They told you it was fixed, they road tested it and said it was running fine, but the engine failed as soon as you picked it up. Do you have documentation of the repair process that says the car was fixed and ready to be released back to the customer?
No heat when you picked the car up says to me that the cooling system was empty. Sounds to me like maybe somebody didn't fill the cooling system properly, which lead to the engine overheating, or maybe they didn't actually drive the car at all to see if it was ok. They should have driven the car enough to get the system to full operating temperature to make sure everything was right. No coolant will cause a serious overheat event leading to failure of the head gasket and/or cause the head to warp.
In any event this is pretty clearly the dealer covering his ass here and denying any responsibility.
Did any warning lights come on?
Call Mazda North American Operations headquarters in Irvine Ca at 1-800-222-5500. MNAO is the Mazda corporate office for the USA and Canada.

 

Yes, I have all the documentation from the original repairs, and I was told the car was fully operational.

I drove it a few times over the next three days after getting it back from the water pump repair. On the first two days, I drove for less than 15 minutes each time and noticed the heating wasn’t working. Since it was -15°C outside, I initially assumed the extreme cold was the reason. On the third day, I took a longer drive and realized the heating still wasn’t working. Concerned that it might be due to low coolant, I called Mazda, and they advised me to bring it in.
It wasn’t until I was driving to Mazda that I got the first and only dashboard warning about the engine overheating.

They admitted that they should've caught the damage done to the engine before the water pump repairs and offered to refund that if I replaced the engine with them. Issue is I believe the damage was done after the "repairs".

I appreciate your reply and will contact Mazda corporate again if negotiations fall through with the dealership. Problem is I already contacted Mazda Canada over email and the representative basically said the car doesn't fall under warranty anymore and its up to the dealership now.

 

This is a tough one. First, I can confirm that the design of the water pump is to leak when the seal is compromised. This is often called a telltale. The leak should be small and is there to tell you to replace the pump. If it's missed and gets worse, yes that is trouble.

I have also had a loss of coolant event with my 3 and it did result in warping of the head/block but it was extremely mild. So much so that I have a tiny external leak between the head and block. It's so sma that I put about an ounce in every 2 or 3 months. Compression is slightly lower in cylinder 1, but still within spec. So I got lucky and don't care to fix it.

We have had another member who lost either the pump or the belt (don't remember which) and the overheating light did not work. Cooked the motor real good and had to get another.

I agree that this sounds like a case of the mechanic screwed up and didn't put coolant in after the job was done.

How's, here's the problem: can you prove that? Does your sensor work?

Corporate is correct in that this does not fall under warranty as it is misuse, weather your fault or not is irrelevant. Therefore the dealer is liable for damages. Now, can you prove it?

If they're not going to pay for this your only recourse is to file a small claims lawsuit. Dealer likely has insurance for this sort of thing so expect to be up against a high priced city lawyer.

Regardless, the burden of proof will be on you to show that this was someone not doing their job correctly. You must prove beyond any reasonable doubt that this is their fault.

The way our law works in Canada you're actually better to have another shop so the work, pay for it and sue them after the fact.

Wish I had something better for you...for me, this is why I started doing my own maintenance. Can't trust half the idiots out there.

 

What if the Tech did not properly "burp" the system when adding coolant? Seems to me, with a cylinder head that is one overheat event away from cracking in the usual spot, that could have caused the problem.

The trouble is, in fact, knowing that that was the initiating action.

Coolant drops/changes always scare me... See, also, the attached graphic that advocates removing the rad cap (cold) at interval and checking coolant level.

 

Based on the coolant leak and later blown head gasket (oil in the coolant), I'm guessing they misdiagnosed it.

 

I disagree. A failed coolant pump is quite obvious due to the mentioned telltale leak point. The description given to the condition of the pump as found backs this up completely.

The issue at hand here is that our motors are insanely sensitive to overheating.

Consider this, you have an aluminum head AND block. Now there's 2 surfaces that have a high chance of warping during an overheating event compared to the traditional aluminum head and cast iron block. Next, factor in that we have a multi-layer steel head gasket. Insanely tough, but requires some very tight machining tolerances to seal. The flatness spec from Mazda is no more than 0.002" across the entire head and block surface.

And then there's the part that they very clearly state not to machine either if it is out of flatness spec but that's going off on a tangent.

Bottom line is it takes very little overheating to trash one of our motors.

