Page 2 of 2 FirstFirst 12
Results 16 to 29 of 29

Thread: 2.5 Turbo - Oil Fuel Dilution Issues?

  1. #16
    Registered Member

    CX-9 GT 2019

    Join Date
    Nov 2018
    Location
    WA
    Posts
    17
    Got an analysis for my 2.5T from oil analyzers... aaaand 5% fuel in 3350 miles.. ouch!

    The oil happened to be a cheap Castrol GTX magnatec. If I understand correctly, it should not affect fuel levels? Better oil should have just maintained the viscosity better.
    Possibly more relevant fact was that I ran only 87 gas this time, as a low interval experiment
    Switching to 91 and AmsoilOE, will check again in 3500.

    At the same time got a report for a q5 with 70+k miles. Only 1.6% over 9500 miles. Most of the mileage was rough due to carbon buildup.
    Attached Images Attached Images
    Last edited by crimeariver; 06-11-2019 at 09:10 PM.

  2. #17
    Registered Member

    CX-9 AWD GT Titanium/Sand

    Join Date
    Feb 2019
    Location
    Northern NJ
    Posts
    22
    oh maan... not again... now I have to check my oil. I really hope our cx-9 is fine.
    I run 87 most of the time. The manual doesn't specifically say you have to run higher, just that it can't be lower than 87.
    Still on original oil, and I don't remember now if I checked the level after picking it up..
    I recently noticed the dealer left my tires overinflated at 54psi, so I wouldn't be surprised if oil was off, too.

  3. #18
    Registered Member yrwei52's Avatar
    Donated: $8

    2016 Mazda CX-5 GT AWD w/Tech

    Join Date
    Mar 2015
    Location
    Plano, Texas, USA
    Posts
    7,714

    Arrow 2.5 Turbo - Oil Fuel Dilution Issues?

    Quote Originally Posted by crimeariver View Post
    Got an analysis for my 2.5T from oil analyzers... aaaand 5% fuel in 3350 miles.. ouch!

    The oil happened to be a cheap Castrol GTX magnatec. If I understand correctly, it should not affect fuel levels? Better oil should have just maintained the viscosity better.
    Possibly more relevant fact was that I ran only 87 gas this time, as a low interval experiment
    Switching to 91 and AmsoilOE, will check again in 3500.

    At the same time got a report for a q5 with 70+k miles. Only 1.6% over 9500 miles. Most of the mileage was rough due to carbon buildup.
    It's the first time to me seeing an oil analysis on a 2.5T with oil dilution issue. On the other hand we did see several reports that when they check the oil level on their 2.5T, the oil level is over the "MAX" mark. It could be caused by over-fill from factory, or the oil dilution? Only time can tell.

    I don't agree Castrol GTX Magnatec is a "cheap" (bad) oil though. It's a full synthetic oil and 5W-30 is the recommended viscosity. It's API SN PLUS/ SN, ILSAC GF-5, and GM dexos1 Gen 2 certified.

    I also don't believe 87-octane gas has anything to do with your oil dilution issue either. We shall see with your next oil analysis which should confirm many things. Please keep us posted.

  4. #19
    Registered Member yrwei52's Avatar
    Donated: $8

    2016 Mazda CX-5 GT AWD w/Tech

    Join Date
    Mar 2015
    Location
    Plano, Texas, USA
    Posts
    7,714

    Arrow 2.5 Turbo - Oil Fuel Dilution Issues?

    Quote Originally Posted by Peregrine7 View Post
    oh maan... not again... now I have to check my oil. I really hope our cx-9 is fine.
    I run 87 most of the time. The manual doesn't specifically say you have to run higher, just that it can't be lower than 87.
    Still on original oil, and I don't remember now if I checked the level after picking it up..
    I recently noticed the dealer left my tires overinflated at 54psi, so I wouldn't be surprised if oil was off, too.
    How many miles on your CX-9?

    There're several reports in CX-5 forum that the oil is over-filled from factory on their 2.5T. And using 87-octane gas should have nothing to do with oil dilution issue. Try to use Top-Tier gas all the time though.

    For SkyActiv-G 2.5T turbo you don't get better performance with 93-octane premium gas unless you rev your engine over 4,000 rpm. For most 2.5T owners using premium gas is a waste of money.

  5. #20
    Registered Member

    17 Mazda 6 GT

    Join Date
    Apr 2017
    Location
    Ontario, Canada
    Posts
    553
    Quote Originally Posted by Peregrine7 View Post
    I recently noticed the dealer left my tires overinflated at 54psi.
    Not this again.
    Tires are overinflated before shipping, to prevent flat spots from developing while on the boat. Most of us on here know that.
    Checking tire pressures is part of the dealer prep checklist that's supposed to be done prior to delivery to the customer.
    If the tires are still overinflated, it means your dealer tech rep was lazy, cutting corners, and didn't do their job during the prep.
    He probably just looked at them, decided they were OK, and put his checkmark next to "tire pressure checked" on the list.
    Stuff like this really ticks me off.

