Engine Sludge: Creature from the Dark Lagoon

Welcome to texas-cars-and-dealerships in-depth coverage of the engine sludge debacle.

This is an extensive piece, spread out over several web pages, but I recommend reading the entire section now because you never know when this depth of information could come in handy.

Cocktail party conversation could drift to motor oil sludge and you'll be the goto person.

Or perhaps you already own, or might inadvertently purchase, one of the engine sludgers discussed here.

Many people think oil sludging in auto engines is "old news." I say it is one facet of an ongoing situation.

I prefer to analyze the oil sludge problem as part of a larger engineering crisis in the auto industry, rather than a single manufacturer's shortcoming or short-term aberration.

Thousands of car owners have been victims of engine oil sludging, also known as gelling.

Toyota, Chrysler, Volkswagen, Audi, Dodge, Saab, and Lexus all built engines more vulnerable to sludge than the average.

Sludgers sold in 1998, 1999, 2000, 2001, 2002, 2003, and 2004 are still on the street.

As I write, in April, 2008, fresh news stories of used cars whose engines blew, because of lubricant sludge, are still coming out.

Many times purchasers thought they had "stolen" the car because the dealer/seller seemed so willing to compromise on price.

While the oil gelling debacle is behind the new car business now, there are lessons for car consumers (everybody) in the story.

The main one is that naive car buyers, whether new or used, are asking for big trouble. Let's not join them.

Overnight Success: Sludge History

Sludging of lubricants is a not new engineering problem.

Railroads of the 19th century experimented with oiling techniques, since overheated wheel bearings were a common problem. Train crews got out at each stop, oiled the drivers, and checked all the wheel bearings. Occasionally a "hot box" would sludge its lubricant.

In the early years of the automobile, mechanics routinely dropped oil pans and cleaned motors with kerosene.

Commercial truck engines operated for a million miles will exhibit every oiling failure imaginable.

In aviation, sludge inside newly designed feathering propellers was a serious issue in the 1930s. Turbine powerplants in modern aircraft subject oil to extremes beyond the ordinary automotive application.

Ford put out a Technical Service Bulletin (TSB) on many 302 V-8 engines from the late 1980's. The TSB included the phrase "oil sludge build-up.....may occur on engines that have as little as 30,000 miles."

Taxi fleets, police, and urban delivery operators learned about oil sludge the hard way decades ago. These fleets change oil after as little as 1,000 miles.

So there was plenty of precedent when oil gelling problems "suddenly" appeared around the turn of the 21st century.

Sludged powerplants are not confined to one manufacturer's products, as some critics imply. But some motors, 4.7 million engines sold in the U.S., exhibit higher risk for developing oiling issues.

Sludge problems are caused by a combination of defective engine designs, "maintenance free" marketing that resulted in overly ambitious recommended service intervals, and inadequate maintenance in many forms.

Engine oil gelling is a big-ticket repair item, like $3,000 to $9,000, with a high secondary failure rate. Even one delayed oil change can result in a high dollar disaster, often for a subsequent owner.

If an engine is built sludge prone, and allowed to start gelling up, there is no easy solution. Some new car buyers paid for rebuilt engines three or more times in the first 100k miles, as warranty claims were repeatedly denied.

Some people even refinanced a rebuilt engine to keep their job critical transportation alive, only to have it sludge and fail again.

What is Oil Sludge?

Sludge is thickening, moisture and contaminant build up, and eventual hardening, as motor oil ages.

Sludged petroleum is a thick, dark slime that accumulates when oil's molecular structure changes and the additives are used up. The goo precipitates on internal surfaces, clogging the engine's oiling system progressively, despite oil changes. In a sludge-prone engine, once the process is started, it snowballs.

Different "types" of sludge may evolve, depending on the contributing causes and length of exposure.

A continuum of possible end products exists, from varnish to gel.

At one extreme, dry varnish is reddish-brown to black film deposits baked-on interior surfaces.

Gel, an emulsion of oil with water or antifreeze that is semi-liquid, but has become too viscous to flow properly, can be visualized as the other end of the sludge spectrum.

Once sludge has taken over, gummed-up oil passageways, called galleries, in the engine block and head deprive critical motor parts of lubrication.

The engine oil gelling problem is often compared to human cardiovascular disease: hardening of the arteries in a car's motor.

When oil arteries are sludged, engine failure will follow.

This is why every oil change is important, once the galleries and other small apertures are closed, going back to the proper maintenance schedule won't desludge the motor.

A National Highway Traffic Safety Administration (NHTSA) investigation did not result in an oil sludge recall. No safety issue was found.

For manufacturers, recalling millions of clean engines to look for those few that sludged was not a practical alternative.

Black Sheep: How Common is Engine Sludge?

Just how common is a sludge damaged engine?

We'll never know how many sludge complaints have been made.

Automakers tend to report only written claims, and naturally don't use high profile news outlets for this embarrassing data.

Toyota admitted they received 3,400 engine oil gelling complaints prior to extending vehicle warranties on 3.3 million at-risk vehicles in 2002.

Toyota's quality leader reputation took a big hit as a result of building sludger motors. Angry consumers fought back, with petitions and class action lawsuits.

But let's try to stay objective.

Nobody was killed, additional environmental damage has not occurred.

The number of engines affected by sludge is relatively insignificant compared to the total number of motors built. For instance, of the three-plus million Toyota engines that are "affected," I estimate 10,000 have experienced failures related to oiling issues.

The majority were used cars, operated by second or subsequent owners.

That is slightly over two failures per 1,000 engines. Toyota mills that gummed up while still under warranty were a fraction of the total.

