Blue Haze

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All car engines burn oil. 

That being the correct term, rather than “use”  – which isn’t.

It’s an inevitability arising from the fact that they are designed to. Lubrication being necessary to keep the pistons from welding themselves to the walls of the engine’s cylinders. If they fit like a dowel in a piece of furniture, you’d end up with what you get when you assemble a piece of furniture using dowels; i.e., something that (hopefully) doesn’t move.

But you need the pistons to be able to move (up and down) within the cylinders, if you want the engine to run. If you want the car to move. So the pistons are just slightly smaller in diameter than the bore of the cylinders. Oil is there to prevent the two from becoming one.

It’s only a very thin – microscopically so – layer of oil and the piston rings take up almost all of the remaining (and very small) gap between the piston’s sides and the cylinder walls. But some oil remains on the walls and some of it is consumed when the spark plug fires the air-fuel mix inside the cylinder. 

Normally, it is very little – as in so little you’d likely never notice it – unless you don’t change your oil more often than once every 10,000 miles – by which time you might notice the level on the dipstick is down a little.

But sometimes, it is a lot more than that. Even when you can’t see it – as in blue smoke  billowing out of the tailpipe, which used to be the way you could tell a car’s engine was burning oil excessively, without keeping track of the level on the dipstick. The reason you don’ see that as much as you used to isn’t so much because modern car engines don’t burn oil. You just don’t see the result as much – because of the scrubbing action of the catalytic converters (plural) all modern cars have.

What happens is the oil that’s being burned by the engine is burned again, by the catalytic converter – which gets really hot in order to do its catalytic converting. A car’s engine has to burn a lot of oil in order for you to be able to see it – via blue smoke billowing out of the tailpipe. But just because you don’t see it happening, don’t think it isn’t happening – assuming you see the level on the dipstick going down and there’s no puddle on the ground. 

And if it is (and there isn’t) it’s bad – and not just because it indicates an excessively oil-burning engine, which is also an engine that is losing compression – which means an engine that is losing power and burning more fuel to not make it. If it is burning oil excessively, it is also silently plugging your car’s very expensive catalytic converters – plural, as even four cylinder-powered cars usually have at least two. If you have a V6 or V8-powered car, you may have four of the things – two of them “close coupled” to the engine, typically integrated with the exhaust manifolds – and two more downstream. The tab to replace all four – if they get plugged up with oil/carbon residue – isn’t inexpensive.

And you’ll have to replace them, eventually – because the engine eventually won’t run at all once those converters get too plugged up. And it won’t run well long before that. Plus, you will probably not pass emissions – if you live in an area where those are required – and that also means not being to drive the car (legally, at any rate) if it fails the test.

That’s why keeping track of how much oil your car burns is important. Especially if it is a new or late-model car and still under warranty. So that if there is an oil burning problem, you don’t end up paying for it. 

But how much is too much?   

Some car companies will insist it is normal for an engine to burn a lot of oil, as much as a quart every 3,000 miles or so. 

It isn’t. 

That kind of oil consumption indicates an engine problem. It could be poor cylinder sealing – too much oil getting past the oil control rings that girdle the pistons. Oil control rings are slightly flexible; i.e., they expand and contract, to allow the piston to move up and down within the cylinder while also sealing the cylinder enough to prevent excessive oil consumption. But sometimes, poor machine work – or low quality parts – or shoddy engineering/manufacturing/assembly – results  in just that.

It could also be the result of something many new car engines are fitted with called direct injection (DI or GDI). This is a form of fuel injection that sprays the gas into the cylinders as a very fine mist under immense pressure – as high as 3,000 psi. Ordinary port fuel injection operates in the area of 35 psi or so. 

That highly pressurized gas – which is a solvent as well as a fuel – can increase oil burning by decreasing lubrication, which leads to more rapid wearing of the pistons rings and cylinder walls, which leads to . . . more oil burning. Which gets worse and worse until you finally begin to see the blue smoke, which is the signal you’ll soon be seeing a big bill. 

DI/GDI also increases the likelihood of carbon building up on the stems/backsides of the intake valves, which are ordinarily kept clean by the solvent action of the gas being sprayed by the fuel injectors, which are usually located just behind them – in a port fuel injection system. But DI (GDI) injectors are threaded into the cylinder walls and spray the gas directly into the cylinders. There is no “solvent effect” to keep the intake valve stems/backsides from crudding up (with carbon residue from combustion, including from combusting oil) and – eventually – they no longer seal completely when closed.

