Mazda 6 Forums banner

1 - 11 of 11 Posts

·
Registered
Joined
·
1 Posts
Discussion Starter #1
Just over a year ago, my 2006 Mazda 6i (auto, 2.3L, 106K miles) threw a P0126 code (Insufficient Coolant Temperature for Stable Operations) for the first time. It happened while I was driving on the highway, so I stopped at a Jiffy Lube and had it cleared (this happened a total of 3-4 times during a 7-hour drive). It then went off and didn't come back on again until yesterday (also while I was driving on the highway). The heat works fine and the temp gauge needle always gets up to the middle while I'm driving. I've read multiple threads that indicate it's most likely either the thermostat or coolant temp sensor, or could also be an air bubble, coolant leak or a sign that the water pump may be going bad. Anyone else experience the same problem and/or know which issue I should tackle first?

Thanks in advance!
 

·
Registered
Joined
·
2,660 Posts
I've read multiple threads that indicate it's most likely either the thermostat or coolant temp sensor, or could also be an air bubble, coolant leak or a sign that the water pump may be going bad. Anyone else experience the same problem and/or know which issue I should tackle first?

From your list; I place my vote on a faulty connection like a bad ground or A BAD CONNECTION to the sensor itself. I suggest you find the sensor and confirm the connection is good clean, no corrosion etc.

coolant temp sensor * This is a maybe. But more than likely its the connection to it
thermostat * T-state would have to stick open. Rare but it could happen I suppose.
an air bubble * If low enough on coolant the temp gauge may not register. Check the coolant level.
coolant leak * you can see this and smell it.
a sign that the water pump may be going bad * Negative, not sure where that came from unless once its doomed it leaks the fluid out which a water pump can do if neglected.

You say it blow hot air just as before?
 

·
Registered
Joined
·
4 Posts
Well, Final Impact I sure hope this notifies you when I post on here... I am obviously an all around newb. I don't mess around in any forums, etc. Got my very first Mazda this Friday night and I must say I am impressed BUT I am having this same code reading... Drove approximately 50 miles after clearing all codes - check engine light came on and it was this lovely coolant temp one. Checked antifreeze (I know - SHOULD have done that before ever driving around or purchasing) and it was very low. So, I refilled said coolant reservoir. Have driven about 45 miles and the same code just popped back up. I was driving it so no I have not checked the coolant again but I am almost certain I am losing it. I have had no puddle underneath the vehicle and do not know where to look to check for leaks. I am also bothered by the fact that despite the code reading my gauge still shows dead center. My initial fear is head gasket but I do not have a lot of visible exhaust or anything. I have heard maybe a heater core but the last time I had a heater core decide to crap out on me it flooded my passenger floorboard. Help me - I know I am moderately ignorant concerning this but I don't want to go jump at a car repair place completely oblivious.


****Just went and checked coolant level. Cannot see any fluid in reservoir yet radiator is tip top full. I'm all the more clueless.
 

·
Registered
Joined
·
2,660 Posts
@starlight,
What car, how many miles, what engine, what trans, what is the overall condition as best you can describe it?

Continue to top off the reservoir after every run cycle to get it full and keep it full. Taking note that plain water will evaporate, rust, and has no lubrication for the water pump seal.
If your model has an F22 on the radiator cap, DO NOT MIX regular ethyl glycol as the two are not compatible. ^^ All of that is about getting it stable so we can compare apples to apples. If its completely full of coolant, has no air in the system, blows hot air at the dash, and the needle is in the "warm" region, now we can look at why it throws a code.

P0125 Excessive time to enter closed loop fuel control ON 2 CCM (See DTC P0125
P0126 Coolant thermostat ON 2 Thermostat (See DTC P0126, P0128
P0128 Coolant thermostat ON 2 Thermostat (See DTC P0126, P0128

So yours it throwing a P0126? In this case the car thinks the T-stat is stuck open. So, the sensor is not getting above 160F when driving at speeds of 20+ mph.
I'm going to assume your driving a 2.3 sadly, not sure where the sensor is on the L3 engine. But I'd remove the wire from it, inspect it for corrosion and put it back once the system is full of water....

That's about it for now. Let me know what you find. Add @Final Impact to this post.
 

·
Registered
Joined
·
4 Posts
Yes 2.3 is correct. Title calls the model M6I... It's a 2006 with 124K miles. Overall condition seems acceptable. Middle aged woman was driving it and judging by the fact that it has four different tires she didn't do much more than what she deemed as necessary. Shifts well. No strange sputters or hesitations. Slightly rough idle. There is some slight bumper damage where she says she hit a dear :/ I don't know what she really hit but I was curious as to whether it could have jarred something loose. I did have to tighten up connections to the passenger side headlight... I know this sounds ignorant but any hint as to what the sensor might look like or should I just google it and hunt it down?
 

·
Registered
Joined
·
2,660 Posts
Hood up, looking at the engine, its on the right side next to the transmission below the valve cover. Appears to stick straight out.
2.3_ECT Sesnor.jpg

I could be mistaken about it throwing a code for bad connection. If that is true these could/should be present.
P0116 Engine coolant temperature circuit range/performance
P0117 ECT sensor circuit low input
P0118 ECT sensor circuit high input

Is it full of coolant and blows hot air?


