Overheating what havent I changed?
 

So I have been overheating it has been about 100 every day. I have put in a new water pump, thermostat, mishimoto radiator and fans and cap. Also I am running 90/10 water/anitfreeze ratio. What am I forgetting?

Put the undertray back on.

Dann

Are you losing coolant? Is it overheating when stopped or driving? Is your fan coming on?

All fans are good and im not loosing any coolant. Runs at about 195-200F at a sitting still with ac on. Under boost or at speeds at 60-70 the car gets to 230F and will keep increasing if I were to let it. I ordered an undertray and and new temp sensor. If that dont fix it I am completely at a loss of what to do. I understand a coolant re route helps but I am not even driving the car hard and it overheats.

have you bled all of the air out of the system?

If you just "ordered an undertray", am I correct to assume that you don't yet understand the concept of "ducting"?

OP, you realise that with no further info except that you dont know why it overheats and that it does infact overheat, I was able to deduct that you were infact missing the undertray, immediately, with no hesitation and full confidence.

If someone can do that, whats the chances that they are right?

Dann

[/thread]

Yes I bled all the air

I understand I just didn't realize how crucial it was on a street used miata. Sometimes it over heats just going 40mph or les. Didnt think ducting would be so crucial as to lower 230f temps at such low speeds.

You may have other issues. But it's a given that you need to use the under panel.

I don't understand what other issues I could have I figure underpanel and I ordered a new temp sensor. Replaced everything else.

Air in system?

nm see you said you bled the system.

I'm willing to bet the panel fixes it. You would be surprised how much of an impact it has.

Make sure your fans are rotating in the correct direction and get more water into the mix.

How did you burp the coolant? I would suggest going on amazon and getting one of the magic funnels to use for burping.

I followed the same procedure similar to that of the mishimoto YouTube instruction video for installing the radiator.

Fans are good. Is it safe to run less than 10% antifreeze. Oh also I forgot to mention that I tried wetter water and it didn't really do much. I did wetter water and water mix.

I started thinking would the panel also help at idle as well? Maybe act similar to sucking through a straw? Increase air velocity by allowing the fans to pull air better?

How are your fans mounted to the radiator?

I would suggest putting the undertray back on, since it's the only suggestion in this thread that's going to actually fix your problem.

While you're waiting for the undertray to arrive, you should be running 100% distilled water plus a bottle of Water Wetter, and disconnect the signal wire to your ac compressor. Once you do that, turning your AC on (and having the cabin fan control in 1 or higher) will turn on both your fans, which should bring those temps way down at low speeds, and may help at highway speeds as well.

C

You still running the FMII setup? I'm going back to NA, and if you like, you can have my undertray, which is already cut for an FMII, cheap, and I'll buy the new one off you. My car is off the road pending an engine swap, so this could be an immediate solution for you.

C

I am already running fans in paralle. I followed hakunas guide over on m.net. it help but still. I bet the undertray will fix it because Savigton said so. Just a waiting game at this point. I also ordered stage 2 fan shroud from fm this morning just cause. I read lots of reviews and to be honest the mishis blow lighter than the stock fans. Originally I only got them because when I was na I couldn't fit the intake that well on my 91 at the time. The fans were ok most of the year when I was still na. My friends gonna buy my mishi fan.

I don't trust cheap aftermarket fans either. I took the time to trim my stockers so they'd fit with my Koyo55 & FMII, after being less than impressed with the Partzfinder strap-on fans.

Try the AC trick though - just disconnect the compressor trigger wire, and your fans will turn on from the AC button.

C

I do find it funny that my 93' at 10psi in 118 degree weather with no undertray, 1 fan, koyo radiator doesn't go above 180 on the highway or in stop and go traffic even when pushing it hard.

Is that using a stock fan?

That is with 1 slim fan. As far as I can tell it's a no-name fan, held on by those push through zip tie things.

This is the that I recommend to get to help burp coolant. I am not saying I do not think the missing undertray is the issue, this funnel will just make burping in general much easier.

you should be running 10:90 antifreeze:water.

and put your undertray back on and seal the mouth.

90/10 vs 100% distilled + Water Wetter, which one reigns supreme?

C

at that point, you have bigger issues.

???

I believe the consensus is that pure water provides superior cooling performance, but that for street cars, adding some antifreeze is necessary for corossion protection.

In my non-turbo '90 (with no undertray, stock radiator, etc) I run appx. 30% antifreeze.

Water has better thermal conductivity than coolant, and Water Wetter, Purple Ice, etc advertise that they cover the corrosion & lubrication issue.

C

Unless I misread the first time, you are running 10% water and 90% antifreeze; just the opposite of what you want.

How is it possible to use 100% water and then add water wetter on top of that??? Your radiator would be overflowing and shit!!!

