Perkins 1100: 5 Causes of High Oil Consumption

High engine oil consumption in a Perkins 1100 Series diesel engine can be frustrating, especially when you have already replaced some components and the engine is still consuming oil.

One common mistake is to immediately conclude that the engine needs an overhaul.

Before removing the cylinder head or pulling out the pistons, there are several areas that deserve careful investigation.

Here are five important places to look.

1. Turbocharger

The turbocharger should be one of the first components to investigate.

A turbocharger can allow engine oil into the intake or exhaust system when its internal sealing system or bearing assembly becomes worn.

Check for:

• Excessive oil inside the intake pipe.
• Oil accumulation around the compressor outlet.
• Oil in the intercooler, where fitted.
• Excessive shaft movement.
• Signs of oil leakage on the compressor or turbine side.
• Abnormal exhaust smoke.
• Unusual turbocharger noise.

Don't be fooled by a firm turbo spindle

One important lesson is that a turbocharger spindle feeling firm by hand does not automatically mean the turbocharger is healthy.

If a Perkins 1100 Series engine has more than 10,000 operating hours, I would strongly consider replacing the turbocharger or cartridge when investigating unexplained high oil consumption, particularly when there are other signs pointing toward the turbo.

At that operating hour, the turbocharger has accumulated substantial service time, and internal wear may not always be obvious from a simple manual shaft-play check.

Depending on the condition and availability of parts, replacement can mean either:

• A complete turbocharger assembly, or
• A quality turbocharger cartridge/CHRA where appropriate.

Of course, the replacement should be the correct specification for the particular Perkins engine.

Don't condemn the engine before eliminating the turbocharger as a possible source of oil consumption.

2. Oil Rings

The piston oil-control rings have an important job: they control the amount of lubricating oil remaining on the cylinder wall.

When the oil rings are:

• Worn,
• Broken,
• Stuck by carbon,
• Incorrectly installed, or
• Unable to move freely,

excess oil can remain on the cylinder wall and enter the combustion chamber.

This can result in increased oil consumption and blue or blue-grey exhaust smoke.

During an overhaul, don't simply replace the rings and assume the problem is solved. Inspect the pistons, ring grooves and cylinder liners as well.

Carbon deposits inside the ring grooves can prevent a new oil ring from functioning correctly.

A new ring installed into a problem that hasn't been properly diagnosed can simply lead to another disappointing result.

3. Sleeves/Cylinder Liners

Cylinder liners should also be investigated when oil consumption is excessive.

A worn liner may have:

• Excessive bore wear,
• Taper,
• Out-of-round condition,
• Scoring, or
• Glazing.

When the cylinder liner is excessively worn, the piston rings may struggle to maintain proper contact with the cylinder wall.

The result can be increased blow-by and poor oil control.

This is why simply installing new piston rings without checking the liner dimensions can be a mistake.

Measure the liner. Don't diagnose it with your eyes alone.

If the measurements are outside the manufacturer's specifications, then the appropriate repair may involve replacing or machining components as permitted by the engine manufacturer's specifications.

4. Bleeder/Crankcase Breather System

Another component that is often overlooked is the crankcase breather, sometimes referred to as the bleeder system.

The breather allows crankcase gases and pressure to escape.

If the system becomes restricted by:

• Sludge,
• Carbon,
• Dirt,
• Oil deposits, or
• A damaged component,

crankcase pressure can increase.

Excessive crankcase pressure can contribute to oil being forced past seals and piston rings and can also increase external oil leakage.

Therefore, before dismantling an engine because of high oil consumption, inspect and clean the breather system and make sure it is functioning correctly.

Also check for excessive blow-by.

5. Incorrect Valve Setting

Valve clearance is another area that should not be ignored.

Incorrect valve clearance can affect the way the engine breathes and operates.

If the valve settings are incorrect, the engine may experience:

• Poor combustion,
• Reduced performance,
• Abnormal smoke,
• Hard starting, or
• Rough running.

Always use the correct valve clearance specification for the exact Perkins engine model and arrangement.

Do not adjust the valves based on memory or a specification from another engine.

The correct adjustment procedure and engine position must also be followed.

Don't Forget the Simple Checks

Before concluding that the engine requires major internal repairs, check the basics.

Look for:

• External oil leaks.
• Incorrect engine oil grade.
• Oil level above the maximum mark.
• Fuel dilution of the engine oil.
• Excessive idling.
• Incorrect engine loading.
• Engine operating temperature.
• Valve stem seals/guides where applicable.
• Excessive crankcase pressure.
• Abnormal blow-by.

Sometimes the problem is not one major component but a combination of smaller issues.

A Better Diagnostic Approach

When a Perkins 1100 Series engine is consuming excessive oil, don't start by saying:

"The rings are bad. Let's overhaul the engine."

Start with evidence.

A practical sequence is:

Check for external leaks → inspect the breather → inspect the turbocharger → check smoke and blow-by → verify valve clearance → carry out appropriate engine tests → inspect rings and liners if the evidence points there.

This approach can prevent unnecessary dismantling and save both time and money.

Final Thoughts

High engine oil consumption doesn't automatically mean that a Perkins 1100 Series engine needs an overhaul.

The turbocharger, oil rings, cylinder liners, crankcase breather and valve settings should all be considered during diagnosis.

And remember this important point:

A turbocharger spindle that feels firm is not, by itself, proof that the turbocharger is good—especially on an engine that has accumulated over 10,000 hours.

Where the symptoms and operating history justify it, replacing the complete turbocharger or an appropriate quality cartridge can be a sensible step before condemning the engine itself.

The goal isn't to replace the most expensive component.

The goal is to find the actual source of the oil consumption.

If you've worked on a Perkins 1100 Series with excessive oil consumption, which component eventually turned out to be the culprit—the turbocharger, oil rings, liners, breather system, or something else?