So the oil sludge problem is rare, affecting only about 1% of the sludge-prone motors. But premature catastrophic engine failure, the common result, generates some seriously irate consumers.

A little research, both by builders and consumers, could have prevented most of the problems.

Who's To Blame?

Automakers resisted sludge based warranty claims, insisting only poor maintenance could cause gelling. They shifted the blame to consumers.

So a real catfight developed, with car owners, class action lawyers, manufacturers, California's Attorney General, and oil companies in the action.

Forum posts, sometimes a source of decent quality information, have gone up in flames as shills for competing interests threw sticks-and-stones.

This polarized the issue, making either flawed engineering or improper maintenance "the sole cause."

With so many engaged in cover-up, blame-casting, and accusation, no consensus evolved in the industry on a solution the sludge problem.

Builders looked for scapegoats further down the pyramid to shoulder the cost burden, and instead of recalling the engines they extended warranty while raising barriers to claims.

Meanwhile, their engineers quietly redesigned the flawed engines.

Despite the engineering gaffes and poor customer service performance of automakers, the reality is that a majority of the engines sludged were improperly maintained at some point in their history. This made it easy for manufacturers to deny legitimate claims from owners who had fastidiously changed lubricant on schedule.

Warranty Welchers

Stories of stonewalling, warranty claim denials, and obtuse customer relations accompanied the oil sludge debacle.

Anybody can make a mistake, but outright lying destroys customer relationships.

Dealers were caught in the middle, and despite some heroic efforts, generally went along with the cover-up.

Toyota, Volkswagen, Saab, and Audi, eventually offered extended engine warranties on cars prone to oil gelling.

DaimlerChrysler continued to deny there was even a problem, and denied most warranty claims.

Mean mileage of engines damaged by oil sludge is just over sixty thousand. Some new motors bit the dust with as little as fifteen thousand miles.

A majority had low enough miles to qualify for warranty repair, but owners who couldn't produce documentation for every recommended interval oil change got rejected.

Receipts for oil and filters purchased by do-it-yourself types were deemed unacceptable as proof of oil changes.

Symptoms of a Sludged Engine

There are no absolute indicators of oil sludge. You have to open up the engine, removing valve covers or oil pan to see it.

Signs and symptoms of oil gelling might include white or blue smoke after cold starts, and during acceleration. This can be caused by hardened, cracked, or shrunken valve seals allowing oil to run down into the combustion chamber.

A sludged motor could need more frequent EGR and PCV valve replacement. Oxygen sensors and catalytic converters may go bad prematurely.

Emissions test failures are common in sludgers.

Excessive oil consumption alone is not necessarily indicative of sludge, but if accompanied by lubricant color change to a burnt brown-red prior to reaching recommended oil change interval, further investigation is advised.

Ordinarily oil ages from a nice golden color to a sooty black by change time.

Examination of used oil filters can reveal clues to internal engine conditions. Metal particles or frothy white gel in the old oil filter are tip-offs.

Sometimes there is nicotine-like staining on the dipstick.

Some engines can be inspected by removing the oil filler cap and shining a flashlight into the valve cover. Other motors have baffles that prevent a visual inspection.

When vision through the filler neck is blocked, some mechanics will make a scraper of old wire - a coat hanger will work - and snake it through the oil filler to retrieve a sample from the valve train or head.

Some will insert the wire up through the oil pan drain aperture, but this is more difficult.

If gel comes out on the probe, further inspection will be suggested.

Submitting a lube sample for oil analysis could prevent a nightmare.

Mail in motor oil analysis kits are sold on the web around $15.00.

Petroleum experts routinely use oil analysis for commercial diesel truck engines.

Lessons from the Engine Sludge Embarrassment

1. To me the most important thing about the sludge foul-up is that car buyers must do better research before jumping into these dangerous waters (ahem, my site theme).

2. Industry-influenced web sites and hard copy mainstream media cannot be counted on to report issues like motor oil sludge.

3. Consumers who fail to acquire minimum mechanical knowledge will inevitably be victims.

4. When a serious issue arises, manufacturer and dealer personnel will not necessarily be forthcoming - many sludged motors were ignored by shops until warranty had expired, thus reducing claims.

5. Do-it-yourself means you will always work outside the warranty framework.

6. Every receipt, with date, mileage and VIN clearly legible, should be retained as part of the car's resale/trade/warranty file.

   A used car is much more valuable when accompanied by a clean CARFAX report, original new car sale documents, and a complete maintenance history showing on-time oil changes.

   If the above are not provided, is it really a "one owner car?"

7. Vehicle maintenance is mandatory, it is not the vendor's responsibility. Many owners of sludging engines will say "but it was just in the shop last week." Shop personnel will not perform sludge checks unless authorized.

8. Fast lube outfits are be hazardous to your car's health.

9. Do not drive with an overheated engine.

10. Never drive even one quarter mile with an oil light on.

Favorite Forum Quotes

"just report your car stolen"

"Dodge Stratus, bought new in 2001, ...is now a driveway ornament"

"I now own a planter"

"I thought that I just had some bad luck, so I bought another one... (Dodge Intrepid)"

"...sludge can actually be a GOOD thing. Helps boost the oil pressure and plugs the leaks"

"I'd buy a Yugo first""

"I will slowly cut up the whole car
and put it in the trash a little at a time."

"Preventive maintenance is the answer to the longevity of any vehicle."

Desolation Row: Sludge Prone Motors

Think twice when you see a vehicle on this list auctioned with "no reserve" on eBay.

CHRYSLER;

Over 750,000 1998-2002 Dodge and Chrysler vehicles with Mitsubishi-designed 2.7 liter DOHC V6 engines are engine sludge prone.

Including;