If you want the ABSOLUTE BEST COOLANT POSSIBLE then fill that fucker with 100%compressed liquid ammonia. No shit.

But in the real world, water is the best coolant because of its high specific heat (liquid ammonia has a 40% higher specific heat at 212* :P ), water wetter does indeed add a level of corrosion resistance, but the primary purpose of water wetter is to break/reduce the surface tension of water which results in greater surface area contact between metal and water at the molecular level...apparently.

Edit: Put your undertray on.

if he's having issues with 90% water, he's going to have issues with 99.9% water + 0.1% wetter.

Every post that doesn't include the words "put your undertray on" in this thread makes me cry at night.

I wonder how many people actually use the undertray. I'd imagine a lot of turbo'd people do not with the extra cutting required (horrible excuse I know). I fully "intend" to run mine as I know the benefits. But I bet there are a lot of people who "intend" to put it back on too.

Is that the correct order?

I think he wrote that wrong. Because later he asked if it was okay to run less than 10% antifreeze.

I don't run any antifreeze. Bottle of water wetter, the rest is well... water.

nope fixed it my bad I am running 90% water 10% antifreeze.

Do you have an A/C condensor infront of your radiator, and if so do you have your A/C turned on?
Mine stays in the ~200 range (I think the coolant re-route I bought has a 190 t-stat) as long as I have the A/C turned off. Once it's turned on, on the highway I see temps in the 225-228 range at speed.

No A/C at all. That does help quite a bit I'm sure. No reroute yet though. Although with better coolant routing, extracting more heat from the engine, wouldn't the coolant temps increase a smidgen? (spoiler alert: I know nothing of thermodynamics or whatever voodoo is involved in figuring that out).

At cruise, what is the "dangerous heat" level for you all? Obviously we would like our temps to be about 185 degrees once all the proper ducting, undertrays etc are in place, but what would cause you to either shut the car down, turn the heat on, or pull over?

If I stay at 212 or above for any period of time I get uncomfortable.

225F for the MSM.


Depends on the car though.


My MX6 has had chronic cooling issues over the years and i've seen as high as 270F sitting in traffic. O-ringed block, copper gasket, and ARP studs torqued to Jesus and back, no fucks given. Still nails a compression test, so.... meh.

With a 14psi radiator cap, the boiling point of water is a touch north of 245*F. At 235*F, I turn my A/C off - but I would have to be parked and idling in 100* heat with the A/C on full blast for 15 minutes to break 230*F. Once the A/C is off, temps while idling drop down to about 215 in about 120 seconds, then I get another 15 minutes of A/C. My dash gauge starts flashing me at about 227* I think.

While making any speed whatsoever with the car (25+ mph) I'll never see a problem.

It doesn't matter how hot your coolant is, your engine will be fine as long as there is coolant there and circulating. It's the lack of coolant that kills engines, usually from boiling.

I did this to a car that was having the same overheating problem that you are having, in his case the coolant RR (i assume that you have one) was not burping air from the highest point on the engine to the radiator where it could be vented to the catch can in the heat-cool sicle. i used a clear hose initially and could see a lot of air coming throu it for the first few minutes after start up.
The car whent from consistantly overheating to a painted temp needle.
Hope that this helps
https://www.miataturbo.net/attachmen...ine=1376438463

I ignored everyone's advise to "put your undertray on" when I built my turbo '92, and had no cooling problems with it until I moved to FL, which a rear-thermostat reroute cured.

Based on that experience, I have not purchased a replacement undertray for my bone-stock 90, which continues not to overheat.

I really don't want to do a coolant reroute. I have my reasons. I am hoping this weekend when I put the new temp sensor that will fix it and if not I hope the shroud does. I just need to baby the car from Tyler tx to san Marcos tx(3.5 hr drive) until I get higher flowing fans in. Fm spal setups on backorder :(

How do you expect a temp sensor to fix your overheating issues? Temp sensors read a temperature that already exists.

If the old temp sensor is reading incorrect, and showing the temp well higher than it should be. Then a new temp sensor will fix the overheating problem!!! :LOL:

Are you getting bubbling from the coolant overflow bottle? If yes and the fans are running a new thermostat wont fix it.

Oy.




Is this where we ask the question of "How do you know it's overheating?"

You know what your problem is? You need the hyper reroute.

The coolant is not bubbling out so.....


The reason I say the temp sensor is because it may be bad. For all I know my temp is fine and the gauge is broken.

Anyway before I go blow 250 or so on a reroute(unless anyone knows of a cheaper place other then begi) I plan on ducting and higher capacity fans. I feel it will be a better next move.

How about an undertray? Have you considered running one?

Thats not a bad idea, it would have been much better if someone suggested it immediately in the first reply though.

Dann

Read the diy reroute. Search n00b!