Retired Engineer

I have a 2020 RDX, noticing its consuming over 1qt by 7k miles. I'm an old dude...Had alot of cars, trucks, tractors, boat engines, etc over the years, used to rebuild engines. Outside of a old Monza i had in the 80's with a Vega engine, leaking valve covers, rings gone, etc..i've NEVER had a engine burn this much. Nissan Truck (Titans), Honda Accords, Lexus, etc just from the past 10 years.

Dealership (incompetent kid) tells me to expect a qt upto 3k miles, nothing to do (no leaks). I escalated to Honda, they just parrot what the dealership tells them, no validation or knowledge.

In research, i see various engines have TSB's regarding this (honda just settled a lawsuit on Acura's 3.7-liter J37 V-6 engine over just this). In addition CR did a great article talking about newer engines, in the design changes to improve gas mileage, they have caused issues resulting in high oil consumption. Some Newer Cars Can Burn Lots of Oil - Consumer Reports

The manual (now) doesn't state miles (wonder why?!) in intervals, its all about the "Maintenance Minder", which seems to be triggered from different inputs, but clearly obfusicating the core issue of high oil consumption.

Would love to hear any others issues and any specifics they may have. I recorded the last change, to show full dipstick and will check each 1k miles to track (of course the dealership didn't even recommend doing that..."we don't see any leaks, just keep adding oil, each 3k miles)) WTF.

Only 34k...Shouldn't matter even if it had 134,000. I could refer all my prior cars, but given this one has the 4 cylinder, turbo, i had an old dodge shadow, 2.5L (LONG STROKE on that 4 cylinder..lol)...changed every 15k...all the way to when i gave it to a family member with 155000 miles on it.

As mentioned, nothing in the manual (i can find) with ANY Reference to miles...just all based on the "Maintenance Minder"...i think because of lawsuits, etc, they have removed any mileage indicator. As to changing weights, thats an old school approach, however later engines use their oil as a coolant, and cars with variable valve timing tend to force oil through some pretty small holes, why higher weights not recommended (cause other issues)...bottom line, the engine i think is crap and i'll most likely get rid of it soon as it will only get worse.

I do have a call into another dealership though but its all such a racket.

Right now, i'm evaluating every 1k miles but good idea on compression test. Turbos as you point out can be 'more' problematic, but that goes back to the 80's and 90's ...s the article points out, they have jacked up designs and yes, i'm aware a different engine, just that new models are more suspect with design issues causing oil burn.

Leaf 68

How many miles on your 2020 RDX?

Leaf 68

30k on my 2019 and doesn’t use any oil..so far..

russianDude

Something is not right, it should not louse 1qt every 7k miles. Unfortunately, I believe manual allows for certain oil burn per 1000 miles, and if you are in that range, there is not much u can do with Honda. I would switch to 5w-30 in the meantime

Baldeagle

Honda/Acura has used this 2.0T in 100,000s of cars. I’ve not heard of any oil problems. But yours may sadly be the exception. Have you considered a cylinder compression check to identify a potentially “stuck” ring? That cost will be on you, but may be well worth it. If your cylinders’ compression is equal and normal, this may just be a symptom of turbos in general.

Turbo boost → blow by→ oil vapor pushed out of your PCV system→ oil burnt → oil level decrease.

With a turbo, you need not “drive hard” to generate high levels of boost. With a turbo, you can reach near full-boost at low-rpm and 60% throttle. I feel your pain. Technological advancements (turbos for better fuel economy), are not always a good thing. Incidentally, whatever may be happening to your 2.0T is probably unrelated to the V6 lawsuit problems of past Honda engines. If I recall, the cause of those V6s’ oil loss was their cylinder deactivation. 2.0Ts don’t use that.

russianDude

You need to take a look at some UOA posted on this forum that show significant oil dilution in these engines that causes significant viscosity drops. Your Xw-30 oil will look like Xw-20 in few thousand miles.
as far as tinny oil channels for lower viscosities, this is total nonsense. The same engine model was used in civic type R in UK, and its manual says that 5w-30 can be used. Also, 0w-20 is recommended and not required viscosity. If it was required, you would see different language in your manual. For example, ATF 2.0 fluid is marked as required/specified.
0w-20 is to meet CAFE standards

Baldeagle

I have to support RussianDude that excess concern over thin-oil is unwarranted. If thick oil were a problem, all engines would implode at start up. 20-weight oil is around 8.5 cSt at 212°F, 30-weight oil is around 10.5-12.0 cSt at 212°F. However, 0-weight oil is around 400+ cSt at 25°F. If our engines can handle “honey” in the morning, they will have no problem with 30-weight or even 40-weight at full operating temps. If this oil burn concerns you, I would not dismiss 0W-30 oil.

Retired Engineer

I agree..shouldn't burn this amt of oil regardless of weight. Piston Rings, crankshaft seals, etc are suspect.

russianDude

There are reports of people observing reduction in burn rate by simply switching oil brand and/or viscosity. Would not surprise me if Acura says 1/7 qt burn is normal for 1000 miles. But we all know its not, because no one else has this issue

NooYawkuh

So, what do you want or what would you do? Rebuild / overhaul the engine because you're down a WHOLE quart between oil changes?

Let's see , ... $4,000-$5,000 for a reconditioned engine to avoid a $10 quart of oil once or twice a year.

No dealer will do that and no reputable mechanic would recommend that, no matter how much more money than sense you may have.

The engine is not "burning" oil. It's "using" oil. All engines do.

russianDude

what he has is not normal, most of us do not louse 1qt, but I am fairly certain Acura will say his oil burn is within the expected. They will not replace the engine, unless they see a leak or something.

Retired Engineer

Noo Yawkuh post was idiotic, not worth even responding to.
Other dealership indicates a problem as shouldn't BURN (not losing as no leaks) a qt within 7k miles as any adult who has owned more than one car would know.
I'll see what they will do about it. Its still fully underwarranty and i'll probably sell it. My wifes car..i'll get her another lexus...her last one went 125k miles, negligible BURN (<1/4 qt) inbetween changes (as my truck, prior sedans, etc).

russianDude

My 2012 lexus owner manual says that max allowed oil consumption is under 1.1qt per 600 miles.
the manual also says: the amount of oil consumed depends on viscosity and quality of oil. It also says that new engine consumes more oil. Acura does not say any of that. However, my lexus now has 120k miles and does not consume a drop oil in 10k mile OCI. I always found this statement in manual confusing.
1qt per 600 miles is a lot. but for those unlucky ones, dealer
could say its within the allowed norm.

NooYawkuh

Well, you responded despite it not worth responding to.

So. I'll ask again. What do you think the dealer should do to resolve it?

Retired Engineer

I responded to RussianDude who actually provides reasonable input but to answer your specific question:
What the dealer should do: In order, compression test (& any other tests to determine source of burn, valve inspections, etc), then upon a consumption test (yes its a thing), then make a determination of a new engine with any improvements. AGAIN, if you actually read my original post, including consumer reports articles (many more like it), the Honda Lawuit (on the V6), etc etc..this is a PROBLEM, particularly with some newer (Screwed up) engine designs.

Its still under full warranty but for a guy that thinks this is 'normal'...doubt any of this resonates.

Retired Engineer

BTW..it shouldn't be 'what i think' a dealership should do (not everyone is as experienced with vehicles), it should be the RIGHT THING TO DO...The quality of these 'tech's' (some of it i'm sure is management pressure) is embarrassing. I feel sorry for those NOT experienced and think 3k mile BURN of a QT of oil is 'normal'..

Being taken advantage of.

NooYawkuh

Okay. Good luck.

hand-filer

As a former owner of a problematic Gen 2 RDX I can assure you that Acura corporate doesn't give 2 shits about your oil consumption issue. Good luck.

attofarad

They did the right thing. 1 qt in 7k miles is not a problem, even if most cars don't burn half of that. If it were out of warranty, would you do anything about it other than add oil as needed? What if it burned a quart every 2k miles? Would you do anything about it, other than add oil and maybe clean or replace PCV components? If you are concerned about that rate of consumption, I suggest that you consult a qualified independent mechanic who may indeed find a simple fix. I pay for medical tests out of pocket which IMO should be covered by insurance because I want an answer, and pay for mechanic stuff out of pocket if I want an answer.