You get more blue smoke – and another big bill (to clean/de-carbonize the intake valves).  

If you own a car equipped with a DI/GDI (the acronyms refer to the same thing, differently marketed) it is especially important to keep track of the oil the engine may be burning – by checking the level – on the dipstick – regularly, so as to be aware of any abnormality. You can also check the plugs. If they are oil-fouled, then your engine is burning oil – even if you can’t see it.

And burning more than a quart every 3,000 miles – or even every 5,000 miles – isn’t normal, no matter what they tell you. If your new (or new enough to still be under warranty) car’s engine does burn that much, document it – with the dealer – so that when that big bill comes, there’s at least a chance they’ll be the ones paying it.

. . .

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  1. The more I look at that picture, I’m pretty sure that is an A6 Avant, albeit the TDI 3.0. It’s a couple/few year newer than mine but it’s still a “C5” like mine. The A6 C5 ran through 2005. There is no other A6 C5 with that rear end except the Avant (aka “wagon”). It’s a newer than more ’02 based on the brake lights and probably a higher level trim.

    I don’t think the offered the A6 C5 Avant TDI in the USA. Maybe they did but I’ve never seen one. It’s the same color as mine “Ming Blue” which is common for those models.

    Even though it’s a 3.0 TDI and not a 3.0 NA gazzuline engine like mine, it’s hugely no surprise that it’s smoking like the bat mobile. Heck, mine doesn’t smoke anywhere near that bad and I have to add a quart of oil every 100 miles or so.

  2. It had long been accepted that if an engine burned a quart of erl in 3000 miles that the engine was worn out and it was time for a rebuild- This was certainly true in the 50’s, 60’s, 70’s and 80’s- mechanics and engineers were agreed… Now burning a quart in 1000 miles is ‘normal”?! What happened to all the technology?

    Everything in this society is falling apart and getting worse….only it now costs exponentially more, and comes with draconian levels of control…..

  3. Eric,

    My 1990 Chevy C1500 burns a little oil upon every ignition. It manifests as a puff of white smoke when you start the truck cold. It seems to lose about 2 quarts every 5,000 miles. I was told there was a reason for this. Something about the 350s made around those years… Can’t remember at this time. Others I’ve asked seem to indicate that this is no big deal and I shouldn’t worry.

    But, is it? Should I do something about this?

    • BaDnOn,
      It’s over 30 years old. Just keep the fluids topped off and run that beast. The 350 tbi engines are so overbuilt for the power they produce you probably can’t kill it unless you go low on coolant or oil. If it really bothers you pull the plugs and valve covers. Change out the valve seals that are rock hard by now and that’ll likely eliminate the startup puff and much of the oil burning.

      • Hey, thanks NotBad. I most certainly keep the fluids at proper levels. Also, I might just check out those valve seals when I have a proper garage.

    • BaDnOn,
      I would say valve stem seals. Can be done with the proper tools without removing the heads.

      • Thanks, William! That seems to second that hypothesis. Luckily, it looks like I can get a set of those for $10! So, that just leaves the labor and a clear weekend or so.

        • BaDnOn,
          Best way I’ve heard to change out valve stem seals without head removal is to remove the valve covers and spark plugs first. This will allow you to easily rotate the engine by hand and see when the valves close for the compression stroke. Snake some synthetic rope into the cylinder (leaving plenty for retrieval) and rotate until the piston stops, squishing the rope up to the bottom of the closed valves. This will allow you to compress the springs and pull the keepers with a magnet to access the seals without the valves dropping. The little spring compressor with two arms and a screw on top are probably your best bet. Oil the seals before installation. Look up how to set the lash on your engine. I believe the pushrods should be able to easily rotate without up and down play when the lifters are on the circular/closed portion of the cam. It’s been about 15 years since I replaced the heads on an OHV engine so take my valve lash advice with a grain of salt.
          Keep that oldie going. They sure don’t make anything like it anymore.

  4. Buy an electric vehicle and you won’t have to check the oil ever again. Until the one day the EV will undoubtedly disappoint you in some way and you’ll junk it, blow it up, then buy an ICE vehicle that is going to be reliable.

    If you want to have fake sounds, have ship sounds, foghorns, engine room noises. Why not just have music playing?

    Blue haze means you go to the engine store on the internet and have a new one shipped to a shop to be installed.

    Overhauled a V-8 in a Chevrolet, your basic 4-door sedan, a Biscayne, 1962 year model, wish I had bought a new engine instead or a good used. I was only 18 at the time, so I could have goofed.

