Car Head Gasket Has Blown 6 Months after Service at Dealer - Does The Dealer Have a Responsibility

LFrowdMan on 10/08/2025 - 19:11
Last edited 11/08/2025 - 13:34 by 1 other user

Hi all, at the start of March my car radiator hose exploded and caused the car to overheat, but it was put into limp mode.

We got the car towed to the dealership to get fixed, while it was there, I asked the dealership to give it a full service and check over to make sure the car would have no issue down the track. They did the check and ensured me there would no issue further down the track.

Now I took the car in for a different issue after 6,000km and five months after the incident. I told them that there was some smoke coming out of the exhaust while I drive it and asked them to do a check over it. They informed me that my head gasket was blown and it's $6k to fix through the dealership.

Now from my light mechanical experience, the only way a head gasket could go is from when the car was to overheat and the alloy engine block has warped. Hence the gasket wouldn't form a good seal between the engine block and head.

I have been very stern with them that they should have picked this up when I asked five months ago and I won't pay the full $6k to fix. But do they have some responsibility as they did ensure that there were no issues over the radiator hose blew.

Do I have any ground to stand on?

Thank you

TLDR: Radiator hose blew in March, car overheated but went into limp mode. Dealership towed it, did repairs and a full check, assured no future issues. Now, 5 months and 6,000km later, car shows smoke from exhaust, diagnosed with a blown head gasket, quoted $6k to fix. I believe the overheating caused engine block warping, leading to gasket failure. I feel the dealership should've caught this earlier and questions their responsibility. Seeking advice on whether there's any ground to dispute the cost.

EDIT; Thank you all for your advice, based on the opinions, I will be scrapping the car,
just wanted to see if there were any other options. First post as well, so thank you for helping.

Poll Options

  • 12
    Argue with Dealer for them to pay
  • 283
    Suck it up and pay
Automotive Car Mazda SUV

Comments

  • foursaken on 11/08/2025 - 10:16

    You don't know what you're talking about. Stop being a Karen.

  • pharkurnell on 11/08/2025 - 10:57

    What exactly does the $6000 quote cover?

    Remove/replace engine?
    Re-machining the head and block?
    Reconditioning of head?

    • pegaxs on 11/08/2025 - 14:00
      +3

      Dealer principles 40' yacht payment…

  • stuffandthat on 11/08/2025 - 11:23
    +1

    Can't wait to see this post referenced in next Monday's Weekly Random Discussion post.

  • gutwagon on 11/08/2025 - 11:46

    The dealer has no responsibility for the damage. Who normally does your servicing ? They could have picked up that the radiator hose was showing signs of age, swelling or cracking and recommended replacements. But sometimes they blow without any warning signs. It's probably just bad luck.
    Shop around for a better price , 6k seems way too high.

  • petestrash on 11/08/2025 - 13:01

    You don't really have much to stand on. If the dealer did find the issue originally you would have still been up to similar costs to fix it.

    It's a ton of money for that sort of job.

    The only thing you can ask for is the compression tests done after the hose failed and the car was towed in for repairs.

    The shop should have checked for other damage before changing the hose knowing there was an overheat event.

    If they never checked for heat damage during the original repair, then they were negligent in the first repair.

    With the correct information you may have chosen not to fix the car initially, or sold it on before it got worse.

    This may be the only course if you are looking for a legal option.

  • Typical16-bitEnjoyer on 11/08/2025 - 13:26
    +2

    Mazda CX 5 Diesel. Surprised it lasted thing long. Go to some dealers and trade it in. You'll find one that won't start the car and check it over.

  • JimB on 11/08/2025 - 14:01

    That's amazing that a 2014 Mazda CX-5 Diesel died so early.

    I expected better from Mazda.

    From what I read on OZB, you'd think all Japanese cars hardly break down and European cars always break down. Other OZB'ers are asking why didn't you buy a Toyota Camry.

    Good luck OP on finding a reliable car!

    • LanceVance on 11/08/2025 - 14:13
      +4

      Mazda diesel's are known to be shit.

      • JimB on 11/08/2025 - 14:20

        OK, I heard they were but you wouldn't expect a 11yo Mazda to be scrapped.

        You'd assume Mazda would have fixed the problem when replacing the engine

        • LanceVance on 11/08/2025 - 14:34
          +2

          I agree, I would expect better from Mazda. They have seemingly taken the option of abandoning diesels altogether.

          • JimB on 11/08/2025 - 14:45
            +1

            @LanceVance: They still sell diesels in Australia-
            - 3.3L straight 6 in the CX60, 70, 80 & 90.
            - 3L four in the BT50.

            The 3.3L straight 6 was only introduced 2 years ago.

            Hopefully Mazda have learned from their mistake.

            • brendanm on 11/08/2025 - 17:52
              +1

              @JimB: The bt50 is an Isuzu engine. No idea about the other one.

          • JIMB0 on 11/08/2025 - 15:54

            @LanceVance: This was from an era before electric cars, where annoying people who thought they knew it all would rave on about how much money they were saving on fuel with their 2 liter direct injected turbo diesel. They were blissfully unaware that it was working many times harder than the old gutless Landcruiser diesels that lasted forever. The fuel savings evaporated the moment the repairs bills came.

            Lots of manufactures rushed product to market to meet demand. Often skipping long term reliability testing in the process.

