Anyone elses car run hotter on the freeway?

[WhiteDevil]

I just always wonder its always done this even with my stock bottom end but i will usually be aroud 180-190 during city driving but when im on the freeway its more like 190-200. Right when i get off and go back to regular driving it goes back to normal. I would think will all the air flowing over the radiator on the freeway it would be nice and cool. Anyone?

 

[Killercanary]

I ran into this when I put the Xenon bumper cover on my car. It never overheated, but it definitely ran hotter on the highway than it did at idle or on the local streets. It definitely had to do with airflow over the rad.

 

[The Green GT]

I run at like 210 city and HWY, but at like 230 in the city when I come off the HWY. I know theres something wrong with that.

 

[HISSIN50]

Paul's point is right on. Is the little air dam in place under the front end? It helps direct airflow up to the front of the coil as well as creating a low pressure zone behind the coil (both to help air pass through the radiator).

Otherwise, a borderline cooling system can do alright at idle (with the fan supplying a pretty fair amount of air flow, but the engine isnt creating a ton of heat while unstressed). Once under load (at speed), the system simply cannot reject enough heat and becomes overwhelmed.

With that purty combo and living in San Diego, I might assume you have an upgraded radiator? If not, it might be a wise idea. Your temps are like mine (it's 85* today) and we need to go overboard with cooling systems.

Good luck.

 

[WhiteDevil]

Paul's point is right on. Is the little air dam in place under the front end? It helps direct airflow up to the front of the coil as well as creating a low pressure zone behind the coil (both to help air pass through the radiator).

Otherwise, a borderline cooling system can do alright at idle (with the fan supplying a pretty fair amount of air flow, but the engine isnt creating a ton of heat while unstressed). Once under load (at speed), the system simply cannot reject enough heat and becomes overwhelmed.

With that purty combo and living in San Diego, I might assume you have an upgraded radiator? If not, it might be a wise idea. Your temps are like mine (it's 85* today) and we need to go overboard with cooling systems.

Good luck.

Yeah well my cooling system consists of a Fluidyne, twEECer programmed fans, FRPP High Volume water pump, 180 stat, a 60/40 mix of water/coolant and a bottle of water wetter. You would think this would not have any problem cooling my combo. I know my freakin fluidyne is leaking pretty good from the middle of the core and i wonder if that has anything to do with it, or my 180 stat is about three years old and maybe thats acting up . Its not like its WAYY too hot or anything but i would just like it to be more consistant.

The air foil under the bumper is there but i also have a Mach 1 chin spoiler im sure that probably undermines the air foils which are right behind the the chin spoiler.

 

[fordtech28]

Yeah well my cooling system consists of a Fluidyne, twEECer programmed fans, FRPP High Volume water pump, 180 stat, a 60/40 mix of water/coolant and a bottle of water wetter. You would think this would not have any problem cooling my combo. I know my freakin fluidyne is leaking pretty good from the middle of the core and i wonder if that has anything to do with it, or my 180 stat is about three years old and maybe thats acting up . Its not like its WAYY too hot or anything but i would just like it to be more consistant.

The air foil under the bumper is there but i also have a Mach 1 chin spoiler im sure that probably undermines the air foils which are right behind the the chin spoiler.

I had this problem too and I live in Riverside my fluidyne started to leak a little and the car ran a little hot on the freeway I poured in a liquid stop leak by a company named bar they sell it at autozone it fixed my leak and the car ran a little cooler but it also has to do with the airflow on the radiator.I would change out the thermostat put in a mr gasket 180 thermostat keeps my cobra cool between 180 -195 with the A/C on but sometimes it would climb up to 200 when my A/C condenser was partially blocked so check that as well

 

[Grn92LX]

If not, it might be a wise idea. Your temps are like mine (it's 85* today) and we need to go overboard with cooling systems.

Good luck.

Damn I was scraping ice off my windows this morning before leaving for work!!!

Mine used to run hot on the highway, ended up being the radiator. I guess it was dirty or clogged. It was a 3 core pep boys unit. Good thing the 3 core pep boys units are lifetime warranty

 

[blksn955.o]

a hole in the rad. will bleed off pres. making the coolant not as effective, as it works off a combo of press., fluid, air movement over the fins. I would get that fixed asap.


What are you fans settings at? and have you logged the voltage of the ECT? I had a ECT go out and it made my fans turn on and off (more like not turn on at all). Honestly, though...if your overheating on the hwy though the fans should have little effect.

 

[HISSIN50]

You have a very nice cooling set-up.

I agree about the leak. Each PSI in the system raises the effective boiling point ~3*F. 16 PSI rad cap = ~50*F. That's right in the sweet spot too (when considering the BP of even your 60/40 mix).

I also would postulate, as you did, that the Mach chin spoiler runs interferance for the OEM air dam, but I can't say anything about it since I'm too poor to own a Mach 1 lip.

I once fabbed up an old school Mach 1-ish front air dam (a curb dragger that jetted forward with an aggressive rake). I couldnt make it look right with the round GT front corners so I ditched it. It would have been very effective however.

I'd put a cooling system pressure gauge on the radiator and see how long it holds 16 PSIG. If it bleeds off immediately, I'd fix the rad as a possible cure. If pressure doesnt bleed off immediately, I would not hold my breath. When the pump is churning, there wouldnt be much pressure drop.

Good luck bud.

Mike - I grew up in Alaska and moved to the desert for a reason. People from here complain about the heat but if they haven't lived in the cold, they don't get it. I'd rather be hot than cold.

