By on June 8, 2018

VW EA888 Engine exploded view, Image: VW

Jonathan writes:


Our 2016 Passat (turbocharged 1.8-liter four-cylinder) appears to be losing coolant at the rate of a quart per year. We are driving the car only 5,500 miles per year in Chicago, so the coolant system isn’t under a whole lot of loan most of the year. I don’t have any spots on the garage floor under the engine, and the dealership checked for leaks and couldn’t find any.

The dealership did say that turbo engines are expected to eat some oil and coolant, and that there is nothing to worry about. Is that really a thing? I am very skeptical, but I know very little about maintaining engines with a turbo.

What say you?

Sajeev answers:

As mentioned previously, many a modern mill is cool with oil consumption. Perhaps tolerances on your turbo’s internal water cooling and oil cooling/lubrication-infused bearings are such that, in theory, the VW EA888 motor and its BorgWarner K03 turbo could burn coolant even at such a young age. But there’s another reason why…

The EA888’s exhaust manifold (that feeds the turbo) is internal to the engine!  More to the point, the engine’s coolant passages snake around the exhaust manifold runners, then spit coolant in (and suck it out) of the turbocharger. Engineering Explained covers this cooling system (starting at 4:20), so we can extrapolate if/how this causes coolant loss.

Can this integrated exhaust manifolding mean coolant is under more heat/pressure to perform? And perhaps does it creep past seals and burn up at those stupidly fast and hot turbocharger bearings?

But I wouldn’t worry about this slow TSI Coolant Burn, because there ain’t much you can do about it. Do whatever maintenance the owner’s manual says (or not). If your Passat consumes a quart of coolant monthly, if the warranty expires, I am sure a rebuilt turbo (built in your specific housing) won’t be too painful on the wallet, since there are standardized guts within that case. And mercifully, that TSI designed case isn’t that unique in VW Land.

What say you, Best and Brightest?

[Image: Volkswagen]

Send your queries to [email protected]m. 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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70 Comments on “Piston Slap: That Slow TSI Coolant Burn?...”

  • avatar

    Oil burning is one thing, but coolant loss on a almost new car being considered within factory spec by the dealer? Yeesh. I’d look the engine over really carefully, a minor coolant leak might not be seen as a wet spot but rather dried up calcified looking deposits. I’ve sung the praises of the 1.8TSI Passat on here as a veritable mile eater and incredible value new or used, but reading stuff like this confirms the reservations I have in the back of my mind about buying a fine piece of “German engineering.”

    • 0 avatar
      Matt Foley

      Exactly. If I was willing to accept the loss of a quart of coolant every 5000 miles, I’d buy a 2000-05 Impala off Craigslist for $2500, not a brand-new Passat with a 60- or 72-month note.

    • 0 avatar

      GTEM is correct – that coolant is going somewhere. If it isnt sitting in the driveway in spots, then there will be calcified deposits around areas where the liquids flow in the engine bay. If there arent calcified deposits, then that coolant is getting burned by the engine and exiting the exhaust. The latter is bad – well, they are all bad in a new car, but the latter is really bad as it could be a problem with engine block porosity or bad gaskets.

      When the car is started, is there steam coming from the exhaust, even in warm weather? That would indicate coolant is making it down into the oil pan and then recirculating into the cylinders upon ignition. Is there a smell of coolant occasionally while driving? That may be a leaky gasket that is allowing coolant to drip onto a hot engine area.

      A quart of coolant over 5000 miles is a problem. Dont let the dealer tell you otherwise. When the dealership “checks for leaks”, they may have just glanced under the car. A cooling system pressure test is the correct way to diagnose this issue. Have an independent mechanic do it and take the results to the dealer.

    • 0 avatar

      I’ve changed water pumps and coolant elbows on these at very low mileage. You can pressurize the system but will not observe a leak until you begin moving stuff to expose the plastic pump.

      My suggestion to the ’16 Passat owner; cut your losses ASAP and trade this POS in. GTEM’s reservations are exactly right, stay away from German engineering.

