How To:Thermostat

[Vansquish]

I drove for about 4 months with a P0126, and highway cruising coolant temps in the mid 160s. It's probably not terribly detrimental to the engine to run at that kind of temperature, but it's probably better to get it taken care of earlier rather than later.

[Raider]

$40 from onlinemazdaparts.com, and then a few hours...

Or trade it in for a Speed 3...

[radioflyer]

Just did this a couple of days ago. It was not nearly as bad as I thought it was going to be. I had read people were removing the whole fucking IM to get to it, really glad I didn't have to go through that.

Bought the autozone special for $27. Low coolant temp problem solved, hopefully for good.

Overall took about 4 hours with an oil / filter change and OCC drain included in that time.

[mach69]

Originally Posted by BobTeatow Cleared P0126 but in test drive this morning in freezing CT, OBD/ELM/Torque shows temperature never going above 160F. So what are the risks of delaying thermo replacement? I'm not noticing any problems, engine running okay and cabin heat okay. Thanks, Bob T Mazda 3 / hatchback with 2.x engine, no-turbo.

The risks? Your ECT doesn't come up to the temperature it should (along with the oil). This will cause premature wear on the engine. My friend had a Mazda 3 with that code for months. Didn't seem to have problems from it, but he did sell it not long after he replaced the thermostat.

Originally Posted by radioflyer Just did this a couple of days ago. It was not nearly as bad as I thought it was going to be. I had read people were removing the whole fucking IM to get to it, really glad I didn't have to go through that. Bought the autozone special for $27. Low coolant temp problem solved, hopefully for good. Overall took about 4 hours with an oil / filter change and OCC drain included in that time.

Haha. And people thought taking off the PS pump was absurd. Taking off the IM... completely unnecessary. But if you do take off the IM, might as well clean the valves.

[pzr2874]

Thanks for the write-up. Might want to add a quart of PS fluid to the list. I lost about a 1/4 quart moving the PS pump.

[radioflyer]

wait. what.

you mean to say you disconnected the lines to the pump?! why?!

[Decepticon]

just did this an hour ago with my ms6..I didn't remove the ps pump nor the IM. The hardest part was sliding off the hoses from the thermostat. I unbolted the the bolts and took the thermostat off the housing first before taking the hoses off..I think this is the best way because it allows you to move the hoses around to get better access to the clamps. It was a tight fit getting the thermostat out and up while its still attached to the two hoses but there was enough space.

[radioflyer]

Originally Posted by Decepticon just did this an hour ago with my ms6..I didn't remove the ps pump nor the IM. The hardest part was sliding off the hoses from the thermostat. I unbolted the the bolts and took the thermostat off the housing first before taking the hoses off..I think this is the best way because it allows you to move the hoses around to get better access to the clamps. It was a tight fit getting the thermostat out and up while its still attached to the two hoses but there was enough space.

Lol! I did the same thing, I went through the trouble of re-attaching the thermostat to the block just to get the hoses off.

[skeeter149]

Originally Posted by pzr2874 Thanks for the write-up. Might want to add a quart of PS fluid to the list. I lost about a 1/4 quart moving the PS pump.

as a note on this speed 3 uses atf for power steering. i put power steering fluid when i did my fmic then read somewhere that it uses atf. drain and fill i did but i never had issues with the power steering fluid. but yes manual says atf.

[pzr2874]

Originally Posted by radioflyer wait. what. you mean to say you disconnected the lines to the pump?! why?!

I don't have the smallest of hands.

To add, Mazda changed the ATF to M5 and can be mixed with the old M3 ATF stuff.

[radioflyer]

Oh I see, I just kind of bent it out the way. I didn't bother actually disconnecting the hydrolic lines.

[mach69]

Originally Posted by pzr2874 Thanks for the write-up. Might want to add a quart of PS fluid to the list. I lost about a 1/4 quart moving the PS pump.

You are welcome. I did not remove the PS lines so I didn't need any PS fluid. I have big hands as well and just moved the pump out of way without having to disconnect the lines. More than enough space.

Originally Posted by Decepticon just did this an hour ago with my ms6..I didn't remove the ps pump nor the IM. The hardest part was sliding off the hoses from the thermostat. I unbolted the the bolts and took the thermostat off the housing first before taking the hoses off..I think this is the best way because it allows you to move the hoses around to get better access to the clamps. It was a tight fit getting the thermostat out and up while its still attached to the two hoses but there was enough space.

Actually, I had difficulty removing the hoses as well from the thermostat. I rebolted the thermostat back to the block as well. I used just one bolt, I put so much force on the plastic thermostat housing while trying to take off the hoses I broke the housing.

Originally Posted by radioflyer Lol! I did the same thing, I went through the trouble of re-attaching the thermostat to the block just to get the hoses off.

I did the same thing. I'll edit the how-to when I'm sober.

Originally Posted by pzr2874 I don't have the smallest of hands.

Neither do I. I probably bent the lines more than I should have getting the PS pump out of the way, but the lines seem fine. Palming a basketball with one hand ftw.

Originally Posted by radioflyer Oh I see, I just kind of bent it out the way. I didn't bother actually disconnecting the hydrolic lines.

I did the same thing. The hoses were flexible and made it easy to move the PS pump.

[pzr2874]

Once that was out took 15 mins to get to the butterfly clamps and change the thermo. Just another idea. Didn't think about riding the bolt out while pulling the pump.

I WAS DONE FUCKING WITH IT. Thanks again.

[DynoBunny]

I don't see how you guys got the god damn belt on by yourselves.

[pzr2874]

Originally Posted by DynoBunny I don't see how you guys got the god damn belt on by yourselves.

I had to have a friend loop it over the PS pump as well. Some ppl have ape arms.

[DynoBunny]

Yea waiting on the wife to get home, fuck that shit.

[miklo13]

i have p0126 on my ms3 u guys saying that is the tt

[radioflyer]

yes

[Raider]

[spals]

Thanks for the write-up. I threw a P0126 on my way back to Dallas from buying the car in Austin. Got home yesterday and ended up replacing the thermostat. CEL hasn't returned and the temp gauge has returned to normal.

One thing that you might add that stumped me for five minutes is that when you remove the electrical connector from the power steering pump you need to compress the clip to get it to release. I tried to pull the tab out of the connector and it wouldn't release from the sensor.

[p057]

I've done the serp belt replacement by myself. without any issue. trick is using a LONG thick flathead screwdriver. and a long ratcheting wrench, hold that with your foot to keep the tension pulley off. LOL.

My ECTs are starting to dip to 165 during highway cruises. It gets up to 190-200 easily if i'm ragging on it or sitting in traffic, but i'm sure i need to replace it. Hopefully in about a month. (hopefully the goddamn house closes by then!!! ARGG!)

Thanks for the guide, i think this will be my first repair in my brand new garage.... along with valve cleaning, IM spacer install and CPE seals install.... hahaha, gonna really break that thing in!!

[mach69]

Originally Posted by DynoBunny I don't see how you guys got the god damn belt on by yourselves.

Its easy. Grab 14mm and 15mm combination wrenches. You are going to put the box/closed end of the 14mm wrench onto the tensioner. Before you do that, wrap the box/closed end of the 15mm wrench around the open end of the 14 mm wrench. You get a lot of leverage with this. Pic below. I know its a shitty cel phone pic, but you get the idea.

Once you have your wrenches wrapped around each other, put your serpentine belt on every pulley except the crankshaft pulley. Loosen up the tensioner with your left hand and force the belt over the crankshaft pulley with your right hand.

Originally Posted by spals One thing that you might add that stumped me for five minutes is that when you remove the electrical connector from the power steering pump you need to compress the clip to get it to release.

Done. Even used your exact wording.

Originally Posted by p057 Thanks for the guide, i think this will be my first repair in my brand new garage.... along with valve cleaning, IM spacer install and CPE seals install.... hahaha, gonna really break that thing in!!

You are welcome. Valve and IM cleaning, VTCS delete, EGR delete, and TB coolant bypass is my next 'project'.

[Jeter_1]

Subbed for easy reference..

[CaptainCode]

Did mine today. No way I could do it without unbolting the power steering pump and moving it out the way. That thing was a motherfucker to get off. Bolts were quite difficult to get off, especially the bottom one. Tensioner belt was also a huge PITA to get back on but I did it without help. I got 1 gallon of FL22 from the dealer. Looks like I might need to add a little bit of distilled water but not much.

Thermostat was quite the rip compared to some of you guys(I live in Canada, bought OEM from the dealer). It cost $79+tax. Went and looked at Part Source and they weren't much cheaper for the aftermarket one.

The swap took me 4 hrs.

Thanks for the how-to!

[He Hate Me]

*Edit*

Don't buy the Stant from Pep Boys. The main inlet is 1" longer, thus going right into your A/C line.

[new_speed]

This was a great how to! Only took me like 2 hrs to do this install. Thanks!

[meelo88]

Great How-to, did mine in about an hour only took off the intercooler cover. Extensions and thumb ratchets saved my butt!

[dougpt10]

2008 and the fan has been running crazy the last 3 days. Just today notice engine temp running hot and A/C warm. Burped the system and A/C was cold for a few minutes but then went hot and engine temps rose again. Sounds like the thermostat is bad?

[a2j7]

Thanx for the photos and instructions mate, worked like a charm thanx to your help. New thermostat
and house plus sealing ring $135.00 au.

[mach69]

Originally Posted by dougpt10 2008 and the fan has been running crazy the last 3 days. Just today notice engine temp running hot and A/C warm. Burped the system and A/C was cold for a few minutes but then went hot and engine temps rose again. Sounds like the thermostat is bad?

How did you burp the coolant system? I ask because there is no radiator cap. The coolant is refilled through the coolant reservoir which has its own way of bleeding air from the cooling system.

The fans staying on was a clear cut sign for me the system was running hot. I also would monitor my temps and even on the highway I was at 220+F. My A/C never went warm. My engine temp gauge in the gauge cluster never went above the usual spot.

Do you have a way to monitor the ECT? I have a dashhawk and that is how I noticed the temp.

Easiest way to check the thermostat is to touch your radiator hoses. After a longish drive touch both hoses. If the top hose is HOT and the bottom hose is cool, your thermostat is not opening.

I'm not sure if the engine running so hot would cause the A/C to run hot, you may have two problems. Possible low on freon in the A/C system?

[CBRKnightRiderS2K]

Thanks for the write-up! Took me 2.5hrs to complete! I had to take off PS pump.

[bertrand_CX_7]

Did Mazda ever issued a recall or at least a TSB on this thermostat issue?

Because such a high failure rate on thermostats is normal, specifically with the low milenage they are failing.

[Raider]

Nope. Actual failure rates are unknown, we are a fraction of total produced, and part is $40.

[bertrand_CX_7]

Originally Posted by Raider Nope. Actual failure rates are unknown, we are a fraction of total produced, and part is $40.

Hey raider do you know if the thermostat for the CX-7 is the same as the one for the Speed3?

So got mine from Mazdamotorsport and the part department at the dealership confirmed that the part number for CX-7 and speed3 is the same.

The internals on the new one seems a little different from the OM one that was mounted on the CX-7.

Can you or anyone confirm?

Thanks

[Raider]

I know there was a revision made, based on posts.

IMO when mine went out, I took it as an excuse to clean the valves. $40 part, NCE. Now the VVT and turbo, well that just pissed me off when they capped miles at 70k.

[bertrand_CX_7]

Thanks man. This will confirm the difference. Just attached a pic to my previous post. Thanks for the heads up.

[bertrand_CX_7]

Autozone just confirm it's the same part number for both cars.

Part number is 51280 for the CX-7 and cost $26.99@ autozone. I'll highly recommend anyone to get the OM part from a trusted vendor $26.99 sounds too cheap to me and I'm concern with the the quality.

Obviously you don't want to save $$$ on engine parts.... FYI I paid around $40 for my thermostat from Mazdamotorsport and I believe those are genuine parts....

[a4tek]

great write up i might be doing this next week

[kidrabbit84]

Originally Posted by He Hate Me *Edit* Don't buy the Stant from Pep Boys. The main inlet is 1" longer, thus going right into your A/C line.

+1 - just ran into this with Napa, O'Riely's, and Advance Auto. All they have is the long neck one. I thought I would try aftermarket instead of the Mazda part that crapped with only 62k. In the end I finally ended up with OEM.

Anyways you might want to take a tape measure with you if you don't have the old one pulled yet - see below.

[kidrabbit84]

Correct T-Stat on top and wrong on bottom:
20140122_071939_zps6b65ce65.jpg