Page 1 of 8 123 ... LastLast
Results 1 to 10 of 72

Thread: Mirage 3A92 Engine repair in process. (Problem: low compression)

  1. #1
    Junior Member
    Join Date
    Apr 2021
    Location
    Quebec
    Country
    Canada
    Posts
    18
    Thanks
    0
    Thanked 24 Times in 8 Posts

    Mirage 3A92 Engine repair in process. (Problem: low compression)

    Hi, early in marsh I took my wife's 2018 Mirage (55000km) to the dealership because of an engine noise that would not go away after the engine had warmed up. They charged me 400$ to do a compression test and tell me that Mitsubishi would not repair it on warranty because the oil change had some time been done 2000 km to late....

    After some phone call leading to dead-end, I decided to repair the engine myself as the dealership would charge 3000+$ and I estimated the repair to 400$

    Now the engine is out of the car and opened up. The 3 piston have damage to the skirt on one side and the wrist pin are not turning freely in the piston. The cylinder wall have the same kind of damage as the piston.

    I would not find any oversized piston for the 3a92 so I ordered a piston set from rockauto for a toyota 1nz. Same bore, same pin, similar valve relief, the compression distance is a little longer. That I will adjust when the block come back from the machinist.

    The crankshaft look like new, all the bearing have minimal to no wear at all.

    The machinist said that by the look off the piston, the damage would be due to overheating or to excess gasoline.

    The engine would flood 3-4 time during the winter and we would have to start it with full throttle. It would smoke black and smell like snowmobile and then run fine. We have never experience overheating with the car.

    Maybe the engine would run lean and overheat the piston after the over-fueling event like the 2014-2015 were doing...

    I will post picture of everything soon, do you guys have pics request or dimension you would like to have before I put it back together?

    Sorry for my English, I live in Quebec, Canada and do not type in English normally.


    Last edited by MetroMPG; 04-26-2021 at 05:19 PM. Reason: (added info to title)

  2. The Following 6 Users Say Thank You to Dave For This Useful Post:

    AtomicPunk (04-11-2021),CROSSBOLT (11-03-2021),dragon2knight (04-12-2021),Fummins (04-03-2021),ThunderG (04-12-2021),Top_Fuel (04-03-2021)

  3. #2
    Junior Member
    Join Date
    Apr 2021
    Location
    Quebec
    Country
    Canada
    Posts
    18
    Thanks
    0
    Thanked 24 Times in 8 Posts
    Name:  WP_20210403_14_15_49_Pro.jpg
Views: 2111
Size:  97.2 KBName:  WP_20210403_14_16_03_Pro.jpg
Views: 1974
Size:  96.5 KB

  4. The Following 3 Users Say Thank You to Dave For This Useful Post:

    AtomicPunk (04-11-2021),ThunderG (04-12-2021),Wil B (04-11-2021)

  5. #3
    Junior Member
    Join Date
    Apr 2021
    Location
    Quebec
    Country
    Canada
    Posts
    18
    Thanks
    0
    Thanked 24 Times in 8 Posts
    The sound was similar but not as loud. It was getting louder quickly so I towed it from the dealership to my friend's garage. The idle started to get rough when we drove it inside.

  6. #4
    Junior Member
    Join Date
    Apr 2021
    Location
    Quebec
    Country
    Canada
    Posts
    18
    Thanks
    0
    Thanked 24 Times in 8 Posts
    The connecting rod is 133mm c-c, small end is 18mm bore and 17.8mm wide, big end is 43mm bore and 17.8mm wide, crank pin is 40mm in diameter, rod bearing is 13.5mm wide.

    The main bearing housing are 50mm, crankshaft main are 46mm and the bearing are 16mm wide.

    No hole in the connecting rod for piston oiling, only 2 little groove on the side of the big end.