      • 0 avatar

        I just had the water pump and O rings replaced under warranty, VW has a TSB for the coolant leaks on the EA888. Apparently the O rings failing is a known problem, I’m not sure why they decided to change the water pump as well.
        You may notice a stain around the back of the engine on top of the gearbox (you have to go looking hard back there behind all the hoses), the VW mechanic saw it and knew straight away what it was.

  • avatar

    I still don’t understand how people are okay with measurable oil consumption, let alone coolant. You better believe if I ever got a vehicle with oil consumption brand new off a dealer lot they would be replacing the vehicle or the engine. I couldn’t imagine having an engine that also drinks its own coolant.

    • 0 avatar

      @Hummer: “I still don’t understand how people are okay with measurable oil consumption, let alone coolant. ”

      — While I can’t explain why, I had a ’79 Dodge 318c.i.d. that for whatever reason would ALWAYS blow the top quart of oil. No matter how often you topped it up, it would lose that top quart. Strangely, if you let it get one full quart low, it never lost another drop until the next oil change, after which it would again blow the top quart. This was, from everything I’d been able to discover then and even now, “normal.” Nobody could explain it.

      And it’s not like it was a low-mileage, little-used example such as I describe below; I averaged over 15,000 miles per year on it.

    • 0 avatar
      Steve Biro

      Hummer… you can blame the oil use in new cars on the latest fuel economy standards. They’re responsible not only for the wholesale move by manufacturers to turbocharged, low-displacement engines but also the use of things like low-tension rings – which almost guarantee the use of a quart of oil between auto changes. If you’ve bought a new vehicle in the past couple of years – and going forward – you need to keep an eye on your oil level. Like it or not, welcome to the brave, new world.

      • 0 avatar

        Just don’t say we need lead back in gas, please.

      • 0 avatar

        The low displacement is because of the control over which China and their blessed displacement penalties have over the automakers!

        (All over some unproven, specious argument about something that was around long before himans existed, and will be here long after we’ve blown ourselves up several times over!!)

    • 0 avatar

      My m54 ate a quart every 1200…my CTS with the 3.6, a quart every 2500, my 1.4 turbo VW, 1/2 qt in 10k, and my J engine Acura, 1/2 quart every 7k at my usual interval.

      I have no idea why one motor eats oil and another does not. They all get the same abuse.

      Coolant goes somewhere, though. I have a pinhole leak in the CTS (Genuine GM Parts FTW and why no mas GM) and I top off the coolant tank at oil changes.

      • 0 avatar


        On four Hondas since 1994, all bought new, except for about a half a quart of oil lost from the initial factory fill due to the ring seating on the variable-displacement cylinders of my latest (and unfortunately last, barring sanity on the part of Honda in the future:-( ) V6, the oil level has always stayed at the full mark between oil changes!

        So any loss of oil over a change interval would be a major red flag! Much less coolant! (Right now, I’m watching and waiting to see how Honda handles the problem of fuel contamination of the crankcase on the 1.5Ts in the CR-Vs! From what I see so far, it ain’t good!)

    • 0 avatar

      That sounds like a personal problem and unrealistic expectations, but hey… I’m not your car dealer so I don’t have to care?

    • 0 avatar

      I bought a 1964 Jaguar E Type that had sat for 20 years and at first it got about 400 miles/gallon of oil. Eventually I found the PO had “rebuilt” the engine and put standard sized rings on pistons that were 0.030″ oversize, but it never used coolant!

      For some reason, the oil use was cured when I put proper rings on the pistons :)

  • avatar

    One possibility may be directly involved with the low annual mileage. This suggests that trips are infrequent and short, never truly allowing the engine to warm up to temperature and properly seat the seals. While not turbo-specific, I’ve seen this in multiple cars and my most reliable ones have all had 300+ mile trips on them inside of the first 5000 miles and most of them at least started such trips within the first 1000 miles. My current second vehicle, a ’97 Ranger, didn’t see that kind of operation from its first owner, which resulted in a hydraulic leak in the clutch mechanism requiring the replacement of boots, seals and other hydraulic components before I could even drive it home. In 18 years, it had only traveled 19,700 miles. After that, it’s first run was over 750 miles and no issues. It took two years and a lot of freeway miles to finally loosen the engine up to factory-rated performance. (Still trying to encourage a few more horses out of it.)

