New cylinder head..maybe
 

Hello all, I hope someone can give some wisdom with this. My 2014 Mazda cx5 started to overheat per indications on the message center. I would get the red flashing temp light with a message saying “high coolent temp” then a couple minutes later I could get the message “bring to a stop in a safe location” or something like that. At this point the car would go into “limp mode” and only go 20mph. A couple minute later all warning messages would go away and all is well. Then it would go through the same cycle. Never did the car seem to actually overheat.

I took it to a Mazda dealership and they looked at it and said it was a computer problem and that it needed to be reprogrammed, I found this odd but ok. I drove it home and around no issues. A couple days later heading to work it did this overheating thing again. Same cycle. I took it back to the dealership and they have had the car for days. Today I got word that they said it is a “bad cylinder head” and that due to the milage and the fact that it overheated they should just replace the engine for $7000. I asked if there was any oil in the coolent or coolent in the oil and they said no, that coolent is going right into the cylinders and being burned off, but there is no white smoke or black smoke or any smoke coming from the exhaust.

I find it interesting that the car would go from overheating to not overheating and so on, and I personally don’t think it’s the cylinder head but I don’t know anything. I turn to any advice from the hive mind here. Thank you all!

It most likely did overheat. Many people continue to drive their cars thinking they can make it somewhere instead of pulling over and getting it towed.

Their is alot of labor cost to replace just a cylinder head( almost $5000 for a cylinder head job to include gaskets and labor) so the dealership is correct that engine replacement is better.

You can go with the dealer for $7000( is that just the engine or engine plus labor?) and have a brand new engine and maybe squeeze another 5 to 7 years out of the vehicle...if the frame isn't too badly rusted. Check your frame before you invest alot of $$$ in engine replacement.

However at 9 years old, why not just get a used salvage engine? The good news is used salvage engines for the gen 1 cx-5 are plentiful and only around $500 at junkyard. You can price then at your local salvage yard. And you can just pay a local mechanic $500-$1000 labor to install the engine for you. Check around for recommendations and pricing.

If you don't trust the dealer get a second opinion from another mechanic before you have any engine replaced. Maybe there really is something wrong with the computer. And check pricing on new engine versus salvage engine and make your decision.

a used engine is a risk...however
Most salvage yards warranty the engines for 90 days or even up to 180 days depending on the yard. And from my experience/knowledge, they've lasted for many years for friends/relatives. Also shop around a few different yards for the lower mileage salvage engine.

You most likely will only get a one year warranty on any new engine but it will be new.
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in summary, get a second opinion from a local mechanic or dealer, check frame for rust deterioration, then price used salvage engines plus labor(at a Indy shop) versus new at dealer, and finally make decision.

Check the coolant level when cold, top it off if needed and drive it until warmed up and the overheat light comes on . Park it and let it cool down for a few hours and check it ,if its now low you more than likely have a leak somewhere or a bad head gasket or bad head. A good shop should be able to test it and tell you what's wrong. I doubt the dealer miss diagnosed it . It my just be a bad head gasket ,and not a bad head. at any rat the dealer is not the place to have it repaired.

Lots of interesting information from the last 2 members.


Let me just say don't buy a salvage yard engine unless it has a warranty. The better option is to buy from a supplier that sells low mileage engine with a warranty.

Thats all folks. Anything else about what happen to your engine is all speculation unless the engine head is pulled which why would anyone want to do that at this point?

Welcome to the forum

thank you for the welcome, and advice. I am having another shop look at the car to let me know their findings on it. To me just seems weird that it would over heat and then not overheat, in my non-technical mind once overheated it should stay in that condition. But thank you and to all that inputted into this. Not sure what to do now with regards to spending the money and putting an engine in or junking out the car.

What I (service shop of better caliber) would have done was to check the ECU counters, pending DTC's and also the monitors. Then a coolant chemical test (possibly cooling system a psi test but that would be a call shot and what other observation I noted) followed by a cylinder compression test and then finally a leak down test. This would have point to the cause and condition of the engine.

I would replace the water pump belt (and I recommend this to everyone else). The belt has no tensioner; it's just an elastic belt. With heat and age it may start to slip meaning the water pump runs slow. This will cause overheating and will eventually cause head failure. I wonder if this is the reason that Mazda's seem prone to head failure? Your head might be irreparably damaged so this is really for everyone elase.

WELCOME TO THE FORUM

That is a good preventive suggestion! :cool:
But there is very little resistance force even at engine speeds upwards of 3k-4500k and if the belt was worn would slip at idle speeds and make a notable noise. I would guess about 4 years servicing dozens of *newer Mazda engines we have never replaced a bad one on a Mazda but have replaced them as a prior when servicing the main suppertime poly belt. I am referencing *Skyactiv gasoline Mazda engines
I might also add that if *coolant levels reached above 223F the check engine light would appear, you would have at least 1 or more DTCs and also if you had a coolant temperature gauge you would reference the high coolant temperatures.

I trust your experience but when I changed my belt it sure looks rinky-dink. Perhaps what we do learn here is when you get a high temperature alarm it's serious and if you keep driving you're asking for a new engine. I am concerned that the dealer said let's reprogram the computer. Overheating is not a computer problem it's a mechanical problem.