    It did sell, somebody was going to drive it to Alaska. Didn’t know what they were up against, the Alaska Highway can be some rough road out there past Lake Kluane.

    Harvest time, cucumbers, potatoes, cabbage, green beans are at the growth stage where you have to pick them all, becomes a workout after a few hours. Gets you back in shape, can’t be lazy all of the time.

    Really nice Yukon Gold this year, a bumper crop is forecast for this harvest season, record yields for wheat are expected.

    There is severe drought in other states, but is non-existent here.

  5. Having owned two late-model Fords in recent years (2014 Focus, 2020 Fusion), I never experienced oil consumption between oil changes, even during periods of extensive high-speed driving (like several trips to see my “little goil” in “Yew-Tah”, bombing across the desert from the Sacramento area all the way to the Wasatch Front). Of course, although I pay attention to mileage and what the on-board computer considers “remaining oil life” (based on some manner of algorithm from the ECM, rather than sampling of the oil itself), I’ve usually changed oil IAW time, e.g., I don’t let it go longer than six months regardless of mileage. As for what to put in, since both vehicles were under Ford’s powertrain warranty, Motorcraft 5W-20 as spec’d, Motorcraft oil filter. This not out of any particular endorsement for those products (for all I know, the oil is cranked out by Chevron and/or Quaker State’s refineries, the filter made by Allied-Signal, same as Frams or even Wal-Mart), but simply, should the engine blow up, at least in defending a warranty claim, I could say I was using THEIR recommended products.

    Any dealer service department that begs off diagnosing an abnormality with a late-model ride they sell, often with the dismissive phrase, “they all do that”, is a reason to not buy ANY products from that maker. As well as pursue action via one’s state’s and federal “lemon” laws, though I won’t hold my breath they’ll actually render satisfactory recourse.

  6. Good luck getting a warranty fix for oil consumption! Harley claims a quart per 1k miles is “allowable” in the latest engine design, the M8. I’m fortunate my 2018 Harley M8 doesn’t do this, I also was paying attention for the first 500 miles to make sure the rings seated properly. See also Subaru circa 2014 class action lawsuit for excess oil use.

    • So does Toyota. My TC burns about a quart per 1000 miles. Toyota called that “normal.”

      My 72 Chevelle and 98 Ranger didn’t burn a total of a quart in the combined 34 years I owned them.

    • 1qt/1000 for a motorcycle? Hardly Worthitson for sure. Between the low oil capacity of motorcycle engines and Harleys air cooled designs running hot that’s a recipe for disaster. Imagine having your engine lock up on the highway because Americas oldest remaining motorcycle company forgot how to make an engine. Everything new is sh*t.

  7. To me it has always seemed miraculous that engines can run hundreds of thousands of miles with only a thin layer of oil on the cylinder walls, most of which is scraped off by the rings with every stroke. Modern lubricants are truly a marvel.

  8. During the lockdown on April 27, 2020, GM suspended its share repurchase program, on a day when the shares closed at 22.45. GM also suspended its dividend.

    This morning, with GM shares having closed at 38.72 on Thursday, the company announced it will resume ‘opportunistic share purchases’ of up to $5 billion … and resume the dividend.

    Opportunistic? In 2020, GM shunned the opportunity to buy back shares at 22.45; now it’s all-in with the shares up 72%. In plain words: buying high, selling low.

    If the US – hell, the whole world – is tipping into recession, this is an epically bad moment to devote cash to paying shareholders instead of building reserves to survive the coming storm. GM is literally betting the company on continued economic growth.

    But moreover, it is betting the company on EeeVees and batteries, to the tune of billions in capital investment. All the touts in the press release are about muh Hummer EV, muh Cadillac Lyriq EV, muh Silverado EV, muh Ultium cells plants in Ohio, Tennessee and Michigan.

    Though I don’t trade individual companies, if I did, I would sell short Mary Barra’s dying pig of an EeeVee company to busted-flat oblivion.

    • GM has carte blanche to act stupid, they are government motors after all. It’s more hilarious watching the other (former) big two try to keep pace.

      • ‘GM has carte blanche to act stupid’ — Mr Bobo

        Well, it got even more stupid this morning. Tom Barkin, who heads the Federal Reserve of Richmond, just said:

        “The Fed must curb inflation even if this causes a recession,” adding that The Fed “needs to raise rates into restrictive territory.”

        “I’ve convinced myself that not getting inflation under control is inconsistent with a thriving economy.” — ZH

        Never mind that ‘recession’ and ‘thriving economy’ are two different things.

