The Truth About Cars » Sludge The Truth About Cars is dedicated to providing candid, unbiased automobile reviews and the latest in auto industry news. Thu, 17 Jul 2014 12:00:21 +0000 en-US hourly 1 The Truth About Cars is dedicated to providing candid, unbiased automobile reviews and the latest in auto industry news. The Truth About Cars no The Truth About Cars (The Truth About Cars) 2006-2009 The Truth About Cars The Truth About Cars is dedicated to providing candid, unbiased automobile reviews and the latest in auto industry news. The Truth About Cars » Sludge Piston Slap: See the USA in your K-I-A? Mon, 11 Nov 2013 12:50:06 +0000

Phil writes:

Hello Sajeev,

I have a question related to maintenance on a 2011 Kia Optima SX Turbo. It currently has 45k miles, and I have owned it for only 4 months (had 20k when I took ownership of it). As you can see, it is driven a whole lot, almost exclusively on the great interstates of the Southeastern US of A. I average 5-6k per month. I am an outside sales rep. and drive from SC to MS and everywhere in between weekly.

My question is this:

Should I follow standard maintenance routines, such as every 5k oil changes and manufacturer’s recommended filter, plug and fluid changes; or can I extend these intervals. If so, how much can these intervals be safely extended? I plan to keep the car for about 3 years or 200k miles if it continues to run as well as it has. Are there any tips to keep the car in top shape mechanically?

Sajeev answers:

The gray area in these situations might as well be the entire discussion: Black and White analysis goes out the window! Some salient points, no matter the vehicle:

  • You can kinda, sorta judge oil condition yourself because worn out oil has a different look (not golden), feel in your fingertips (sinks into your fingerprints) and smell (like a BBQ gone bad).
  • Turbocharged cars demand more from their motor oil.
  • Turbocharged cars with marginal oiling systems (and cooling?) break oil down faster than similar systems. (see VW/Audi engine sludging)
  • Many wear items are indifferent to the frequency of driving and driving conditions (highway, vs. city) so you cannot significantly deviate from their service intervals.

In the case of a Turbocharged FWD family sedan with limited real estate for intercoolers/oil coolers/etc, I default to the worst case scenario: a sludge magnet like an older Audi.  Stick with 5k oil changes, unless you spend the money for an oil analysis to see exactly how (or at what rate) your driving style breaks down oil. Switching to a full synthetic extends the life of the motor and possibly the service cycle…but I ain’t committin’ to nothin‘ without an oil analysis.

What about other non-engine oil items?  Filters, coolant, spark plugs, should be replaced at the same intervals, unless you switch to a K&N air filter…which actually makes sense in your case! The only wildcard for me is the transmission fluid: one person putting that kinda time on the Interstate drastically alleviates stress on your ATF.  If three years is all you need, you may never need to change the transmission fluid.  BUT…since we aren’t in the business of abusing cars here…assuming there’s no dipstick to check, odds are servicing every 100k-150k is more than adequate.

I hope you enjoy this machine, as the Optima Turbo is on my short list of super cool machines for the average person.  I’d love to own one someday, but perhaps you should visit Steve Lang in ATL when you are ready to sell. He’ll make you the best deal when it’s “Hammer Time.”

Send your queries to Spare no details and ask for a speedy resolution if you’re in a hurry…but be realistic, and use your make/model specific forums instead of TTAC for more timely advice. 

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Biodiesel From Sewage Is Cheaper Than Ever Sat, 01 Sep 2012 13:00:01 +0000 Click here to view the embedded video.

It’s not often publicly remarked upon, but the emphasis on biofuel capacity in the United States has a bit of an international political component to it. American farms exported well over 100,000 metric tons of corn and oilseed in 2010. Some major portion of that production was sent to oil-rich areas which are short on food. The E85 boondoggle can be viewed as a simple declaration to those nations: we can burn your food in our cars, but you can’t eat your oil.

America’s pretty good at producing another item besides food, however, and if early research is any indication, it could be used to run a significant portion of the nation’s car and truck fleet.