One question for the OP: despite some oil in the coolant, how bad is the motor? Is compression ok? How much oil in the coolant are we talking here?

If it's a tiny bit maybe you got lucky like I did. I had a minor accident several years ago which resulted in coolant loss and overheating. I saw it immediately and pulled over.

I do get a very tiny amount of oil in my coolant. Know that this only happens when the motor is cold. When the coolant system heats up, it has higher pressure than the oil so it would go the other way. The heat also can cause things to expand and that can seal it up.

I've been running for probably around 6 years like this. I do keep an eye on things, but I have no reason to fix this. The oil into the coolant eventually slowed down to near nothing - tiny leaks can seal themselves when coolant dries due to the reside left behind.

Either that or my car is self healing...

 

Push harder all dealerships are the same!

 

An engine with no coolant will not register temperature, thereby never initiating a warning light of gauge movement. Sounds to me that the tech never refilled the system with coolant.

 

Or, https://www.mazda3revolution.com/posts/2579370/

The "no heat" issue is a bit of a tell-tale...

 

Despite all of the comments about the dealers repair being bad and them being responsible, fwiw I reckon there’s a good chance that any damage was done during the initial incident, ie the water pump failing/leaking/pulley separating. This would explain why the heater wasn’t working on the cars return. Because the head gasket had already failed due to the WP issue, air was introduced into the system immediately on start up after the pump replacement which usually first shows in the heater circuit.
Personally I would question the need for a ‘new engine’ unless the original has been really cooked or there’s cracks in the head or block.

 

Despite all of the comments about the dealers repair being bad and them being responsible, fwiw I reckon there’s a good chance that any damage was done during the initial incident, ie the water pump failing/leaking/pulley separating. This would explain why the heater wasn’t working on the cars return. Because the head gasket had already failed due to the WP issue, air was introduced into the system immediately on start up after the pump replacement which usually first shows in the heater circuit.
Personally I would question the need for a ‘new engine’ unless the original has been really cooked or there’s cracks in the head or block.

not having coolant in the system would also explain why there was no heat...no way of knowing if the HG has failed before or after repair or if it has failed at all. just because the water pump was leaking does not mean it overheated by far. as mentioned several times here, they are designed to leak to warn the owner before complete failure.

our motors do not take kindly to overheating. if it was overheated badly, a new motor is likely needed. aluminum head and block plus an insanely tight flatness tolerance of 0.002". they cannot be machined either.

the fact that the OP had visible coolant before the repair and none after is very strong evidence. he's observant enough to see the pump leak, he'd see another.

 

The 2.5 Skyactiv-G head (at least) has an area of the casting adjacent to an Allen head plug... that is extremely thin and cracks at the barest hint of an overheat.

 

Would I assume a that this problem with the Mazda Dealer reached a satisfactory conclusion in your favour.

I just saw the thread looking for owners who have had trouble with their starter motor, ie burning out due to over use with reference to I-Stop.

I don't know if you have the facility in Canada, but in Britain we have an organisation called Citizens Advice Bureau, which advises how you tackle a consumer problem, the phrases to use mentioning the laws governing the problem, even a proforma letter which you add your details, turn the handle then edit the final letter so details are correct but sets the right tone. There is also Trading Standards which gather evidence of sharp practices on companies and your info goes as part of inteligence against them , such when it is becoming a common occurrance they prosecute with the full weight of the law behind them and all the evidence.
The way the letters are written it puts them on notice to toe the line with a customer.
Companies try it on , but you have to give a compelling argument and hold them to reasonable deadlines, and if you threaten them with a court case actually carry it out, but hopefully an ADR service will fight your corner before it goes to court.
But you have to be patient and keep at them until you achieve the outcome you want.

I am going through with one now, still waiting for a 90% aggreed refund which hopefully will be in my bank account this week by BACS , some electronic banking thing.
It will be of interest to all on how you got on , your method and resolution.

As with what most people have said, I would say the mechanic didn't refill the radiator, or sufficiently to allow for any trapped air to disipate or check it after it had cooled down following his alledged test drive.

These are MAZDA TRAINED TECHNICIANS supposedly, it doesn't say much for the training then.
Ticking a few boxes after a training video doesn't warrant being trained , of course there is no QA at garages, where somebody checks the work at stages and at the end and asks , 'Did you refill the system'? 'Did you test drive it and get it up to temperature' ?
Main Dealers any make the world over are always suspect. There are good ones and bad ones.