  6. #21
    Registered Member

    Mazda CX-9 Grand Touring 2016

    Join Date
    Sep 2016
    Location
    Washington, the state
    Posts
    449
    The oil happened to be a cheap Castrol GTX magnatec. If I understand correctly, it should not affect fuel levels? Better oil should have just maintained the viscosity better.
    Possibly more relevant fact was that I ran only 87 gas this time, as a low interval experiment
    Switching to 91 and AmsoilOE, will check again in 3500.
    Nothing wrong with the GTX Magnatec.
    Of course it will affect the oil level. If nothing else changes, the volume of liquid in the sump will be 5% greater.
    Better oil has nothing to do with the viscosity of the oil & gasoline mixture. Dilution is dilution.
    91 AKI & Amsoil oil is money spent that is not addressing the problem with this engine. The possible causes of fuel dilution are stated in the report. The cause of the dilution in your engine needs to be found and fixed.

    I think the high tire inflation pressure is to prevent bouncing and possibly loosening the lashings while aboard the ship. A couple of weeks on a ship's deck is no different for flat spotting that two weeks stationary in a dealer's lot.
    Last edited by PTguy; 06-12-2019 at 03:12 PM.

  7. #22
    Registered Member

    CX-9 GT 2019

    Join Date
    Nov 2018
    Location
    WA
    Posts
    17
    I probably misspoke. I don't consider GTX Magnatec bad (i would not buy it if so) and by cheap I did mean one of the cheapest top-brand options in Full-Synthetics. And therefore I did not expect any margin from it if anything is not good. In comparison, there is some consistent evidence on WRX forums that top dollar 5w-30 (Mobil ESP specifically) maintains viscosity better when there is a fuel dilution. I don't have oil dilution issues on my WRX, so I can't confirm.

    Main question now is... How to even approach the problem? The car is on warranty, how to make the dealership to investigate? Does the oil analysis stands as an acceptable reason for a warranty claim? Otherwise the car starts,drives,idles perfectly.

  8. #23
    Registered Member

    2010 CX-9 GT

    Join Date
    Jan 2011
    Location
    Melbourne, FL
    Posts
    200
    Quote Originally Posted by crimeariver View Post
    I probably misspoke. I don't consider GTX Magnatec bad (i would not buy it if so) and by cheap I did mean one of the cheapest top-brand options in Full-Synthetics. And therefore I did not expect any margin from it if anything is not good. In comparison, there is some consistent evidence on WRX forums that top dollar 5w-30 (Mobil ESP specifically) maintains viscosity better when there is a fuel dilution. I don't have oil dilution issues on my WRX, so I can't confirm.

    Main question now is... How to even approach the problem? The car is on warranty, how to make the dealership to investigate? Does the oil analysis stands as an acceptable reason for a warranty claim? Otherwise the car starts,drives,idles perfectly.
    I would at least take the car into the service department and share the results of the UOA with them. At a minimum, it will start a warranty claim/history that you can point back to in case something fails later. I don't know if the dealer will act on one UOA, you might need several to prod them into action.

    The quickest test to do is a compression/leakdown test to see if you actually have blow by. You could also do a fuel injector leak down test to see if an injector is leaking.

    Good luck.

  9. #24
    Registered Member yrwei52's Avatar
    Donated: $8

    2016 Mazda CX-5 GT AWD w/Tech

    Join Date
    Mar 2015
    Location
    Plano, Texas, USA
    Posts
    7,714

    Arrow 2.5 Turbo - Oil Fuel Dilution Issues?

    Quote Originally Posted by crimeariver View Post
    I probably misspoke. I don't consider GTX Magnatec bad (i would not buy it if so) and by cheap I did mean one of the cheapest top-brand options in Full-Synthetics. And therefore I did not expect any margin from it if anything is not good. In comparison, there is some consistent evidence on WRX forums that top dollar 5w-30 (Mobil ESP specifically) maintains viscosity better when there is a fuel dilution. I don't have oil dilution issues on my WRX, so I can't confirm.

    Main question now is... How to even approach the problem? The car is on warranty, how to make the dealership to investigate? Does the oil analysis stands as an acceptable reason for a warranty claim? Otherwise the car starts,drives,idles perfectly.
    IMO you can at lest start to check oil level more often and see if the oil level is rising. Once your next UOA is back and if it till shows too much fuel, you definitekly take 2 UOA reports to your Mazda dealer.