    • 0 avatar

      My usual break-in procedure on a new car is to treat it gently, but normally, for the period specified in the OM.

      But every so often on the freeway, let the speed drop to around 45mph if traffic allows, then punch it to about 3/4-throttle, and hold until maybe 500 rpms below redline, in order to seat the rings.

      As stated above, I’ve done that on all four of my Hondas, all purchased new, and aside from the first OCI on my 2013, which I attributed to the break-in of the variable-displacement system, my Hondas have not used a drop of oil between changes.

      (IIRC, I found that procedure in a book by a Robert Sikorsky, entitled “Drive It Forever.” It’s worked!)

  • avatar

    Would watch out for downstream effects on O2 sensor, cat.

    And, does the coolant directly contact the bearing like the oil does? Or just the surrounding casting? Not sure.

  • avatar

    Water cooled turbos may consume coolant but I wouldn’t consider it normal.

    Turbos are violent pieces of equipment…. elevated oil and coolant consumption is expected when compared to NA.

    • 0 avatar

      It’s a known issue – oil consumption – with the turbocharged N14 engines in MINI. Of course that entire engine is a bit of a fiasco. Most of the problems were supposedly fixed with the later N18 but I still don’t have much faith with most turbocharged engines. Though my ol’ Volvo turbo 850GLT didn’t consume any oil that I could ever determine.

    • 0 avatar

      NO way for coolant going thru a turbo to ingest and burn coolant. It could be a line that goes to the turbo or an overflow pushing it out while driving.

  • avatar

    I still think it is problem that modern engines are “expected” to consume oil (and coolant too I guess). Your one quart down, becomes two quarts down, becomes major mechanical failure.

    We’re probably 5-7 years away from the worst offenders suffering a rash of bearing, timing chain, and HG problems.

    *Piston Slap Bonus* – GM’s new 2.7T uses a similar design to this VW engine, has even more whiz-bang fuel saving technology stacked on top of it, and is being used in applications where it might have to tow things.

    • 0 avatar

      Why is it a problem?

      I mean, “expected to consume some oil” is NOT NEW, after all.

      (My OM617 in my 300D was “expected” to consume, IIRC, up to a quart per thousand miles.

      It was never that bad for me, but it did always eat oil, both from blow-by and from a few very slow leaks [30+ year old diesel with god knows how many miles, after all].

      Such was the universal experience of literally everyone who ever drove an OM616 or OM617, as far as I know.

      And those things regularly last beyond the life of the car they’re in, which is saying something…

      Which makes me a lot less sanguine about “eats oil means will fail horribly”, because why would those two even be necessarily connected?)

      • 0 avatar

        “Why is it a problem?”

        Not having enough oil in your engine causes damage.

        I’m guessing someone driving an old Mercedes diesel is much more meticulous about monitoring oil levels compared to a grandma in a GMC Terrain. If Grandma is perpetually low on oil that will be bad.

  • avatar

    “Problem”: uses 1 quart coolant per year.
    Solution: add 1 pint coolant every six months.

    • 0 avatar
      SCE to AUX

      Agreed. While I’d normally be bonkers about fluid consumption in a 2-year-old car, this isn’t a bad problem.

    • 0 avatar

      Yeah, this is the most realistic solution, especially if you don’t want to battle with a dealership service center about it.

      Besides, if you’re only driving 5k a year, who cares. You’re not stressing the hell out of the car on a daily basis.

      Keep an eye on it, top it off and make the concern known to your dealer.

  • avatar

    Most cars I’ve owned required a little coolant every so often. Not quite a whole quart per year, but as long as there’s no evidence of oil contamination I wouldn’t sweat it.