This is NOT your engine, but the V6 2006 has a grey connector with a white and orange looking wire coming from them. Do not TWIST the sensor. The V6 one is screwed in and could come out by twisting it and dump hot fluid on you. Just push the clip in and pull straight up. Should look something like so...
Far right of picture, mid section:
 

·
Registered
Joined
·
4 Posts
Blowing hot air just fine. I have to go grab some more coolant and refill the reservoir but radiator itself is full. When I get the coolant I am going to check that connection clear all the codes and then see what pops back up on me. May be a little bit. Work is a bit hectic and lunch may come a little late I reckon. Thank you for the picture. I feel like a simpleton but it definitely helps me ALOT. I am not accustomed to this...

P0126 is only code it is throwing.
 

·
Registered
Joined
·
2,660 Posts
How are you easily clearing the codes - lets just say, not all of us come fully equipped to do such things! Some codes clear themselves after 3 successful start, run, warm up and shut down cycles. This code is set by run time conditions and may take longer than 3 runs to clear itself depending on what you use the car for.

Anyway - be sure to heed the warning about the F22 Coolant and DON'T Mix them if your CAP says F22 on it. If your coolant looks goey, slushy, thick, or brown, it needs flushed. Also keep track of how much coolant you added. More than three quarts and may just be it was low on coolant.

So this was a private sale? Craigslist or something??

let me know if you need help find the sensor, verifying coolant types, or what ever. No question is foolish. Don't hesitate to use the search function.
 

·
Registered
Joined
·
2,660 Posts
Slightly off topic -
I would take it in and have all the fluids inspected and get a second opinion about the general maintenance condition. If your goal is to keep this for years, get the oil changed, coolant replaced, brake fluid bled, brake pads inspected, power steering fluid flushed, and if its an automatic, dump the fluid out.

You have any mad skills, friends with basic skills or a place to do such things?

Inspect the transmission fluid, it should hold a pinkish hue and not smell burned. If it smells burned, it needs replaced. Also check the level, engine on, car warm and in PARK. Remove stick and wipe it. Dip several times and confirm both sides of stick match levels.
With the engine off, remove engine oil fill cap. Is it clean inside as in bare bright shinny metal or is it black and gooey? If the later, it will need several oil changes ahead of normal schedules.
Let start a new thread if you see a few things adding up.
 

·
Registered
Joined
·
4 Posts
I am a spoiled brat that works at a diesel mechanic shop that has a boss that likes to get different little scanners and voila one works perfectly with my car so I have temporarily kidnapped it until my vehicle is behaving correctly. I tinkered around with wiring and pulled all kinds of things apart and made sure there were all good clean connections to everything I could reach since that was my issue with the headlight as well. I eventually tired of it so I took it by an old mom and pop shop down the road at lunch and talked about it and he advises I replace the thermostat before I go any further on anything else because his reader was showing that it is actually running too cool and not allowing it to reach it's optimum temperature - thus the "insufficient temperature" I took as meaning too hot actually means it won't let it get warm enough. I do have access to plenty of tools and can drum up a labor force if need but am considering just taking it back to the gentleman I talked to about it because he said he would charge around $100 in labor. I think it's worth me not having the headache. It was just a simple cash deal from a friend's aunt. She has had it since it was brand new and has a new car and has just had this one sitting around and used for running to town ever so often. Oil looks good. She did just change it in late October. I probably will go ahead and change ahead of schedule a few months in a row just to be safe. Depending on where the transmission fluid can be drained from I will decide whether I want to figure it out or if I will maybe trade some food to one of the guys I work with to do it. Now funny thing - I am not familiar with Mazdas but my insurance company is pulling it up as a mazda 6 s sport sedan... Title says mazda - M6i. What is the difference? / Does it matter?

Oh and since we are off topic - what do you think about replacing the timing chain. I have a few people dead set on needing to change it and even more others telling me it is silly to rip into it for no reason.
 

·
Registered
Joined
·
2,660 Posts
S vs i, that gets you 2 more cylinders in a V config! Much like the one I drive (3.0 liter V6). Someone needs to pull their head out....... Well, you get the idea. The vin is pretty clear about what it is and is not. Likely only your gas bill! lol

As for the TC - if its noisy, its not likely the chain but the chains tensioner. It may be worth replacing but if its not a sludge motor that was neglected, I'd leave it be.

back to the issue - if $100 spot gets it flushed, you might just do that. Historically stats don't stick open, but there are the exceptions (its over cooling and not reaching temp fast enough). This impact emissions and fuel economy as well as increased catylist temperatures...

So how much coolant was added // TOTAL AMOUNT? // If it was really low that could have been the whole problem.

I've tagged my better threads with JJD952 and there are some on transmission draining, coolant issues, maintenance issues. Take a look. Also a link to FSM so you can get the shop folk to do it right as opposed to just winging it! lol

Good luck and keep us posted - but I'd drive it for a bit and see if once full its OK!
 
1 - 11 of 11 Posts
Top