  10. #25
    Registered Member

    cx5 gt +pp 2018

    Join Date
    Dec 2018
    Location
    arizona
    Posts
    218
    We need more UOAs to make any conclusions. Could be the driving stye, could be fuel, could be anything.

    ...And I still believe fuel and oil plays a certain role contrary to popular opinion that it does not matter.

  11. #26
    Registered Member

    CX-9 AWD GT Titanium/Sand

    Join Date
    Feb 2019
    Location
    Northern NJ
    Posts
    22
    Quote Originally Posted by yrwei52 View Post
    How many miles on your CX-9?

    There're several reports in CX-5 forum that the oil is over-filled from factory on their 2.5T. And using 87-octane gas should have nothing to do with oil dilution issue. Try to use Top-Tier gas all the time though.

    For SkyActiv-G 2.5T turbo you don't get better performance with 93-octane premium gas unless you rev your engine over 4,000 rpm. For most 2.5T owners using premium gas is a waste of money.
    About 2k miles now.

    Luckily I don't think I have the oil dilution problem, at least not now.
    Turned the engine on to warm up for few minutes, turned it off and let it stand for 2 min, checked oil level and it was exactly in the middle between low and high. I don't smell gasoline, it's relatively light and has the right consistency.

    The '17 CRV we had I noticed the problem on the first oil change after 3.5K miles. Oil level was about half inch over the max, it was black, think like water and reeked of gasoline smell.

  12. #27
    Registered Member

    CX-9 AWD GT Titanium/Sand

    Join Date
    Feb 2019
    Location
    Northern NJ
    Posts
    22
    Quote Originally Posted by Buzzman12 View Post
    Not this again.
    Tires are overinflated before shipping, to prevent flat spots from developing while on the boat. Most of us on here know that.
    Checking tire pressures is part of the dealer prep checklist that's supposed to be done prior to delivery to the customer.
    If the tires are still overinflated, it means your dealer tech rep was lazy, cutting corners, and didn't do their job during the prep.
    He probably just looked at them, decided they were OK, and put his checkmark next to "tire pressure checked" on the list.
    Stuff like this really ticks me off.
    I know... it pisses me off, too. You don't know how many times I asked the dealer to provide me copy of the prep checklist.. and I never got it. Obviously some prep was done, or stuff wouldn't work, but apparently not the tires... And at that point even if I got a copy, I'm sure it would've been made to look like all was done.

  13. #28
    Registered Member

    CX-9 AWD GT Titanium/Sand

    Join Date
    Feb 2019
    Location
    Northern NJ
    Posts
    22
    Quote Originally Posted by crimeariver View Post

    Main question now is... How to even approach the problem? The car is on warranty, how to make the dealership to investigate? Does the oil analysis stands as an acceptable reason for a warranty claim? Otherwise the car starts,drives,idles perfectly.
    In my experience, service may use any lies to negate your findings. But demand them to acknowledge the problem when it comes up again, and take details records of your visit.

    Main 2 things you should do at this point:
    1) Open claim with Mazda directly. This is the date from which lemon law case will count.
    2) Get a good lemon law attorney. I can give you mine that helped with our CRV, but he's in PA, and you're in WA, so not sure he can help.

  14. #29
    Registered Member

    Mazda CX-9 Grand Touring 2016

    Join Date
    Sep 2016
    Location
    Washington, the state
    Posts
    449
    Yep, open a warranty claim. 5% fuel dilution at 3350 miles is a serious matter. If you wish, make an appointment to sit down with the service manager, not just one of the service writers. Don't tell them how to do their job, but do tell them that you want this serious problem repaired. My initial thought is that they'll just replace the four injectors and send you out the door. That might not be their method at all. Let them decide. You shouldn't have to bear the cost of future oil analyses, but you probably will have to. The analysis doesn't show problem levels of wear metals in the oil sample, so the engine should be fine. The titanium is most likely from the anti wear additive sold by Afton Chemical that is a highly effective and lower cost substitute for the molybdenum compounds that are widely used.

Page 2 of 2 FirstFirst 12

Similar Threads

  1. Oil dilution
    By Hammer68 in forum CX-5 Engine & Transmission
    Replies: 14
    Last Post: 02-18-2019, 03:53 PM
  2. Oil dilution
    By Anchorman in forum CX-5 Engine & Transmission
    Replies: 21
    Last Post: 06-15-2018, 01:58 PM
  3. Battery water and Oil dilution !
    By wlong01 in forum CX-5 Engine & Transmission
    Replies: 15
    Last Post: 05-19-2018, 08:05 PM
  4. Replies: 16
    Last Post: 03-26-2016, 02:57 PM
  5. FUEL IN OIL DILUTION and complaints
    By BROADBEAN9513 in forum CX-5 Engine & Transmission
    Replies: 21
    Last Post: 11-03-2014, 02:15 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •