How Oil Sludge Can Cause Engine Failure

We do a lot of oil changes at Carolina Auto Service. Engine oil is a brown, free-flowing liquid. This vital fluid has one purpose: to ensure no contaminants get to the engine and cause damage. 

The blend contains additives to help it stay clean while on the roadways, but the oil should never have dirt, water, or coolant mixed in it. We see many customers who’ve experienced premature engine failure, and most of the time the oil has turned to sludge. 

The once brown fluid has now turned into a black goo that’s caused permanent damage. When oil meets dirt and other contaminants, it breaks down. Rather than flowing freely, it turns into a thick soup-like consistency. When you have sludge running through your engine, the damage is unavoidable. 

The Chemistry of Oil’s Decomposition Process

Remember those long science classes where you learned about decomposition and stabilization? Your oil and its overall breakdown are chemistry, and the process is called oxidation. You must change your oil because, at high temperatures in the engine, the oil naturally begins to break down or decompose. 

The excessively high temperatures accelerate the process, as is between 220-250 degrees. When the oil breaks down, the molecules within the oil break down. The products in the oil turn into a solid structure, which contains dirt, metal, and sometimes coolant. When our technicians see sludge in the engine, they can tell much about the vehicle. 

During an oil change, the oil is drained from the crankcase. You can quickly identify oil that’s been contaminated and has gone through the oxidation process. Some oils have significant oxidation while others have minor. If the oil is healthy, it will maintain its brown hue and remain free-flowing.

Why You Have Sludge Deposits in Your Engine? 

There are a few reasons you might have sludge deposits in the oil, and it’s not always because you haven’t changed it correctly. While that’s undoubtedly one of the first things we consider, oil does tell other stories. Here are some other things to consider. 

1. Stop and Go Driving

Stop-and-go driving is always harder on your engine than taking the freeway. Many advertise their vehicles for sale, claiming “highway miles.” The rationale is that a car constantly moving doesn’t have oxidated damage to the engine and oil from the start and stop driving. So, a vehicle that drives mostly inner city would likely have more oxidation than one that travels the open roadways. 

2. The Engine is Running Hot

Since heat accelerates the oxidation process, an engine running hot can cause oil to turn into sludge. People who see their car is overheating and still drive it runs the risk of having their oil burn and turn to sludge. 

3. Inferior oil

Some oils perform better than others. Remember the old saying you get what you pay for in life? It certainly applies to your oil. High-performance oils and synthetics always fare better than others. While oil bases have improved, there’s always a reason to get high quality. 

4. Contamination by Coolant

The coolant can make its way into the oil chamber and cause contamination. When we see this, it’s an indication of significant trouble. There’s either a blown head gasket or a damaged cylinder head, which are expensive to repair. These issues usually don’t have anything to do with maintenance, as any car can blow a gasket, but it can come from running a car too hot and not maintaining it. 

Signs Your Oil is Contaminated

Whether you change the oil frequently or not, there are some signs of trouble with this vital fluid. Here are some of the most common ones. 

•Low oil pressure – The light on your dash will illuminate as the pressure inside the engine is not optimal. 

•Clicking sounds – The oil struggles to make it through the engine, so you will likely hear unusual noises from the tappet as it attempts to pump. 

•Draining issues – When your mechanic tries to drain the oil for an oil change, it’s a slow process. Sludge takes much longer to drain than free-flowing oil. 

•Contaminated filter – Another thing that we often see is a contaminated oil filter. If there’s grease on this filter, it’s an indication of an issue.

The Importance of Regular Oil Changes

Our experienced technicians know that when they see oil resembling thick molasses, it indicates a severe problem. We also understand that not all sludge issues come from a lack of maintenance and neglect, but we do diagnostics to pinpoint the cause. 

It’s imperative to ensure your engine oil is changed according to your oil specifications. No engine should ever go over 10,000 miles, and this is with high-grade synthetics. Most engines require it to be changed every 3,000-5,000 miles. How long has it been since your oil’s been changed? Call today for an appointment.