You are pretty funny, thinking that "any adult owning more that one car should know..." My previous car starting burning some oil between 5k mile changes around 80k miles. 100k miles later, it still ran better than new, got better gas mileage than new, and was consuming a lot more oil. You have just been usually lucky with oil consumption on the cars you have owned.

Hey, if you have the common fuel dilution, you may be using even more oil than you think. (maybe we are all burning oil, but your car is lacking the fuel dilution the rest of us have to make up the difference ;-)

russianDude

Its not a bad idea to check compression, but if everything is within the specs, there is almost zero chance they will offer to put a rebuilt engine. As I said earlier, Lexus 2012 manual states that up to 1.1qt per 600miles is normal. But in practice, I get zero burn in 10000 miles. Seems crazy they put this in the manual, but its there for a reason.

There is also a good chance that using quality oil brand with lower NOACK and thicker viscosity will reduce oil burn. I would try those steps first before selling the car.

Retired Engineer

Sales folks must LOVE YOU!!! "my last care starting burning oil in 5k miles"...lol...as i stated in my original post (and backed up by CR link i also listed, you obviously didn't read)...engine design changes have led to this problem....We are back in the 50's-80's of checking oil when getting a gas fill up! Other than a piece of shit Monza i had in the 80's that burnt oil (rings , PVC, etc), then problematic valve cover gaskets with a 350 small block, i've had dozens of cars..NONE burn oil like this....

old dodge shadow, another 4 cylinder 2.5 L ran 155k miles, 'burned' maybe 1/4 a quart inbetween 15k mile changes...etc etc.

Go buy the oil burners..I won't.

Baldeagle

Sometimes a clogged PVC valve can lead to oil consumption. A clogged PVC value can’t relieve pressure in the crankcase. That excess pressure “pushes” oil up past the rings and into the cylinder where it burns. That same oil can also lead to a sticky piston ring(s) and exacerbate the problem. Just something else to check as you hunt for the root cause.

Retired Engineer

Yep, although one would 'think' Acura super techs would have checked...Kind of funny, speaking of the changes over the years...Shaking those valves used to be common back in the day when changing oil/filters but another thing i havn't (had) to check in decades on my autos.... Although after youtubing where this one is..another 'not like the old days'! gotta pull the cover, unscrew a bolt to pull it out! What a pain...speaking of youtube and what ended up being the CA LAwsuit..check this out...
..

attofarad

Looks like you did. Are you going to fix it, get rid of it, or let it be? If "engine design changes have led to this problem" what are you going to do? The author of the CR article was burning oil at 10-12 times the rate you are -- an actual problem. He also didn't bother the check the oil in his new-to-him used car for thousands of miles. I might go a couple of thousand on a car with which I was familiar, but not a new-to-me car. Since you are the kind to have "had dozens of cars," it doesn't seem likely that you would keep your RDX long enough for that low oil consumption become a real problem. If not, keep an eye on it, and enjoy. A compression test, if bad, might provide some info. A good compression check doesn't mean much, since the oil control rings might still be an issue. I think I remember that Kia (?) was found to have improperly annealed a bunch of oil control rings, leading to high oil consumption at relatively low miles (50k?).

Not so sure that salespeople "love me." I had my previous car for 19+ years before buying my replacement, and kept it another 2.5 years after that purchase. Ran great, ate some oil -- likely because synthetic oil was "recommended" (later changed retroactively to "required") and I ran dino oil in a turbo for ~40k miles. Annoying? Only slightly. Concerning -- somewhat, since I didn't really want to have to do something like replace the turbo, but it worked out for me, and is probably working out for the guy that bought my 22 year old car for $2k. All that extra oil I bought raised my cost of ownership by a small fraction of a percent over 22 years of ownership (maybe $12/year). I'm more bothered by the RDX's crappy gas mileage, tendency to have back windshield glass spontanously shatter, and actual fuel dilution than I would be oil consumption at your rate.