        Point is, young Tom is hoisting the black pirate flag and saying that he’s going to crush the auto market to fight demon inflation. As a side note, this morning Germany’s producer price index rose 37.2% year-on-year — not a typo.

        Are you listening, Mary Barra? A Cat 5 hurricane is headed your way.

    • Hi Jim

      Cadillac’s $300,000 EV Prototype Spotted On Road For First Time

      Ugly, bad name, overpriced, have to remember to plug it in. No thanks

      300 miles range (you can only use 60% of the battery capacity or ruin the battery) so 180 miles range, in very cold weather -50% = 90 mile range, with the heater on even less…lol…then it needs a six hour nap while the driver staggers around a charging station like a drunk hobo.

      from zh comments……really funny

      f,,ckin may as well be 1.6 million in Biden Bux for that yuppie white guilt mobile.

      I mean it will look pretty cool in the near future when its wrapped in razor wire and aluminum paneling so it can make hasty runs through Brazil America favelas.

      4.1 million through the southern border, even the most deluded old white b_tch dem needs to start second guessing what this whole party is going to really look like.

      Detroit is really pushing the limits of (testing) Americans’ stupidity. Given that 40% of the nation is functionally stupid, expect to see a few of these ugly tanks on the road in the near future.

      If you turn the heated seats on the range falls to 75 miles.

      People that drive around in EVs are some of the smuggest people on planet Earth.

      Karenmobile for rich karens.

      Did they hire Edsel’s grandson’s to design that?

      Peak insanity from Joe Dementia union friends…..sucking up for more ESG cash

      Who in God’s name is going to buy this?
      The Mercedes equivalent, the EQS, is faster, has greater range, 10 year warranty and costs less than half. Besides, that’s a freaking electric S Class, not some second tier brand from the 1950s.

      Why not $100k for a Porsche and 200k for gas.

      EVs are nothing but overpriced SUBSIDIZED toys for virtue signaling woke yuppies making over 100k!

      300k for a fancy golf cart no thanks.

      Good, keep making them and bring on the eventual collapse. There’s not enough power in the grid, by a factor of 3, to power an all EV fleet. And they’re not building any more plants to handle charging cars (we’d need about 100 new nukes to power our cars at todays miles).

      We’re moving inexorably to the day when we will be rationing our electricity usage severely and regularly. EVs are the slow moving death blow to our way of life.

      Brandon’s press secretary, “And the battery replacement every five years is only fifty grand!”

      They are going to sell 3. Maybe…….2.3, the 3rd purchaser will refuse delivery upon seeing it in person.

      it maybe expensive and ugly but its true value is in how well it explodes and self drives into parked fire trucks compared to a Tesla…..

      The design reminds me of the American Motors Matador. That was a real winner.

      Let them eat cake” springs to mind. We can’t be far from the collapse at this point. Too bad the post-apocalyptic Mad Max scenario will be tempered somewhat by the barbarians stopping to recharge every 100 miles.

      $300k initial purchase, $20,000 battery pack replacement every 5 years, AND I bet everything is a subscription service, including the windshield wipers.

      Not nicked named Great Mistake for nothing… They took their hard earned heritage and squandered it. After 1979 their cars looked like and drove like they were made by Fisher Price.

      Celestiq sounds like the name of a hooker or **** star.

      It looks like a blue whale. So ugly… over 4000 lb it is…lol

      The CEO of gm is also on the board of directors for the GROOMER company known as Disney..

      Another GREAT WEEK for The DA from Delaware ™!

      Along with demorats and RINOrats, giving people things they do not want and taking away the rest!

      When the company hires based on Diversity, Equity and Inclusion, you get engineers, marketing people and upper management that operate under the WOKE ethos, and as a great man once said, “Everything WOKE turns to $H!T.”

      If I’m driving my loved ones in a machine, I want that machine to have been built by the smartest most qualified people. Not built by people who were hired because of their sex or the color of their skin… that why EV’s catch fire??

      It has to be $300k to cover the cost of lost sales of all the other vehicles Cadillac might have produced. Let’s face it – only the very privilege few will own a vehicle of any sort by 2030

      They work for a short while and then things start to break down but there’s no replacement parts and if there is they’re crazy expensive.

      If you bail out a company you f1ck the free market ideology and that is a problem.

      I saw a $3,000 Cadillac on Craigslist that’s better.

      It will come to a choice between:- 1. Have an EV car parked in the garage 2. Have house insurance…… You can’t have both, once the insurance companies refuse to take on the risk.