According to an article in Chemical & Engineering News, a new process developed by a team led by South Korean scientist Eilhann Kwon makes it easier to extract lipids from… well, you know:

Kwon and his colleagues found a cheaper feedstock for biodiesel production: sewage sludge, the semisolid material left over from wastewater treatment. This sludge is a rich source of lipids, the starting material for biodiesel. Most of sludge’s lipids come from bacteria living in it.

Kwon and his team used n-hexane to extract lipids from sludge pellets from a wastewater treatment plant in Suwon-City, South Korea. Compared to published yields of lipids from soybeans, the sludge produced 2,200 times more lipids per gram of feedstock. Sewage sludge is also a cheaper lipid source than soybeans, Kwon says. Each liter of lipids that the researchers extracted from sludge cost $0.03, while previously published data shows each liter from soybeans costs $0.80.

However, impurities including free fatty acids in the lipids extracted from sewage sludge would interfere with the conventional catalytic process for making biodiesel. So Kwon’s team developed a noncatalytic method that would work in the presence of free fatty acids and other impurities in the feedstock…

To test their idea, the team continuously fed methanol and the extracted sludge lipids into a reactor containing porous activated alumina and heated the reactor to 380 °C. Adding carbon dioxide to the reactor improved the reaction’s yield. The researchers’ method converted about 98% of the sludge lipids to biodiesel.

And there you have it. There’s nothing new about the idea of converting sewage sludge to energy: see this article for an early set of ideas on the topic. Furthermore, sewage sludge already has a cash value: you may be eating some of it right now. This new process maximizes the biofuel return, however, and makes it an attractive choice for future energy.

Will the day come when solar-powered home centrifuges generate biofuel from every toilet in the household? Well, it’s certainly no less likely to happen than, say, a national power infrastructure that would allow everyone in America to charge their Volt or Leaf on 220volt juice without browning-out the whole country every evening.

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How To Buy A Used Car Part Two: The Test Drive Thu, 09 Aug 2012 16:59:50 +0000 Picture Courtesy of

[Editor's note: Part One of Steve Lang's updated guide to used car buying can be found here]

Schedule the test drive for a time when there’s no rush. If it’s bad weather, reschedule.

Take a little notebook, write a quick check list based on this article, and make notes.

When you approach the car’s owner, be friendly, polite and courteous. Do NOT try to “beat them down” to get a better deal on a test drive. Ever. While you have every right to ask direct questions, you have no more right to insult their car than one of their children.



Open the hood and look at five big areas. Oil dipstick, coolant, power steering fluid, radiator cap and brake fluid.

Oil: Golden brown, light tan, a little dark, or even dark brown to light black are fine. The oil is just doing it’s job. A tar color or tar like consistency is not good.

Check the dipstick for level and color. Then check the oil cap on top of the engine (on most models) for anything that resembles milky crud. If it has a thick film of milky crud, that’s engine sludge, you’re done.

Coolant: Check the coolant reservoir for level. Most sellers pay attention to this. But a few don’t. Remove the radiator cap if it’s accessible. If you see crud on the cap, you’re done.

Power Steering and Brake Fluid: Check for the level. In the case of power steering, check for any heavy leakage around the hoses. If the power steering hose is saturated with oil, this could be a sign of a more expensive repair in the times ahead. Make a note of it.


The Tires And Body

Tires: First, check the tires. Pull the steering wheel all the way to the left (and then right later on) so you can see the entire tread. Uneven tire wear– marks on the side or deep grooves in the middle– may indicate suspension issues. And nothing screams “lemon” louder than cheap, bald or strangely worn rubber.

Doors: Next, open and close all the doors several times, including the trunk and hood. This will also give you the opportunity to inspect the seats and floor. On the doors, check for paint on the hinges and black moldings. If a door creaks, it’s usually no big deal. If a door has trouble closing, make a note of it if you later chose to have the vehicle inspected. It can signal anything from a broken hinge to frame damage.

Panel Gaps and Trunk: Have a quick look at the panel gaps, especially the hood and trunk. Unless you’re looking at an old Land Rover, they should all be even. Check for water leakage in the trunk. Damp and/or a mildew smell often indicates problems underneath if you live in an area where rust is an issue. Lift the trunk’s carpet and see if there is any water or damp residue underneath.