            Meanwhile anyone with half a brain was enjoying an old reliable, powerful, smooth, petrol car that sounded great and the extra fuel costs paled in comparison to the depreciation on these diesel cars.

            • LanceVance on 13/08/2025 - 08:10

              @JIMB0: @JIMB0 if you're saying that emissions regulations have ruined the diesel engine…… then I have no option but to enthusiastically agree with you. It's a shame because I've always liked the torquey way that TDI's drive.

              • JIMB0 on 13/08/2025 - 08:22

                @LanceVance: The old diesel engines were super reliable. It was making them perform like a petrol engine that changed that.

        • brendanm on 11/08/2025 - 17:51

          Have a look at some of the crap they've put in that engine, they are ridiculous. Twin turbo, low compression, variable valve lift just to get the thing to start, terrible dpf regen strategy (fills sump with diesel) etc.

  • Sharp on 11/08/2025 - 15:11
    +1

    https://www.repco.com.au/oils-fluids/additives/radiator-addi…

    Try a selaer and see if it helps before spending any money on it.

  • Sinnerator on 11/08/2025 - 16:30

    What color was smoke?

    • notaccel on 11/08/2025 - 20:14
      +2

      We've already got a new pope

  • greencomet on 11/08/2025 - 17:20
    +1

    "They did the check and ensured me there would no issue further down the track"

    That's as good as a few years of extra factory warranty that is…

  • Brick Tamland on 11/08/2025 - 21:28

    I am confused. Why is it the dealers fault your head gasket blew? Maybe if they replaced the head gasket at the time which came with some kind of warranty for the works. You can’t just check the head gasket.

  • morebunnings on 12/08/2025 - 00:37

    We got the car towed to the dealership to get fixed, while it was there, I asked the dealership to give it a full service and check over to make sure the car would have no issue down the track. They did the check and ensured me there would no issue further down the track.

    Yeah nah, a service to make sure everything is OK on the day does not constitute a mechanical warranty for 6000km / 5 months.

    Especially with a head gasket. They could only inspect that it didn't have any leaks at the time of service, not how close it was to blowing out / leaking.

  • Retchey on 12/08/2025 - 07:12

    I stopped reading after the first sentence,.
    Dealer has ZERO responsibility.

  • Ozbargainusername123 on 12/08/2025 - 09:41
    +2

    I feel sorry for mechanics having to deal with folk who have no idea.

  • cpapi on 12/08/2025 - 12:51

    LOL. Literally the nightmare customer.

    • CocaKoala on 12/08/2025 - 15:43
      +3

      Mechanic replaced my windscreen washer fluid but two months later all 4 tyres burst after I drove the car over a set of retractable spikes. I think the mechanic is liable.

  • MrFunSocks on 12/08/2025 - 16:05
    +4

    Dealership …… assured no future issues.

    The absolutely did nothing of the sort lol.

  • Gravy on 12/08/2025 - 20:48
    +1

    There's one possibility I can think of where the dealer may be at fault, but not sure if it would occur so long after the service.
    About 20 years back a friend of mine had a fairly recent model Holden Astra (I think it was only about 2 or 3 years old) and took it to either the dealer or regular mechanic to get a service which included a coolant change.
    Trouble is they used a different coloured coolant than what the car usually used (pink or green, cant recall which).
    Within a few days the auto gearbox of the vehicle started having severe issues. Turns out the original coolant wasn't fully flushed/drained (likely still some in the heater core or something). This resulted in a chemical reaction between the two different coolants that created a thick sludge and blocked the cooling system, cooking the auto gearbox in the process.(I could see the sludge in the radiator, and not like your normal oil in radiator sludge),

    You mentioned radiator hose had failed, meaning they would have had to refill the coolant, I guess it is possible that a similar mistake was made, not sure how you would test for that but if there is sludge in the radiator that may be able to be tested. Perhaps it could cause a slow death over 6 months?

    • JIMB0 on 13/08/2025 - 08:16

      Unlikely as the dealer is going to use genuine coolant.

      • Gravy on 14/08/2025 - 10:17

        and yet mistakes happen… even if unlikely. It's also more likely that basic jobs such as fluid changes are delegated to junior mechanics with less experience.

        We also don't know if the "dealership" in question here is a secondhand car yard or genuine dealership for that particular make of car.

  • imnotgoingtopayrrp on 13/08/2025 - 10:02

    Damage was done to the car in the initial overheating. Possibly warping the head. It would cost big bucks to pull apart the engine to machine the head, so you just put it all together and hope for the best. In your case, the worst has happened.

  • zuuutoootuuu on 13/08/2025 - 20:32

    how much warranty came with the replacement motor?

  • AustriaBargain on 13/08/2025 - 21:54

    You can't ever prove they did anything wrong. And now you've rubbed them the wrong way so you probably need a different mechanic anyway, they will never trust or like you again now.

  • walterwhite on 14/08/2025 - 01:45
    +1

    It sucks, but 6 months after a service your car could have done many KM, been flogged, or has just has reached the end.

    Whether it's women or wheels, you will need your wallet

  • Gravy on 14/08/2025 - 10:30

    What colour is the coolant in your radiator or reservoir? Has oil got into the coolant yet?

    Apparently the recommended coolant for that model is FL22 which should be green. If it gets mixed with orange coolant then it may turn black (ie: if they messed up the coolant change on the last service). Might be hard to tell if oil has already entered the coolant system though.

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