 

[WhiteDevil]

a hole in the rad. will bleed off pres. making the coolant not as effective, as it works off a combo of press., fluid, air movement over the fins. I would get that fixed asap.


What are you fans settings at? and have you logged the voltage of the ECT? I had a ECT go out and it made my fans turn on and off (more like not turn on at all). Honestly, though...if your overheating on the hwy though the fans should have little effect.

Well mine is definately not overheating just running a litttle warmer. I have logged my ECT and it is pretty much right in line with what my Autometer says give or take a few degrees. Fans dont come on over a certain MPH also.

Damn I was scraping ice off my windows this morning before leaving for work!!!

YIKES i think here in san diego it was in the mid to high 80s too bad i was couped up in my office from 10-6pm

I had this problem too and I live in Riverside my fluidyne started to leak a little and the car ran a little hot on the freeway I poured in a liquid stop leak by a company named bar they sell it at autozone it fixed my leak and the car ran a little cooler but it also has to do with the airflow on the radiator.I would change out the thermostat put in a mr gasket 180 thermostat keeps my cobra cool between 180 -195 with the A/C on but sometimes it would climb up to 200 when my A/C condenser was partially blocked so check that as well

I may change the thermo soon. Is it ok to run the aluminum radiator stop leak with aluminum heads? Its not going to coagulate in my head water passages or something?

 

[LoudToy958]

Whats up there JP. Nice to see the car is running. If its just running a bit warmer, that could be normal. My Cobra does the same thing. I know you have aftermarket temp gauge, but those of you that don't would not notice.

I have noticed that my oil temp is about 210* on the freeway, and drops to about 180* - 195ish* in the city(under conservative driving conditions). I have done a lot of reading on this subject to determine if I needed to cool the oil down, but it appers this is quite normal. Not sure if this is any help, but there is a chance it could explain a 10* or more change in you coolant temps.

With the temps you are seeing, I don't know that I would worry too much. Especially in San Diego. I would still look into the radiator leak issue as JT suggested though. That is just something that should not leak....

Catch up to ya soon, Shane

 

[bmac50]

I had the same problem with the running a bit hotter on the road vs town driving. Ten bucks and ten minutes solved the problem with installing a 180 thermostat. I went for overkill and installed a transmission and oil coolers in front of the radiator and water wetter. Being in Florida heat is a bit time killer.

 

[WhiteDevil]

Whats up there JP. Nice to see the car is running. If its just running a bit warmer, that could be normal. My Cobra does the same thing. I know you have aftermarket temp gauge, but those of you that don't would not notice.

I have noticed that my oil temp is about 210* on the freeway, and drops to about 180* - 195ish* in the city(under conservative driving conditions). I have done a lot of reading on this subject to determine if I needed to cool the oil down, but it appers this is quite normal. Not sure if this is any help, but there is a chance it could explain a 10* or more change in you coolant temps.

With the temps you are seeing, I don't know that I would worry too much. Especially in San Diego. I would still look into the radiator leak issue as JT suggested though. That is just something that should not leak....

Catch up to ya soon, Shane

Hey Shane! Been a while bud, hows ur car running? Thats good to see that its not completely out of whack. I may try the stop leak on the fluidyne first and then if that doesnt fix it i will look into another Fluidyne or a Griffin radiator. And maybe a new 180 thermostat. It might just be more noticable because it has been freakin 85-90 degrees for the past two days.

So anyone have any insight if its ok to use aluminum radiator stop leak with aluminum heads???

 

[WhiteDevil]

ttt what do u guys think about the stop leak?

 

[HISSIN50]

I wouldn't touch the stuff personally. If there's an issue, remove the radiator and have a shop fix it. If your radiator is brazed (no epoxy), it should be easier (epoxy starts to soften around 400*F IIRC). *I think* a shop can still work with an epoxy radiator though - they just have to be real careful/slow.

If you do use a stopleak product, make certain that there is no air in the system. I just do not like that kind of products (but we do what we gotta do, right).

Good luck.

 

[blksn955.o]

I second the get it fixed over getting the stop leak. It will be questionable as to if it does fix it...and if it does for how long??? Pluss if it does not work or does fail you have that crap in your system.

Last summer when I took out the car and got on it in 90 and above temps the guage and log didnt go past 194-196*...this was with a 180 stat though but a stock rad.

 

[WhiteDevil]

People can fix aluminum radiators?

 

[blksn955.o]

yep, ask though if they will repair the tubes or just crimp them if there is a problem with that tube part.

My father-in-law is a snap-on franchisee and has a old bluebird bus as a tool truck. His rad. had been giving him some issues and the shop crimped the tubes that were leaking. He ended up getting a new rad. as too many tubes had been crimped over the years. That was a friggan bus though

The same shop that he went to also can repair tanks and tubes but I think his was just too far gone to try and fix so they crimped.

 

[Pokageek]

I used to have these issues.

#1 I installed a new coolant sensor forget which one but we have 2.
#2 Had my tuner program the fans LOWER.
#3 Installed a 190* thermostat I think it was..been a while.
#4 New radiator.
#5 New fan.

Now it NEVER goes anymore than 1/4 up the guage no matter what. Pretty nice.

 

[Pokageek]

I used to have these issues.

#1 I installed a new coolant sensor forget which one but we have 2.
#2 Had my tuner program the fans LOWER.
#3 Installed a 190* thermostat I think it was..been a while.
#4 New radiator.
#5 New fan.

Now it NEVER goes anymore than 1/4 up the guage no matter what. Pretty nice.