Like you, I find it annoying that the MM is the only reference we get, without actual or estimated miles for service intervals. To me, the MM makes some sense for oil changes, since it can essentially count the total number of engine revolutions, number of cold starts, etc. One can certainly go longer (in miles) between oil when the car sees predominately highway miles. It make less sense to align the other services (e.g. rear diff) to occur at the next oil change, even when it would not yet be due on its own. Yeah, the convenience of not having to take it in as often, against the higher maintenance cost. Poster Wander provided this chart from back when dinosaurs still roamed the plains (2005 MDX), which I also use for reference: Miles based maintenance schedule

russianDude

I might sound like broken record, but oil in these cars should be changed every 3-4K miles, 7K miles is way to long. These are heavy oil diluters.

sonyfever

Unless this is your science project, I would advise sell it and move on. Debugging this costs you time and money, and at the end of the day a quarter is a lot, but probably still within tolerance. Maybe the best they will do is offer you free oil changes? Not worth the troubles, unless you want to lawyer up. Which brand of motor oil and gas do you use? Does the engine behave well other than the oil burn?

Retired Engineer

So far the dealership has been doing the changes (so whatever oil they use..i just specify synthetic) as i've found other minor warranty issues they take care of. Other than oil burn, yes, it performs ok. I will sell it and move on, back to Lexus most likely (Wifes car ...i drive a titan).

Retired Engineer

"in these cars"...what do you mean exactly by that? Later engines that the CR article refers to?

my broken record: i've owned 18 auto's over 45 years (me/wife/daughter), working on many esp. in my young days...Since the 1980's i've NEVER had a vehicle with this kinda burn (aforementioned vega POS engine, rings, PVC, etc and a 350 small block i couldn't get the valve covers to stay sealed long)...I've always changed oil at 12-15k miles (synthetic) and at most, down 1/4 qt. at time of change..that includes most recent vehicles of previous wifes Lexus, my previous Titan (sold at 120k miles) and current titan (2019).

russianDude

unfortunately oil dilution is still an issue in 2.0t Honda engines. Various UOA from different people are reporting 5%+ oil dilution and viscosity dropping to equivalent Xw-10.
your previous experience can not be applied to GDI turbo engines, especially if its made by Honda. These engines need thicker oil and shorter OCI. The data is in the actual oil analysis, and not some anecdotal evidence

Retired Engineer

Got it..2.0 POS as was the V-6 with the settled lawsuit. Sounds like wife is getting a new car and it won't be Honda! In my prior cars, we did have a 1995 Honda Accord EX (V-6) that was a great car...Just uncomfortabe seats...Bought it with 15k miles on it, sold it (made $$) 7 years later with over 120k miles, changing oil every 15k.

russianDude

yeah, the fuel dilution situation in Honda DI is much worse than toyota. They certainly dropped the ball. The 1.5 had huge oil dilution to the point of people getting extra qt, so what they did is they mitigated the issue to make it “better”, but its still worse than toyotas.
we might see any changes in next gen 2.0t design.

I like Honda drive better than toyota, but quality of Honda is on the decline

Unobtanium

I tracked my RDX pretty closely. I could not discern oil usage at 5K, or at 10K. That is 2 oil changes (for me).

russianDude

my oil level stayed constant, yet fuel dilution got to 4-5%. Oil level is not a good way to tell if you have fuel dilution… unless its very bad to the point where you can see it on your dipstick.
Anything over 3% is not good

Dereileak

every time I change my 2019 RDX and my wife’s crv 2018 I smell pretty strong fuel in the oil, I guess I’ll be the Guinea pig to see how long the engines last in these things

russianDude

I also have 10 year old Lexus, non GDI, there is noticeable difference in how oil smells. Oil from lexus has zero fuel smell. RDX oil does smell like gas.

DanD.

Did you try to send the sample to the oil lab? Its just $40 and it will tell you all about the oil condition.

I do it once a year for all my cars or if I used different oil brand just to the impact.

russianDude

I did. These engines put a lot of gas in oil.

DanD.

What do you mean? Engine shouldn't put any gas into oil when its new. If it does, it means seals are not good, which means cylinders are not rounded. How is it can be even possible without manufactures defects?
Gas in the oil leads to thinning the oil and damaging the engine. It must be addressed by Acura.

russianDude

We should all write letters to Acura I suppose.

attofarad

GDI engines cause more fuel dilution than port injected engines, even new. Jason explains some of the reasons, pretty clearly.
It does seem that Honda/Acura has more problem with this than some other manufacturers.