  • avatar

    I with gtem. A drop of coolant once a minute or so, while driving not when motor is stopped, can add up to a noticeable amount.
    I have seen leaks that either go right down to the pavement or onto part of the exhaust and leave no visible traces.
    Areas to check: Where hoses are connected, Gaskets that seal coolant including water pump and cylinder head, Water pump shaft seal, and system pressure cap. Cap needs to be tested for pressure and its seal carefully examined. Also check where the cap attaches usually on a plastic bottle. Those coolant bottle/tanks sometimes get very small cracks in them that will only open when things are at operating temp and let a small amount of coolant out. Again hard to detect.
    I have seen cars where the system pressure tester had to be left on over night to find a leak.
    And there could be head gasket problems or even cracks (or porosity) in the cylinder head or block. Here again, a small amount of coolant will add up over time and might not give the telltale exhaust smoke if it is getting into the combustion chambers.
    As in the OP the turbocharger housing could be cracked or have porosity. All the liquid cooled turbos that I have seen have the coolant circulating around the bearing housing and not in direct contact with the bearings. Oil goes through the bearings to lube and cool them.

    • 0 avatar

      pwrwrench has some good ideas.

      I had similar problem with a mustang for years. Lost coolant with no tell tale signs. Even a (quick) pressure test showed nothing. Later when the water pump started leaking i broke off a bolt and screwed up the block extracting it. When removing the engine I found a expansion plug completely blocked off from view by an accessory bracket.

      An overnight leak test may have caused enough coolant to leak out to fill up this ‘pocket’ and spill out where I could tell where it is coming from.

      The small amount missing sounded similar to this situation.

  • avatar

    My well used and abused ’05 P71 has used exactly *zero* coolant in the 50k miles since I bought it and it currently sits at 162k miles. Screw VW, that is anything BUT normal. I’d rather walk than drive that overrated junk.

    • 0 avatar
      R Henry

      Those 4.6 modulars are pretty stout, aren’t they? A good number have gone a million miles in commercial use…and keeping their fluids is one reason why.

  • avatar

    That’s *20,000* miles per gallon of coolant. I could not even begin to get excited about that level of consumption. Probably a leak so slow the coolant just evaporates, never making it to the ground.

    Top the thing off at the annual oil service and call it a day.

    • 0 avatar

      Such is the mentality of German car owners :p

      “It’s SUPPOSED to do that! The ethereal German engineers/dealers told me so!”

      • 0 avatar

        well, we can’t all get into clapped out Maximas, gtem :)

        • 0 avatar

          To its credit that used and abused Maxima didn’t burn or use any coolant with 142k on the clock. Neither does my 4Runner with 148k even in the summer climbing some hills and such, neither did my ’96 ES300 with 209k miles on the clock. Likewise I don’t think either of my Lima powered Rangers use any oil or coolant (haven’t owned the ’94 long enough to really tell). Sometimes it seems like the Germans in their pursuit of the latest tech royally screw up the most basic of details.

        • 0 avatar

          My clapped out 162k mile P71 has never used a drop of coolant.

        • 0 avatar

          Nick if you wanted to give me a good jab about the Maxima its that by 142k miles and 16 years the body was rotted enough to consider it for the junkyard. That’s definitely an area the Euros beat the pants off of most everybody!

          • 0 avatar

            gtem it was all with a light heart. but the point is, there is a price to pay for not wanting to drive a maxima or camry and ESPECIALLY a crown vic, and there is a considerable amount of people willing to pay it. not all are lemmings.

            don’t forget…khordes has fared pretty damn well in the department of reliability. the man has some pretty firm ground to stand on.

            and for what it’s worth, i ran an audi from 80 to 140k with no coolant or oil issues. [correction – low coolant warning when water pump started seeping, but at that mileage, not a problem]. I had all the belts and tensioners changed/tightened up before selling it shortly thereafter to a truck driver who wanted it to get to work after totalling his TDI. here’s to hoping someone else after me didn’t regret his next german car.

          • 0 avatar

            It’s all good, I got that it was good natured ribbing.

            “not all are lemmings.”

