[mike8066]

Guys,

I'd like some input, advice, ideas, etc. on keeping a 95 Cobra 5.0 cool in 100+deg heat.

Year round the normal operating temp is between 210-212. I am in Oklahoma and we are into week 8 of 100+ deg weather. Average daily temps are around 105 with 60-70% humidity...IT'S INSANELY HOT! The engine temp has been more around 212 on hiway, and 215 in town, but when I kick on the AC, it levels out at 225-230!! Maybe it's my own paranoia, but that's way too hot for my taste.

I'm running a Mishimoto (yes, I know...but no probs yet. LOL!) dual core 3" aluminum radiator, a Mark VIII electric fan, and a Mr. Gasket 180 thermostat. I have no major mods to the engine, pretty much stock. I've replaced the stock dash temp gauge with an Equus mechanical temp gauge. The oil is changed on a regular basis and there are only about 2000 miles on this motor. With gas prices the way they are, the timing is set to the stock 10* to allow for use of regular grade gas.

I've heard people on this site rave and swear by Water Wetter, saying that they saw major reductions in heat using two bottles with a higher water-to-coolant ratio mixture. So, I flushed my system, put in a 25/75 coolant/water mix and 2 bottles of Water Wetter. It gave me about a 2 degree drop, not much.

I do have a dual scoop hood (Stormin Normin style), and have had a couple of people tell me to block off my scoops because it is throwing off the air flow under the hood. Any truth to this?

Any ideas, or am I just stuck with driving my POS truck during the summer and the Cobra the rest of the year??

Thanks!

[Bullitt95]

I have the same Mishimoto radiator, the same Mr. Gasket 180* t'stat, and for 7 months/year have to put up with 100+*F outside temps., but my engine typically runs at 190-200*F most of the time and will only go up to 210*F driving fast on the highway with the AC on.
It doesn't sound like you have a major problem but there are two things I think you should check. Firstly, make sure the drivebelt tension is correct so that it doesn't slip when you add the extra load of the AC. Secondly, make sure that the lower radiator hose has a spring inside it so that it doesn't collapse when the water pump is pulling more coolant at higher rpm.

[brokenweasel]

I just pulled the A/C radiator thing out of my truck, and it stays noticeably cooler on the gauge since air is coming straight through the radiator with hardly anything in front of it now. Do you have a fan surround? I've heard those help a bunch to pull air through at slower speeds. You can also get a little tool that will straighten the radiator fins which will increase cooling abilities.

Also, you can check the thermostat in boiling water and a thermometer to see where its actually opening.

[mike8066]

I don't want to pull my AC condensor (although that WOULD drop the temp in a major way! Poor design on Ford's part...), because I wanna keep my AC. Yes, the fan has a shroud, which has a good seal all the way around the radiator. The thermostat is working...although last night I noticed it didn't open and drop the temp until about 215*! Questionable for a 180* stat. The radiator has a 19lb cap on it, so in theory, that should set my water's boiling point to about 250*. With that said, it seems safe enough, but topping out at 230* with the AC on just makes me nervous. A 20* difference isn't much room for error.

[91sleeper]

change the t-stat and see what happens. We have had troubles with the mr. gasket stats down here in the south. I stopped selling them due to the complaints.

[95project]

i have a similar issue..same radiator, 160 stat, and twin moshimoto fans...my problem is i dont know which gauge to believe...my new digital gauge reads between 210-225 usually which is too high in my opnion, but my Moates QH shows much lower during datalogs...i have a hard time believing the ECU is wrong, but who knows...

i would try a different thermostat...it should open long before 210....

[mike8066]

OK, so I cleaned out the AC condensor in front of the radiator and had the system pressure tested. The pressure test revealed a pin hole in the upper rad hose. After changing the hose, pressure held good. I decided to swap the 180* stat with a 195*. My luck couldn't be worse! I went through TWO of them that wouldn't open!! Since the stat wouldn't open, it wouldn't allow me to burp the system! The first one was a Murray brand from O'Reilly's and the second was a Stant from Advance Auto. I thought it was strange that 2 stats of 2 brands from 2 places would be bad, so I broke out the pan of water on the stove. The Murray never opened, even after the water was boiling. The Stant did open about 1/16", but not until the water was over 220*! Out of curiosity, I repeated the pan test with my original 180* Mr. Gasket HiPo, and it promptly opened fully at about 190* or so (pan water temp). So, rather than continue buying more 195's, I just put the 180 back in and it allowed me to burp the system. Still haven't fully tested yet. Will let you know after a test drive. I do still plan to go to a 195, but I'm going to order a Ford Motorcraft stock replacement and will try again next week after it arrives.

[Bullitt95]

Originally Posted by mike8066 I do still plan to go to a 195, but I'm going to order a Ford Motorcraft stock replacement and will try again next week after it arrives.

Why bother when your existing t'stat is working fine? Changing it isn't going to help.

[mike8066]

Bullitt, I am starting to agree. The main reason I was thinking about going to the FMC 195 is just to put everything back to stock.

After testing it today with and without AC, nothing has really changed. It does seemed to have dropped a degree or two. It sits around 208-210 w/o AC (212 when sitting), and between 218-220 with AC on.

The one thing I have noticed is that there is no change when getting up to speed, such as the hiway. I would think that would lower it a hair more, but it doesn't. So maybe there is still an airflow issue through the radiator.

Guess, I may just have to deal with it. Hopefully this 106* weather won't last much longer.

[BiggusJimbus]

Good info. Thanks. I sure do get a lot of heat with the AC on.

[Bullitt95]

Originally Posted by mike8066 Guess, I may just have to deal with it. Hopefully this 106* weather won't last much longer.

Like I said, I don't think you have a major issue but check the things I suggested in my first post.

[Beast]

its been hot here in chicago also and I hope u come up with a solution because my stang ran kinda hot the other day I had the ac on. 220. I bought a new thermostat a 180 I just have to have installed.

[furreal302]

My 94 runs pretty warm too. Going up a long hill last night it was approaching the H on the temp gauge. I had to turn the heat on to get it back down. I'm thinking the radiator isn't as effective anymore with 217,000 miles on it.