Metallurgical Failure?

2006 Acura MDX w/160k miles running like new but cabin heat levels began to fall off. Service at dealer (who also performed all vehicles scheduled service) revealed 2 cracked cast iron cylinders in the motor allowing coolant to leak by and not reach the heater core. Leaking coolant fried two catalytic converters and remedy is a used engine replacement and new converters.

My position is this is premature cylinder failure. Acura rep says they’ll cut a goodwill deal and instead of $6100 will charge $2900. After already spending $450 to NOT fix the problem, I’m thinking $0 sounds like a better fix and believe this to be a casting failure.

At 160k, you got about as good a deal as you’re going to get. I would negotiate the mileage for a warranty on the work done. I would have it looked at elsewhere to verify their diagnosis. Best of luck.

If this was a casting failure, it would have shown up a lot earlier than 160k miles.
160k miles is not premature for any kind of mechanical problem, on any make of car.

I think that you should just chalk this up to bad luck, or the after-effects of overheating, or…

$2,900 sounds like a generous deal to me.

Any car can have hidden problems. Most all of them will be found during the warranty period. That is why there is a warranty. Your warranty is no more. If you want coverage past that you buy insurance (called extended warranty).

 You apparently chose not to buy the extended warranty insurance so they owe you nothing.  They are making a generous offer.  Take it and thank them.  They don't owe you anything.

I agree with the others, at 160k you’re doing well to get their ‘good will’ price. Disappointing? Certainly! But 100% covered by a non-existant warranty? Sorry, not much chance of that.

p.s. - you might post this on an Acura forum, find out if others have had this problem (first time I’ve heard of it).

At 160k miles you’re really not entitled to one dime from anyone and offering you a Good Will deal like that is actually pretty amazing considering the mileage.

Normally cracks, which are extremely rare, surface after some overheating.

I’d like to hear the details behind some of this.
Remedy is a used engine and Good Will deal is what; a new one?
Acura rep is defined as the guy from the regional office and not a dealer representative?
Explain the 450 dollars to NOT fix the problem? What is that all about?

I’m with the others. A dealership giving you a $3200 break on an engine swap when the car is at least 110,000 miles out of warranty is pretty astonishing.

You should post the name of this dealership so that any of us who happen to live in the area and have Acuras can be sure and give them our business.

I’m inclined to agree that unless there was abuse at some point in the engine’s life there would have had to be a casting anomolie to have two cracked cylinders. Such anomo;ies, generally inclusions or occlusions, can take time to manifest themselves into stress fractures.

But you did get 160,000 perfectly good miles from the engine, and I sctually think Acura is being more than fair in covering all but $2900. $0 always is better than $2900, but in this case I think it’s unrealistic to expect.

I assume the $450 was to tear the engine open and do the diagnosis?

You have verified that this failure is possible. what mean is, without first checking ,one, this is a full cast iron block or a aluminum block with liners? Two, it seems oddd that ALL coolant is divertet by these cracks and none is allowed to reach the heater core.

The claim is that and actual clyinder or cylinder liner is cracked allowing coolant that is in a cooling passage to enter the cylinder, then get injected into the exhaust gasses and come in contact with the catalytic converter? This all happens without the car overheating or losing coolant? Myself, I initally do not like the daignosis. Can Acura say they have seen this fault on at least one other vehicle? Again, I am very suspicious about diagnosis, not that they are trying to rip you off but that they are still just guessing.

Can you describe the diagnostic process the was used to reach this conclusion?

In the end, it does sound like a generous offer, if needed though.

Lets see if I’ve got this correct:

I’m going to assume you are the original owner of the car.
You average about 32k miles per year, have owned the car for 5 years now, and had the original power train warranty run out after 70k miles, most likely. Even if you bought the vehicle used, and got it as a certified pre-owned Acura, that would have meant that the powertrain warranty expired at the 100k mile mark.

Exactly how long do you believe that a company should warranty their engines when you own their vehicles? What makes you feel like you are entitled to more than everyone else on the planet?

Take your goodwill offer, and be grateful that they are offering you ANYTHING at all.
And make sure your next vehicle is also an Acura, as they are taking great care of you as a customer.


You are owed nothing.
My experience is worse-- my Mazda engine and two front cats failed at 81k. Out of warranty, cats only 1k out of warranty, Mazda offered not a penny of assistance.
Your position is completely without merit.

I’m in agreement with oldschool and I’d sure like to know what the 450 was for. Intially the thought might be that it’s for an engine teardown but the OP defines this as spending 450 to NOT fix the problem.

What does that mean? Picking a wild guess out of the air, one could theorize that the car was overheating and some repair(s) were performed to cure this problem. This leads to the possibility that any prior overheating was severe in nature, assuming that is the case.

That bit about the coolant not reaching the heater core also sounds odd to me unless the coolant level was extremely low but I would assume this would mean diluted engine oil.

Thanks to everyone for their input/advice. For those with lingering ?? - Yes, I’m the original owner. The initial $450 repair was to replace a seized coolant valve and then the thermostat. The minimal heat flow prior to fix was same if not a bit less post fix. The cylinder leak was suspected as the dealer had seen 2-3 other instances. The Acura rep asked for additional testing which indicated 2 cylinders involved.

I’ve been taking a friendly discussion tact with the service manager who is reconnecting with Acura. Looks like I will move forward with repair since it beats a car payment in the short run and there may be some use left before getting into another vehicle. You’re all right about not being owed anything, it just seemed freaky when the car performed so well.

Thanks again for all the comments!

Thank you for the follow up and for answering our lingering questions. We rarely hear back.

Normally I’d be inclined to ask what specific tests were performed, as this could have been a headgasket problem, but if they’re willing to cover all but $2900 for a new motor and new cat converters the question becomes irrelevant. You’re getting a good deal here. Besides, it’s reasonable to assume that if they’re willing to pick up that much cost that the cause of the problem has been verified beyond doubt.

Sincere best.

I second that the follow up is appreciated. I do feel a bit more comfortable in that Acura says they have seen this failure and result before, this is better than the standard “never heard/seen this before” response.

There’s still a murky area here.
Is that 2900 for a new engine and converters or a used engine and converters?

The Acura rep has apparently not even seen the car and asked for testing which indicates 2 cylinders are involved. This does not mean the engine has been torn apart at all. If the engine has not been torn into then how does anyone know there are cracks in anything?
Maybe it’s a head gasket issue.

It’s stated they’ve seen this several times. Maybe this several times was due to chronic or severe overheating. A stuck thermostat will do an engine in PDQ.

If for the sake of argument that replacement engine and converters are brand new with Acura stepping into this matter then you can also safely figure that you’re actually paying the entire bill because the cost to Acura of a replacement engine and converters is likely less and certainly no more than 2900 dollars. The cost of manufacturing something on an assembly line is amazingly cheap and the big markup always comes between the factory and the dealer.
While Acura and the dealer likely won’t make much on this deal other than PR they’re also not going to lose anything.

Best of luck anyway.

Remember, you now have a newer motor and should look for a service life of another 100K at least. IMO, they did a decent job trying to keep a customer. Heck, brake jobs can run over $1000 this day and age. I agree though, that if it’s a used and not rebuilt or new motor, it’s not that big a deal for them. New. it’s an excellent deal.

Take the $2900 deal/gift…

You are about 100k of out of warranty.

At 160,000 K even in a five year-old Acura I’d try to negotiate the repair down to $1,500 flat cost. Including money already spent.

Otherwise, to pursue the failure in casting, yes, cast iron is subject to cracking. Generally due to impact, definitely not due to heat.