the recommended specifications in your owner’s manual.

Should you add oil when oil pressure is low on a Harley?

If the oil pressure is low, first check the oil level and add oil if it’s below the recommended level. However, if the oil level is adequate and the pressure is still low, it may indicate other issues such as a faulty oil pump or clogged filter, which require further investigation.

The Harley trouble codes you should be familiar with:
> Most Common Harley Davidson Diagnostic Codes Get Explained
> Harley Code P0562 Gets Completely Explained
> Harley Code P1356 Gets Completely Explained
> Harley Code P1510 Gets Completely Explained
> Harley Code P1632 Gets Completely Explained
> The U0184 Harley Code Gets Completely Explained
> The P2300 Harley Code Gets Completely Explained
> Harley Code B2141 Gets Completely Explained
> The U0141H Harley Code Gets Completely Explained

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