347 RUNNING HOT

If this is the fan setup you have, https://www.americanmuscle.com/mishimoto-dualfan-7993.html#customer_reviews go look at the 1 star reviews and read them. "does not keep my car cool" "

"Don't buy.....
Over all, nice look and fit. They just don't get the job done. The cfm's are not enough. My car constantly runs hot....."

"
11990 Mustang - RZ
Installation Time: Less than 1 Hour

Not enough CFM

Ordered this for my fox gt40 heads, cobra intake 130 alt nothing to much daily driver. Set up looks good but could not keep up, ran hot smh not wroth it check cfm rating before buying.

ETC. ETC!!!

I'm late to the party but will through my 2 cents at it.

Recap as I read it and my thoughts:
- Your car runs 190 deg at idle no problems or concerns - I assume this is temp taken from Holley X. If so, this would be engine temp, not coolant temp. What is temp at discharge side of rad? I also assume at idle the fans do turn on.

- Trans cooling line goes to rad and then aux trans cooler - I agree with others, skip the rad unless you need cold weather warming of trans fluid.

- Lower rad hose with no spring - my Fox does not have the spring either, it would be needed if you have collapse. I would get the car up to temp at idle, then rev it up (2000-3000 rpm and hold) and observe the lower hose to see if it collapses. That should answer if you need a spring inside.

- Timing at 10 deg is fine

- Coolant burping - I have always burped the same way and never had an issue.

- You have had this cooling issue with both stock rad/fan shroud and aftermarket fan/shroud and therefore do not believe it is the problem - this seems logical but consider this, if your stock fan clutch was failing and that was the reason for the issue at first, you may still have a shroud flow issue now. Here is why I think this way. My current setup is a 3 core OEM brass style rad with Contour fans and a 180 deg T-stat. If I drive at highway speed on a 70 deg day my temp gauge will read around 180 the whole time. Your system running up to 220 on the highway on a similar day makes me think you are not getting proper air flow through the rad/shroud/condensor/aux cooler. My fans (low speed set for 205, high speed at 215) will NEVER come on when moving on a 70 deg day. On a hot day, my temp will hover around 195-205 (my estimate on the factory gauge) because my fans still don't come on when moving at highway speed (they will come on in traffic and slower speeds)

My fan controller temp sender is in my lower rad hose, not on the engine. Why. Because you want your fans to cool the coolant in the rad, not cool the engine, and really the only place to measure coolant temp leaving the rad (after the rad has done its job) is on driver side tank or lower rad hose. If your Holley is only getting a signal from the sender in the heater core tube, you are getting engine temp, not coolant temp going into your engine. In my opinion, this is not where you should be controlling fans from.

Here is a thread I did on installing Contour fans, but the stand alone control can be applied to any dual fan set up, even to run PWM fans in a non PWM two speed mode.


To test the air flow through the shroud issue, remove the shroud, rehang the fans (even temporarily for a quick jaunt down the highway to test) and go for a drive on the highway. You indicated above that temps on a 70 deg day got up to 220. What happens during this test? The fans are there for back up to get home, but the real test is will temps stay around or under 200 on the highway without the shroud restriction. This will point to shroud or not and really only costs some time.

Good luck and keep us in the loop.