badazz68stang

I was jus wondering how hot a 289 should run at idle speed? I just got out there and hooked up a new gauge pod and when i got rid of the old idiot light and installed the new temp. sending unit my gauges eventually showed readings of upwards of 220 degrees, im almost positive that this is way too hott, so i immediately shut off the motor, any suggestions?

Dan66

Yep, that's way too hot alright. Plenty of things to do though: a complete backflush; a 160Ëš thermostat; a recovery tank; new 4 row radiator (with new cap); and a tight-fitting fan shroud usually do the trick. You can try each of these things one at a time and sometimes find your culprit; but at nearly 40 years old, odds are everything should be replaced anyway.

badazz68stang

well, right now i dont have the fan shroud on, but that alone probably wouldnt cause it to heat up that much would it?

Cannonball888

Yes it would. And when you get a shroud make sure the fan is spaced so the blades are half way in it and half out. personally, I'd get a 3.5" shroud and a shorter spacer.

Dan66

3.5" shrouds are often too deep. You want the fan to be as close to the radiator as possible; but then have only the front half of it within the shroud. I am using one of the 3.5" fiberglass shrouds trimmed down to just where I want it. Also, make sure you get a good seal against the radiator. Fill all the gaps with strips of foam insulation. That way, no air can be pulled from around the edges of the shroud. It all has to be sucked through the radiator. I can't stress how much of a difference this makes.

Soaring

I agree about the shroud making a huge difference. I didn't put any insulation around the outsides, and mine still made a big difference. After a back flush and larger radiator, the shroud would be the next thing to add, then a recovery tank. Here is some information I have in the FAQ section. Take a read.....
http://www.arrowheadradiator.com/14_...utomobiles.htm

6mustang6

I thought the engine runs hotter at idle??? when it's moving, it'll go down 15-20 degrees.

Clu7ch

yeah, when you are sitting there at a light or in beach traffic (gotta love the jersey shore!) there is no where for the hot air to go really so it just kinda sits there. it doesn't mean you're gonna run hotter or not, but you will have a build up of heat. also, when driving there will be a slight increase of air flow thru the radiator.

coop67

I have a '67 with a newly rebuilt 302 roller (.030 over) with a holly 4 barrel. There's a 4 row radiator and the fan shroud is in place. It's still running SUPER hot.

See here:
http://coopgrafik.com/blog/?p=27

Will an aluminium radiator really help? Do you think I should go with an electric fan? Any recommendations on brands? I kinda thought everything was right but it's not helping at all. It's 100+ where I live and drive to work every day. Money isn't an issue so overkill solutions are welcome.

Thanks,

Coop

Soaring

If money is not an issue, then get a Griffin aluminum radiator, an electric fan, and an overflow tank. Make sure your block has been flush thoroughly before you put the Griffin on. Also, check to see that you have a 180 degree rad cap that is sealing well.