So a little update... I took out the intercooler, radiator and looked at the AC condenser to see if there were any obstructions or bent fins causing the lack of airflow. All seems good so my next step is going to be going to Home depot to pick up stuff to create better ducting. I am also going to put in better flowing fans and I am getting rid of the aluminum shroud so it will be on the classifieds soon. After browsing around it seems that there are some issues going on with my current setup as 1. the mishi fans have low CFM and 2 the aluminum shroud prevents air from flowing rather than moves air on the highway from flowing through the radiator. When I think about its design its almost like a metal parachute trapping hot air.

have you tried bolting your stock fans back up? sounds like you have a shroud that blocks a majority of airflow.

also, you sure your stat isn't failed?

My stock fans broke a while back and my dumbass self threw the shroud away with it. I dont have a t stat in my car. Ever since the first time it overheated I took it out and never put it back in. My buddy ran his NA miata last winter without one and it didnt take too long to warm up with out it. The winters here dont get that bad to necessarily have one.

Your buddies aren't helping you.

Is that a question or a statement?

My friend lives in Dallas as I moved to San Marcos. If your implying that not running a thermostat is a bad idea. I don't understand how it can really hurt other then warming up the engine faster.

The thermostat is there first to warm your engine to operating temperature and then to hold it there by allowing water to go through the radiator. Running without a thermostat in a standard setup will cause the water to circulate more into the radiator and will cause the engine to overheat because of lack of circulation.

Put the thermostat back in!

This is the EXACT problem I am having... Idling with AC on stays at 200, get on the highway and up it goes to 230. Keeps going up if the AC doesn't get shut off. Without the AC on, on the highway I stay @ 220.
My cooling sytem:

FM's older aluminum radiator.
M-tuned reroute.
FM spal fan kit.
90% water 10 % coolant.
Thermostat replaced with 185* unit. No change in problem.
Stock undertray.
Trackdog intercooler with all the shrouding.
System burped properly.
Water pump replaced less then 10k miles ago.
No leaks.

I measured with a pyrometer several places in the cooling system one morning before running the car, everywhere I measured was within 1 degree of what MS was showing.

Something to note though is that my stock dash temperature gauge never goes to 12 o'clock or past... Anyone know at what the stock gauge will continue to rise? Not sure if knowing this will help eliminate and problems with sensors... bleh.

What kind of shrouding do you have? Can you take a pic?

I want to say the stock gauge doesn't start to move until ~235-ish

I cant fit the thermostat in because the Auto meter temp sensor will not fit with it in. Its either one or the other. I actually seem to be running cooler without the thermostat in. What I mean by that is after driving a couple hours it caps around 215-225 with ac off. Where as when the thermostat was in it was getting up to 245-250. I swapped in two different thermostats and got the same thing. All together I tried a 160 degree and two 180 degree thermostats. I confirmed all readings through megasquirt as to maintain a constant variable. Thermostats were installed according to BEGis instruction for the coolant reroute.

Luke this scares the shit out of me. Im glad I am not alone but sad that you have to be in the same boat as me. Hopefully we get it figured out. Oh and yeah my stock gauge starts to move around 235-240 degrees.

I stand corrected. Your first post in this thread stated that you had the thermostat in place and a standard setup. In the standard setup you starve the back of the engine of cooling if you remove the thermostat. I missed the later post where you had done the reroute. What did you do at the front of the engine when you did the reroute? Block it? Maybe some pictures of where you are now would help on the fans and reroute.

What?

The thermostat is important in order to warm the engine up to normal operating temperatures sooner, which helps, among other things, to bring your oil temperature up to operating temperature quickly. If detonation is like a bomb for engines, cold oil is like a slow cancer. Without that thermostat letting the engine get nice and toasty, your engine oil stays colder, and your spinny and slidey parts wear faster.

I can see no situation in which the lack of a thermostat could possibly make the car run hotter, with the possible exception of of very slightly lowering the pressure inside of the block which might allow boiling - but probably not.

Edit: Oh yeah, sorry, I missed the "standard setup" part of your post... which makes your post accurate. I was confused because I had my understanding connected to the "rerouted setup" in this thread. Carry on. :beer:


Regarding running the car with A/C all day at 200, but shooting to 235++ as soon as you get on the freeway, I had this exact problem, I did everything in the book, put on massive SPAL fans, big fat koyo radiator, coolant reroute, tried several different thermostats, restricted the heater flow coolant path, added some sheet metal for "ducting", bought and installed an expensive carbon fiber flyin' miata heat extraction hood, rebuilt the undertray, etc., etc.

The reason that we tell people that they must do proper ducting is because it is the one single proven method that works to eliminate freeway heat creep EVERY TIME. Nothing else will solve this problem. If you ducted your radiator and you're still experiencing freeway heat creep, then you didn't duct well enough. You can do a shitty job and it wont fix your problem, you can do a decent job and you probably wont see a difference, you can do a good job and you might blow me off when you still see creep, but only slightly slower, but to see the results you are looking for, you MUST do a "great" job ducting. It doesn't have to be "impeccable", and it doesn't have to be "perfect", but if you, for a split second, decide that you've done a "good enough" job, I'm going to tell you: "It ain't good enough".

While removing a fan shroud might make a small difference if you have small shitty fans, if you have decent sized, quality fans that cover the majority of your radiator surface, and your shroud has "stand off" allowing the fans to draw air from the covered portion of the radiator, your shroud/fans are not creating a limitation on your cooling system on public roads...ANY public roads...that aren't in Germany.

I now have the opposite problem. When I'm driving on the freeway in 90+ degree temps with the A/C on full blast, my temperature never climbs above 185*... just so you're aware, at 185* my 180* thermostat is regulating my coolant flow because my radiator cools "too well". Once I stop, though, my temps start climbing to 225*+. My problem isn't a mystery though, after doing a lot of duct work, my fans have too much standoff from the radiator now, a little bit of metal bending will quickly fix that up, but I've lost too much fun summer to worry about it now, I'd rather just enjoy it for the rest of the summer and fix it in the winter.

I don't really understand this.
Anywho...
I will get some pictures this evening and report back.

Im not sure if he is talking to you or me.

I am not sure who you are talking to... :party:

:fawk:

Thanks, I'll get that.

TSE radiator. As far as ducting, I'm curious why you think that's key when parked?

So I did some ducting and put in some siliconeintake fans rated at 1600 cfm. I refilled and burped somewhat. I then took it for a drive and it begain to boil over and over heat.(on highway and street) I went a head and put it up in the garage going to wait till it cools off and refill it back up with coolant and see if it over heats agian. So far im not feeling too optimistic about it. I took off the front bumper and used thin alluminum sheet from lowes to duct and I added a cooling plate to try and box everything in. The fans seem to be pulling a good amount of air through the intercooler. I can put a piece of paper on the intercooler and it will pull enough air to keep it attached. Any Ideas?

EDIT Also want to mention its 100 degrees out

I wonder if you have a headgasket issue. It's time for a compression / leakdown test.

C

You probably did a shitty job on the ducting. It took six pages of bullshit to get here, where you should have started?

Also, you will receive no sympathy from us until you procure His Majesty, Magic Funnel.

Wouldnt I be losing coolant if I had a headgasket issue?