Did you massage the hose to the radiator inlet to help push any entrained air along?

Also, why force everything through the intercooler first? Open that up

 

I suppose but its literally brand new. less than 100 miles

 

im gonna change the fan out, jack up the front and bleed it some more

 

It's pretty clear that your fans don't move enough air to cool down at idle, specifically the non-stock one.

 

I vote air. The radiator neck should be inches above the heater hose/tube connection, not just the cyl head. Run the engine with the heater on blast while the nose is up. If I were you I would drain and refill it, as to start fresh with no air pockets already formed.

 

Well ****. I took the ebay fan off and realized I had it wired as a blower not sucker. Put the oem fan on and have the front jacked up, cap off and running. Will report back soon.

 

Well, shes fixed. thanks fellas

 

Im glad it was something easy!! Just FYI my coolant temps with no reroute and no undertray ( fixing that soon ) are between 88-98C. At the Gap trip even beating the snot out of the car it never got over 98C. I like y0our undertray that you fabbed up Im going to make something similar. Your setup looks really clean. I am also using a Cometic HG. I have 2500 miles on the built motor now without issue.

 

That would definitely cause a problem.

 

Put 140 trouble free miles on it today in 90 degree weather. With AC off she cruises right around 190, AC on she goes up to 205 ish.

 

*Note* When members post about a temperature issue, make sure to ask if they wired the fan in properly.

 

haha yup

 

Dang, I'm jealous. With the old setup I was running (FM setup with ewg, no undertray, koyo rad), I could easily drive around with the AC on unless it was in the 90's in stop and go traffic. Now once I've changed setups, added hood vents and a coolant reroute (still no undertray) my temps start climbing the SECOND I turn on the AC. I hit 220 momentarily before I turn off the AC and it drops back down pretty quickly and settles at like 205.

I know I *should* have an undertray.... but it's blowing my mind that I'm having issues right now that I didn't last year and now I have a hood vents and a coolant reroute and I can't even turn on my AC without the coolant trying to vaporize itself. I'm going to try what someone suggested above and try to burp the coolant again with the heater blasting, but other than that I'm a bit at a loss.

 

Can you sit at idle with AC on without overheating? If not I believe you have an airflow issue.

 

You know the miata doesn't have a heater control valve like other cars, so it doesn't give a **** whether your heater/blower is on or not.

 

Just spitballing, but this seems to make sense to me:

To get airflow across the radiator, there must be a positive pressure differential between the front of the radiator and the back of it. The purpose of the undertray is to keep air from under the car from piling up inside the engine bay and creating a high pressure region behind the radiator, thereby reducing or eliminating said pressure differential.

The purpose of vents (as I understand it, at least) is to take advantage of low pressure regions that occur on the surface of the hood (due to airflow interaction with the hood geometry) in order to draw air out of the engine bay, thereby decreasing the pressure in the engine bay and increasing the pressure differential across the radiator. You want the hood vent to be pulling air from in front of the radiator, through the engine bay, and out the vent.

Without an undertray, however, the vents are just pulling air from under the car instead of through the radiator (path of least resistance), rendering the vents useless. Furthermore, it's very possible that the motion of the airflow from under the car to the vents is creating some high pressure regions behind the radiator, thereby decreasing the pressure differential and inhibiting cooling.

Conclusion: fundamentals are key; it's silly and possibly counterproductive to do fancy stuff like hood vents while ignoring basic, fundamental stuff like an having undertray.

 

I'd thought about that re: vents and it's an easy enough thing to test. I'll tape up my vents and see if that makes a difference. I confirmed that the secondary fan turns on with the AC, so there's that.

 

I think your car needs to be named "Mega Maid."

 

Ride,

He's not saying tape up your hood vents. He's saying add the undertray that keeps Miatas from overheating.

 

Oh I fully understand that. I just figured it was an easy enough thing to test and see if covering up the vents would bring me back to my old baseline or to a better state than that because of the reroute.