  9. Now you are lucky to get a dipstick.

    I found it bizarre the RX8 burned so much oil. When doing changes on my FC RX7 back in the the day the oil would come out looking new.

  10. Back in prehistoric times, before cats, it seemed to me that chevys could drive many miles, maybe thousands, blowing clouds of blue smoke. Chryslers and Fords, not so much. I have no idea why that might be so, or even if it was, or just my faulty perception at the time.
    By the end of the ’90s, cars were so reliable, and so low maintenance, that it was not hard to forget they actually needed maintenance, and forget to check things like oil and water. I’ve been guilty of it at times. Especially when after the 50th time of checking, nothing was needed. Which of course doesn’t make it right, and definitely not smart.

  11. Yeah, I didn’t know it when I originally bought my ’02 A6 Avant at a used car dealership in Philly about 6 years ago that it was one of many Audi models that suffered from excessive oil consumption. Not knowing that, I further didn’t understand why my O2 sensors were complaining. I didn’t see any smoke at all at that time.

    They told me I needed new catalytic converters to the tune of $7,000.

    I also didn’t know that was a misrepresentation at the time either. Because, although true enough — the cats were fouled by the excessive oil consumption — just replacing the cats was clearly not the answer. But I didn’t know that at the time.

    I managed to get a local repair shop to replace the cats with aftermarket cats. And the O2 sensor came back in a few months. As the months went by (and that was my daily driver), the oil light started coming on! I was having to put oil in the car VERY often.

    Nobody that has serviced that car, to this very day, has ever been honest about the situation. Clearly the rings are shot and/or the cylinder walls are worn. It now smokes on startup but doesn’t keep smoking visibly after it warms up.

    It hasn’t been my daily driver for more than 2 years now but I still don’t want to give it up. It is a mid-sized wagon with lots of cargo space. I use it to haul shit around but even with a replaced engine (of the same type), there’s probably no way to ever get the excessive oil consumption fixed.

    After thousands upon thousands spent on that car, it will likely join my previous two ’97 A6 Avants in the local junk yard for about $100.

  12. The primary reason I did not buy a Honda Ridgeline was cylinder deactivation and planned oil consumption. One quart every 1,000 miles is normal? Not to mention “active damping” engine mounts to keep the thing from rattling itself to death. No thank you!

    Since its debut, the J-series’ design hasn’t changed a lot, which has allowed Honda to fine-tune it and work out bugs. VCM variants of this engine, though, are prone to excessive oil consumption. Because the valves on the rear cylinders can close, a vacuum condition develops with the reciprocating effect of the piston still moving up and down. Oil is sucked past the piston rings and enters the combustion chamber to burn once VCM is disengaged. This oil consumption ultimately leads to premature failure of pistons and rings, spark plugs, catalytic converters, and more.

    • RK,
      My primary reason to have no interest in them is that they are NOT a truck. Trucks are built on ladder frames, for good reason. The Ridgeline isn’t. It’s a car with a bed.

    • RK,
      Early ridgelines don’t have VCM. For later models you can buy devices that permanently deactivate VCM. The J series v6 is easily a 300k mile engine, if not a half million mile engine. I have a 2006 ridgeline that doesn’t perceptively use any oil between changes and fouls it very little. Kable is wrong about this truck. It’s body is built around a sturdy frame, not just stamped sheet metal. It’s a good light duty truck similar to Erics 2wd Nissan frontier. They have about the same footprint, capacity, tow rating and MPG. Resale value on gen1 Ridgelines is way up compared to domestic full size pickups that are falling apart by now. The word is out. They’re long lived, comfortable and dependable. They’re not a replacement for a full size truck but the s10, Toyota pickup, Nissan Frontier and old Ford Ranger never hauled 5th wheels either.
      The only disappointment I have with it is the 17/20 fuel economy. If you can get one cheap and you only need a light duty truck snatch one up. They ride like a luxury crossover, have gobs of interior space and are old-school honda reliable.

  13. At first glance, I thought the top image was another photo from the Dodge Charger Daytona EeeVee unveiling, with its Fratzonic Chambered dual ‘exhaust’ smoke machine turned on.

    Pretty sure that ‘Fratzonic’ was coined at a college fraternity keg party. Not so funny, you say? Guess you had to be there to fully appreciate the zany wit …

  14. We always jokingly called it “self-changing oil”. And, my dad taught us to always check oil, tires, etc weekly on cars. He insisted on daily checks for farm tractors and semi trucks.


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