    I cant find the bearing online but again the bearing have the same dimension then the one on a Toyota 1NZ exept that our bearing dont have locating tab punched in them so there is that.
    Name:  WP_20210403_14_42_18_Pro.jpg
Views: 1997
Size:  103.9 KBName:  WP_20210403_14_42_49_Pro.jpg
Views: 1942
Size:  104.1 KBName:  WP_20210403_14_42_57_Pro.jpg
Views: 2013
Size:  100.5 KB

  7. The Following 4 Users Say Thank You to Dave For This Useful Post:

    DirtGearTv (11-01-2021),Fummins (04-03-2021),ThunderG (04-12-2021),Top_Fuel (04-03-2021)

  8. #5
    Junior Member
    Join Date
    Apr 2021
    Location
    Quebec
    Country
    Canada
    Posts
    18
    Thanks
    0
    Thanked 24 Times in 8 Posts
    The engine from the Toyota echo and yaris. A 1.5 4 cylinder that have much in common with our engine, from the oil pump to the valvetrain everything look similar as if when they designed our engine they started on the basis of the toyota.

    Maybe it have someting to do with the Aisin logo on our timing covert, Aisin being owned 51% by toyota.

    The parts are not a direct fit, adjustment are required for them to work.

  9. #6
    Senior Member Dirk Diggler's Avatar
    Join Date
    Mar 2019
    Location
    looking into the abyss
    Country
    Turkmenistan
    Posts
    5,389
    Thanks
    2,034
    Thanked 1,242 Times in 909 Posts
    Man, lately it seems like an epidemic of engine issues in cold weather climates with these engines?

  10. #7
    Senior Member
    Join Date
    May 2014
    Location
    Country is Europe, state is Germany
    Country
    Germany
    Posts
    1,713
    Thanks
    234
    Thanked 1,158 Times in 670 Posts
    Dave, sorry to hear about that, and thanks for posting pix. Presumably you have the FSM?

    My 2014 has about 100 000km (60 000m) on it and thankfully no such problems at all.

    I wonder if the "Eco-Mod" that further reduces enrichment was beneficial for preventing that sort of thing? It doesn't make it start or run harder, just reduces enrichment during start and warm-up.
    See:
    https://mirageforum.com/forum/showth...ment-when-cold

    Btw, the SMART engines were designed in the joint Daimler/Mitsubishi Kölleda facility as was the engine of our cars and of other European Mitsubishi Colt. There are quite a few similarities in that design, and I would expect a few interchangable parts.
    Meanwhile Kölleda is 100% Daimler-owned, and today they make and design allmost all Mercedes Benz passenger car engines.
    Last edited by foama; 04-05-2021 at 01:08 PM.

  11. #8
    Senior Member klroger's Avatar
    Join Date
    Nov 2018
    Location
    ottawa valley
    Country
    Canada
    Posts
    732
    Thanks
    82
    Thanked 443 Times in 310 Posts
    Hey Dave, just wondering, do you keep your car in a heated garage, or use a block heater to aid in cold starts??? Thanks...
    I didn't know what to do, so I didn't do anything

        __________________________________________

        click to view fuel log View my fuel log 2018 Mirage GT 1.2 automatic: 37.3 mpg (US) ... 15.9 km/L ... 6.3 L/100 km ... 44.8 mpg (Imp)


  12. The Following User Says Thank You to klroger For This Useful Post:

    Fummins (12-23-2023)

  13. #9
    Junior Member
    Join Date
    Apr 2021
    Location
    Quebec
    Country
    Canada
    Posts
    18
    Thanks
    0
    Thanked 24 Times in 8 Posts
    I dont have a heated garage, the car stay outside, unpluged all year long. In winter temperature go to -30 celcius.

  14. #10
    Senior Member Top_Fuel's Avatar
    Join Date
    Feb 2016
    Location
    Ohio
    Country
    United States
    Posts
    3,699
    Thanks
    2,582
    Thanked 2,537 Times in 1,471 Posts
    I was just thinking about this thread the other day when I was looking at Mirage oil analysis reports. Mirages seem to have a certain aluminum content in the oil. I'm not sure it's an alarming amount, but it's there. Maybe related to piston skirt wear?!?


        __________________________________________

        click to view fuel log View my fuel log 2015 Mirage ES 1.2 manual: 52.2 mpg (US) ... 22.2 km/L ... 4.5 L/100 km ... 62.6 mpg (Imp)


Posting Permissions

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