The Interior Features And Lights

When you climb aboard, don’t be put off by worn seats or busted radios. Most interior surfaces and parts can be repaired or replaced easily and cheaply.

Windows: Lower each of the windows first while the key is at the ‘on’ position, and fire up the car.

Engine: Do you hear any tapping or pinging sounds, or does it kick over with a smooth ‘vrooom’ and settle into an easy, quiet idle? Start it up again if you aren’t 100% sure.

Buttons: Test all the buttons and switches including the radio stations. Ask for help and have the owner turn on the ‘left’ signal and look at the front and rear to make sure the bulbs work. Repeat with the right.

Exterior Lights:  Then check the headlights along with the brights. Brake lights should be checked in the rear as well as reverse. This may be your only time to verify their proper operation before owning the vehicle. So take the time to do it.

Windshield Wipers and E-Brake: Finally have the fellow spray their windshield and make sure the wipers are in good order. Thank them for helping them you and then test the emergency brake to ensure that it’s operating properly. If you’re driving a stickshift you will want to do this later in the test drive on a steep upward incline.

Air Conditioning: Flip on the A/C. It should kick out cool air within fifteen seconds. With an older vehicle the performance of the A/C system should be one of the more critical concerns. (HVAC repairs can run as high as $500 to $1500.) When you’re on the road, test the heat and the A/C again to make sure the temperature and fan speed are constant.

Power Steering: Finally before going on the road lower your windows and turn the steering wheel all the way to the left and right. The motion should be seamless and silent. If there’s a lot of resistance, or the force required is uneven, the steering system may need anything from power steering fluid (cheap) to a power steering pump assembly (moderate) to a new rack (first born). Make a note of it.


The Drive

Shift: Now put the car in gear. Aside from a few models (older Mercedes in particular), a late or rough shift from park indicates that the car’s transmission may soon give up the ghost. If you experience very rough or late shifting, you’re done.

Brakes: Brake force should be quick and constant. Unless the brakes have been recently replaced (ask), you shouldn’t hear any squeaking sounds. Keep the driver’s window open during the first half of the drive.

Transmission: Drive the car through a variety of traffic conditions, inclines and speeds, for at least fifteen minutes. When going uphill, take your foot off the accelerator for a moment. Coast downhill as well. If the car’s transmission hunts, clunks or has trouble catching, the vehicle probably has a transmission or linkage issue. Make a note of it.

Engine: If you hear a lot of ‘clacking’ or other unusual engine noises on initial acceleration, the engine’s components may need attention. If there’s an oil gauge, keep an eye on it. It should show approximately 25 to 80 psi during acceleration, and 10 to 20 when idling. The coolant temperature gauge should hit a fixed point within ten minutes and never move.


Quick Stop

After about twenty minutes of driving, take the car to a gas station. Keep the engine on.

Gas release: Open the hood and the gas cover release to make sure they’re in proper working order. I also take this time to put $5 of gas in as a goodwill gesture.

Most folks will not have a car buyer as studious as you, and it’s nice to reimburse folks for an expense.

Transmission Fluid: Restart the car. If you know where the transmission dipstick is (and it’s a damn good idea to find out), check the level and color. Does it have bubbles? If the fluid is very dark brown or black, or smells burnt, it could be a sign of future transmission issues.

Final Oil Check: Turn the vehicle off and again, check the oil. If it’s not between the marks (too low or too high), or if the oil cap is milky brown, you’re done. I’ve dealt with more than a few cars that had their oil caps wiped clean before the test drive.


Last Inpsection And First Decision

After leaving the gas station, see if you can find a nice open parking lot or area where you can do a few ‘figure 8’s’.

CV Joints: Lower the windows and turn the steering wheel all the way to the left. Drive very slowly and see whether you have any ‘clicking noises’ near the wheels. If it does, you will likely need to have the CV axle replaced on that side. Now turn it all the way to the right side and repeat. The turns should be ‘click’ and noise free.

Decision Time: By this point, you should have a pretty good idea whether your next step is towards purchase or home sweet home. If you’re blowing it off, thank the owner politely and leave promptly, without engaging in any further discussion whatsoever. (“It’s not what I had in mind.”) Show them the gas receipt as a goodwill gesture and thank them.

If you’re ready to move forward, it’s time to schedule a professional inspection.

[Mr. Lang invites TTAC readers to share theirused car test drive advice below. He can be reached directly at]

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Piston Slap: Too Cool, or Dex-Cool? Mon, 06 Aug 2012 11:57:31 +0000  


Nate writes:

Ok, you asked for input and I’ve got a question about my 2003 Cadillac CTS. I figure I’m more likely to get a reliable answer from you and the best & brightest of TTAC than the goof balls at Car Talk (this letter is from February-SM), so I’ll ask.

I bought this CTS back in November. It had 135,000 miles on the odo, came from a private owner and apparently had significant engine work accomplished a year or so ago apparently as a result of a timing belt failure after it wasn’t replaced on schedule. Before being able to get the car licensed, I paid to have the thermostat and temp sensor replaced as I had a CEL and a P0128 code and the car wouldn’t pass inspection with a CEL code. The code came back after just about 1 week.

The CEL will clear if the ambient temps move up above 45-50 degrees but returns when the temps get back down to Utah normals for winter. I’ve been unable to find an online solution. I’ve considered installing a temporary partial radiator block, (cardboard & duct tape) to see if that old school fix brings the temp up. The car doesn’t have a temp gauge- thanks for nothing GM; but seems to warm up the cabin appropriately if not exceptionally fast.

Am I going to have to reset the codes each December before taking this in for emissions inspection or is there a real fix?

Sajeev answers:

Much like LSX swaps for people wanting to make a slow car fast, much like Panther Love for someone wanting a cheap and durable ride, I pretty much always think Dex-Cool is the problem when certain vintage GM products have temperature control problems.  As this paragraph shows, Dex-Cool is not my friend…and I am somewhat less goofy than the Car Talk peeps.

On the plus side, others are in your situation and they agree with me. Let’s face it: the timing belt proves that this car was neglected.  It’s a safe bet that Dex-Cool was never changed either, possibly topped off with non Dex-Cool compatible fluid too.  So there is a TON of the stuff you see in the photo below. And above. So I suspect that the 1 week grace period you mentioned was the time necessary to re-clog that temperature sensor and cause the P0128 to trip yet again.

I’d recommend a closer look at your cooling system, probably replacing the radiator too.   Just be careful how aggressively you remove Dex-Cool from the cooling system, you could flush it all out and get a ton of Dex-Cool “snot” stuck in the heater core. Which means you no longer have a heater. Which means…well, have fun removing the interior to get the heater core out. In a Utah winter. Damn, Son…

Sorry, I wish I saw another way out.  Maybe the B&B can help.


Send your queries to Spare no details and ask for a speedy resolution if you’re in a hurry.

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Piston Slap: The Time Value of Automotive Love Mon, 07 Nov 2011 15:01:19 +0000

TTAC Commentator A Caving Ape writes:

I have a 2001 VW Jetta 1.8 with 130,000 miles on it. It has its shortcomings that I can’t fix (front drive, rear legroom), but for the most part it’s a fantastic vehicle for me. But I worry that it’s a time bomb.

I do most of the small/easy maintenance myself, and and happy to pay an independent for stuff I’m not comfortable with (timing belt, front end stuff, clutch when the time comes). This will likely be true with any car I own. I’m very satisfied with the running costs of my car, but from what I can tell I am the only person in the world with a well-functioning early 2000s VW with more than 100,000 miles. This makes me worry that it will crap out on my one day. It’s my only car so this would be very bad.

My question: should I sell it now while there’s nothing wrong with it and I can still get a few grand for it, especially since prices have picked up lately? However that would leave me with (max) 4 grand for a car, plus maybe 3 more I can comfortably part with. But what on earth can I get for $7000 that that I would love as much as my VW, that would also be more reliable? Should I just buy a civic and a motorcycle? Or are all those claims of VWs being crap just a vocal minority, and I’ll be able to keep it going a while longer?

Sajeev Answers

I love those Jettas from a styling and interior perspective, but they are truly crap. Nearly impossible to diagnose MAF sensor issues, bad window regulators, engine sludging (1.8T) even with approved maintenance, and probably a handful of other expensive items found with a second of Google searching. Dig deeper in the forums and I guarantee there’ll be more expenses running up a bar tab that a fully-depreciated Jetta simply cannot pay.

It sucks, because these are truly fun, exciting and beautiful designs. That said, if you devote a large portion of your life to be a 10-year old VW specialist you can make it work. Just be ready for it to consume your life in ways you might never imagine…not that I’d know a damn thing about that. Not one bit.

So I recommend that you sell it, get a Civic and get over the loss of German precision. Or spend much, much more buying a new one with a warranty and enjoy riding the cycle of debt.

Bonus! A Piston Slap Nugget of Wisdom:

Always consider the time value of money in anything you do. For car people, that is aimed squarely at the key(s) in your pocket. Maybe you should do more to spend less in the end, but I suspect that there’s a good reason why so many of us simply must have a new or late model vehicle in their stable. And its not just because we got a great lease deal on a 3-series to impress people.

Send your queries to . Spare no details and ask for a speedy resolution if you’re in a hurry.

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Piston Slap: At Liberty to Go There? You Know… Mon, 29 Mar 2010 15:31:57 +0000

TTAC Commentator cc-rider writes:

Hi Sajeev- I am a huge fan and advocate of TTAC.  I have a co-worker and friend in dire need of some good advice from the best and the brightest. She has a 2002 Jeep Liberty with 110,000 miles.  Last week her car had to be towed to her mechanic.  She found out the engine is toast.

Turns out it is a victim of engine sludge.  After the fact, it seems that this is a fairly common issue with the Jeep 3.7 V-6.  It seems that a new engine would be $3,000 in parts and at least another $2,000 to be installed.

In my opinion, it seems pointless to spend that sort of money on a car that’s maybe worth $4,000.  She doesn’t have a lot of money to spend on another car- maybe $2,000 at most.  She doesn’t put many miles on in a year and goes mostly to and from work.  I am very familiar with the Nissan SR20 engines and am partial to them.  I was recommending she find a used 1st generation Infiniti G20.  They seem to give a huge bang for the buck at that low price point.

I’d love to hear everyone’s take on her situation.  By the way, she is in the NYC metro area for anyone with a cheap ride for sale.

Sajeev Answers:

So she’s just a “co-worker and a friend.” And you’re only “partial” to SR20 mills?  Uh-huh.

I call shenanigans! The first-gen Infiniti G is a wonderful car that’s over 13 years old.  When a dude recommends an ancient ride to a girl that (probably) has no feelings for it, there’s more than meets the eye.  Recommending an old car makes you an instant caregiver: you probably enjoy that person’s company, and they’ll occupy more and more of your time quite soon.

Sorry to bust chops: I won’t recommend my favorite cars to my…uh…friends who happen to be women. And nothing more than that, of course. But if a girlie rolled up in Fox Mustang (Fox anything, for that matter) and wanted my digits, I wouldn’t show her the door. Word is Bond.

Ok, seriously.  The Liberty is a goner because of the reasons you correctly stated.  Unless she really loves the beast: get a used motor from a junkyard (like LKQ or for about $1000, and spend another $1000-ish for labor. It has a warranty, low miles and probably won’t sludge up: if you run a motor flush and religiously change synthetic oil from here on out. There are 3.7L motors that run fine with proper upkeep in brutal urban traffic, I’ve seen that personally.

Otherwise, yes, dump the Liberty and seek alternative transport.  You should help her make that decision, yet narrowing down the field doesn’t mean recommending antique Nissans. Once that’s done, find a clean example of whatever ride she likes and buy her dinner to celebrate her new set of wheels. And if someone finds out they are “partial” to more than SR20 engines after a few sips of vino, so be it!

(Send your queries to

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