            Lemmings or people that just don’t have the bandwidth or inclination to suffer the consequences of Germanic over-design (or under-designing things like plastic parts for our temperature extremes and weak suspension components for our roads)? I look at older German stuff (mid 90s) as being pretty long lived, if occasionally finicky. It’s the newer stuff like Audi’s 3.0T motors that are the definition of throw-away cars in my opinion.
            These are in Russian unfortunately, but the guy basically tears apart an older cast iron V6 12V audi motor and comments on its internals and design features that lead to their excellent durability and performance characteristics (for that time), then followed by a tear down of a 3.0 TFSI motor that failed catastrophically at low mileage. Just how flimsy and impossible things like the timing chain covers are to take off, the horrible casting on the engine block:

            Old AAH 2.8L:

      • 0 avatar

        Not to mention that Krhodes1 defended the fact that the entire cooling system in BMWs is a regular wear item.

        • 0 avatar

          ‘Gotta love those plastic tubes underneath the intake manifold on a bmw six cyl. The electric fans go south about the same time as the cooling system.

    • 0 avatar

      “Probably” is not good enough for a new engine under warranty that may have head gasket or engine block problems. Even if it is an external leak, it should be repaired on something this new.

      All of the coolant seals are static except those of the water pump. They should not leak at all.

      If it’s an external leak, UV dye should help you find it. If nothing shows up with that, get an oil analysis.

  • avatar

    IMHO consumption of this magnitude is not normal. Go back and insist on a pressure test, which the warranty should cover. My wife’s 2016 Porsche was giving us low coolant messages, and the dealer claimed to not find a leak. I was freaked, thinking it must be the head gasket or something serious. After multiple pressure tests, they found not one but two very minor leaks at the recovery tank and some other connection. We never saw any drips, no residue, etc. from these.

    The only car I can recall having to add coolant to at all is my 210,000 mile 2007 S550. At that age and miles, who cares that I have to top it off every year or so. I never see any leaks or residue on it either, so maybe the head gasket has a bad place. The oil looks fine (not milky or foamy) so who knows.

    Even the S550 burns no oil, though. The Porsche oil level drops between changes but never gets to the add level (it’s a readout, not a dipstick).

  • avatar

    After parking in my garage, I have noticed coolant odor from 3 separate VAG products: 2012 Jetta TDI, 2016 Audi A3, and the 2016 Golf R. We never see a puddle, never noticed low coolant level. But if the engine has been run for more than 30 mins, the odor is present.

  • avatar

    Chicago car with coolant leak and no external drip? Check the heater core and hose connections.

    • 0 avatar

      gasser & JReed, Thanks for reminding me. VW has had more than their share of heater leaks going back a long time.
      That’s another area to check.
      The old Rabbits were easy to change in less than an hour.
      After they became Golfs in 1985 it was like most current cars; Take out the entire dash.
      Some techs figured out ways to get the heater unit out of the airbox in the dash with minimal disassembly. Sometimes this worked out okay. Sometimes not.
      If the heater is the leak it definitely needs to get fixed under warranty.
      I recall some of the early Saturns got a batch of bad antifreeze which turned into something like rubber cement. Owners got new cars and effected ones got crushed. Too many parts to change including engine.

  • avatar

    So approximately 0.0002 quart per mile?

    Still worrying. Keep until the warranty expires and drop it like it’s hot.

  • avatar

    14K miles and a little over a year on my Elantra Sport with the same water-cooled Borg Warner turbo and the coolant is full, no oil consumption either.

    Probably just jinxed myself though, engine will grenade from Hyundai metal shavings tomorrow.

  • avatar

    I’d consider an oil analysis to see if it’s going into the crankcase.

  • avatar

    I had the exact same problem with the same engine in my Sportwagen. They told me they could not find the leak on two separate occasions. After the second pressure test, I told them the coolant had to be going somewhere, and I would not accept that answer. After discussing it with VW USA, they replaced the heater core in warranty. It seems to have solved the issue.

  • avatar

    I drive a 2015 Golf R which uses a rather more highly stressed version of this engine. Mine also consumes some coolant, although not nearly as much as the OP reports. I keep a condiment squeeze bottle with premixed VW coolant in our garage for periodic top-ups.

    At least in the Golf R community coolant consumption isn’t uncommon. Some cases are explained by leaking water pumps or cracked thermostat housings, both requiring replacement. Others, like mine, have no observable cause — so far. No puddles, no dried deposits.

