CX-5 no heating
 

I’m not sure if this is common or not, but I’ve found that I no longer have any heating in the car, just air con.

I put it into my usual garage and they thought it would be an easy fix and it turns out they can’t really help now. They checked the coolant and replaced the thermostat as the engine wasn’t getting warm enough so 1 problem solved but still no heating.

mazda will plug it in to see if they can find a fault but they’ve given us a price tag of £1400 to fix worse case.

I can’t help but think this will be a common Mazda problem as we’ve already had the turbo go at 30,000 miles (thankfully under guarantee) and they’ll be robbing us! Currently sitting at 61,000 2014 model

any ideas? Thanks

Definitely not a common problem. I personally haven't come across this problem on a CX-5 & I've been working with Mazda since before the CX-5 was launched.

Sounds like hot coolant isn't getting to the heater core. Could be a blockage in the system or could be air in the system which needs to be burped. If they replaced the thermostat, air is a possibility. Other possibilities are the blend doors in the heater or something preventing the heater controls from activating the system properly.
I'm not that familiar with the CX5 heating/cooling system as mine has always worked fine, but those would be the areas I would check first based on other vehicles I've had.

These are all good suggestion :)

except there is not an air in the system. I can safely say this because the way Mazda as most engines (specifically the head design) and engine bay configurations from about 2000 and newer has all but eliminated this happening. There are a few engines that still had this issue none I am aware of from 2005 and newer of the top auto manufactured platforms and models? The biggest problem was in head designs that cause steam pocket to form creating super-heated condition. But that also followed a few other issues that went along with that as well.
Besides I am going to say it and it is always hated on forums LOL there is always air in cooling systems anyway. think about it the coolant is a mixture of water and H2O . And the O is what?.....;)

Air bubbles in the cooling system are an issue in the MX5 NC engines. I don't know about the ND's. The issue isn't usually a big problem, but burping them can be a bit of a PITA sometimes. You can speak better about the SkyActiv ones though.

I have had a car that didn't heat well. I occasionally took the heater hosed off at the engine and
used a garden hose, low pressure, to flush back and forth a couple of times to 'fix' the problem.
Needed a new heater core but didn't have funds or time to correct.
My 2¢

Ok good info..... I actually added to my personal program on service information Thanks.

https://cimg6.ibsrv.net/gimg/www.maz...bb2bc5b895.jpg


Generally, it is during a thermostat change that bleeding at times is a challenge. I always try to use a brand that has a jiggle valve. If none I drill a small hole in the flange. With some troublesome engines I do is raise the front of the vehicle about 10 degrees. Start the engine with radiator cap and let the engine get to operating temperature. Fill replace the cap and test drive. If the temperature is erratic back to the shop and remove cap when pressure is low and repeat. So ya at times a PIA at times .

The NC MX5 issue arises as the heater core is higher than the rest of the cooling system. Ergo, to burp it, you need to raise the front of the vehicle to lower the heater in the system. I have ramps that I used to use, but, since my back has gotten so bad, I just have my mechanic worry about it. Luckily, I've found a good shop with a good reputation and have had good results.

Except that the problem existed before the thermostat was replaced. Doesn’t mean it isn’t air in the system, but I would be looking for another cause too.

What most don't realize in when steam pockets form from air in a cooling system in some head designs, they super heat the water around them. So, if air is in a cooling system the likelihood is your cooling system temperatures will also show higher than normal. Air in a cooling system does not obstruct the flow of coolant or water. Let's not forget that some water pumps produce variable water pressure and some as the engine speed increases so does the water pump speed which also increases the flow of water.

Air in the system is more old school from a couple or more decades and older ago and really most of the time it was caused from not doing a colling system procedure service properly.