    With 5-7K annual miles I top mine up 2-3 times a year, maybe 150 ml each.

  • avatar

    Johnathan, trying to chase down a potential small leak or weep in the system can consume a lot of time and expense, often with no conclusive result.

    Do yourself a favour and add some fluorescent tracing dye to the next batch of coolant you add. Drive the car as usual and use a black light in a dark garage to see where it’s coming from. Given your rate of consumption, you shouldn’t have to drive more than a few hundred miles to get a result. If this does not show where the leak is coming from in vidid colour, your car is somehow burning the coolant instead.

    *Just make sure to use the appropriate dye for the type of coolant in your Passat.

  • avatar

    I have 52,000 miles on my 2016 sportwagen. It does not use any oil or coolant between 10,000 mile oil changes. My daughter has a 2008 Rabbit with 175,000 miles. Same thing no loss of fluids.

  • avatar

    Last year, I had a severe coolant leak on my old Legend that never made it to the pavement. I was very worried that the head gasket had failed despite my best efforts. But fortunately it turned out to be a crack in the radiator that I couldn’t easily see, and when the old radiator was pulled out there was a massive formation of deposits on it.

    Oil burns… whatever. It might stress the cats a bit more, but shouldn’t cause any other problems.

    But coolant disappearing… if you can’t find a leak, there’s a real problem.

  • avatar

    I’m having a similar issue with the 2.0 EcoBoost in a 2013 Fusion. It’s a little over 35k miles and driving about 500 miles a month, it has a case of disappearing coolant. I also get a slight antifreeze odor when I park it, which makes me think it might be a bad cap? I can’t find a leak anywhere and although I have Ford Premium Protection, I’m loath to spend $100 to take it to a dealer for them to say they can’t find anything wrong. So I guess I’ll just keep filling it up periodically.

    A Fusion, or even a Passat, to me are throwaway cars. Drive them and maintain them within reason, then get rid of them at the end of their usable life like an old iPhone. I’m not worried about making everything perfect as if it were my baby. I reckon it’s got another 5 or 6 years and then I’ll get something I like better (the fiancee is driving it now, so I guess it’ll likely be a joint decision).

  • avatar

    I don’t have to read past the words “2016 Passat” to give my verdict: Get rid of this piece of junk temperamental money pit while you still can !

  • avatar

    These stories are scaring me. I change the oil on my Toyotas and Hondas as recommended, and I never ever check the oil level. Never.

    After reading this story about newer vehicles using oil, I decided I better start checking my oil. I went out and was unable to get the dip stick out of my Honda Pilot. It is stuck. Could this be because I never pulled it out? Perhaps the dealer never pulls it out after doing and oil change?

  • avatar

    And, a second comment. I really like the looks of the VW Atlas. Then, I read this. The Atlas I am looking at does not have a turbo, but this VW story is causing me to think harder about the Atlas. Would you buy a non-Turbo VW Atlas V6?

    I was a reliable Honda Pilot buyer until the newest iteration came out … talk about ugly. So, I am looking at the VW.

    • 0 avatar

      Vehicles such as the Honda Pilot (whale), VW FAtlas and the like are getting supersized to the point where said manufacturers should at least offer the optional Exxon Tanker Truck escort.

      The Chevy Bluburban, Ford (Mt. Everest) Expedition, Cadillac Escalating Mass and the like are now considered Nimitz-class ships.

  • avatar

    Both Chevy Vegas and some Jaguar E-types perpetually lost coolant due to a too-small OEM overflow reservoir. It would overflow a tiny amount after a hot shutdown somewhere far from home, and owners often wouldn’t notice the wet spot. I’d suggest checking your overflow bottle and hoses for cracks, pinholes for a “mystery leak” like yours and note if the level goes all the way to the top after a good heat soak after a hard run.

  • avatar

    My 2017 Golf 1.8 didnt use any oil or coolant in the same amount of miles from new. It did say in the owners manual that “driven in a certain manner, some oil use is expected” and gave a figure that escapes me now.

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