Car runs hot after long highway drive

mricci

Member

Aug 17, 2003

301

0

17

Massachusetts

Oct 24, 2005

#1

• Oct 24, 2005

• #1

My car runs cool almost all the time. I only have a stock gauge, but its usually only about 1/4 of the way towards hot. It stays cool while driving, even for long distances. But once i get off the highwayafter driving at least 45 mins, if it sits for more than a few minutes at a light or in traffic it heats up. It hasnt overheated on me yet, but runs up past normal on the stock gauge. Then that causes it to start pinging and running like crap.

 

FlyBy763

Member

Apr 23, 2004

439

0

17

Palm Bay, FL

Oct 24, 2005

#2

• Oct 24, 2005

• #2

Are your cooling fans working?

 

mricci

Member

Aug 17, 2003

301

0

17

Massachusetts

Oct 24, 2005

#3

• Oct 24, 2005

• #3

yea, at about when the gauge gets halfway they are coming on, i can hear it when im sitting in the car. I can start the car up and let it idle for 30 mins and it wont get that hot, or if i drive a shorter distance then let it idle it wont get hot.

 

HISSIN50

"How long does it take to get help in here?

15 Year Member

Nov 29, 1999

31,179

34

129

Oct 24, 2005

#4

• Oct 24, 2005

• #4

Are you saying that you can let the car idle for 30 mins without getting it up to ~210*F (low speed fan comes on there)? How cold is it where you are at (I dont know relative temps back East). I know when it gets real cold out the car runs hottest at idle since it can actually warm up a little - otherwise the cold air rushing over the coil fills the motor with relatively cold coolant as soon as the t-stat opens.

Good luck.

 

mricci

Member

Aug 17, 2003

301

0

17

Massachusetts

Oct 24, 2005

#5

• Oct 24, 2005

• #5

It will get up to temp if i let it idle, but if i let it idle after a long drive on the highway it gets much hotter, than if i let it idle after a drive around town. Im going to get an aftermarket gauge so i can know the exact temps. Its not overheating yet, but getting real close. The temp will climb up to the l on the stock gauge in about 1 min after a highway drive.

 

N

NashSupreme

New Member

Oct 24, 2005

10

0

0

Wentzville, MO

Oct 24, 2005

#6

• Oct 24, 2005

• #6

i have a 94 gt and it does the same thing, i flushed out the radiator system and it helped a lot, but it still does it especially in the summer

 

HISSIN50

"How long does it take to get help in here?

15 Year Member

Nov 29, 1999

31,179

34

129

Oct 24, 2005

#7

• Oct 24, 2005

• #7

That sounds like a plan - the symptoms dont really make any sense unless your fan is not coming on after being on the highway (like a VSS input hiccup). A real gauge should help narrow it down.

Good luck.

 

MLC Stang

Founding Member

Aug 23, 2002

210

0

0

Atlanta, GA

Oct 25, 2005

#8

• Oct 25, 2005

• #8

Guys,

Our cars are notorious for developing a very slow leak on the passenger side of stock radiators, between the radiator core and the radiator end cap down low on that side.

It’s hard to see, and hard to diagnose, since it it’s a very slow leak and the leak mostly drips down onto the cross-member directly under the radiator, burns off, and never makes it to the garage floor.

Until I fixed that, my car had the same mysterious symptoms of a low coolant light every month or so, and overheating when coming off of a long freeway run and getting back into slow city street traffic!

When you are moving at highway speeds the air flow through the radiator is sufficient to keep the temps down. But, when you then slow to side road speeds and stop & go traffic, the system can't keep up.

Have your coolant system pressure checked to see if it has a slow leak. If it does, it's probably at the location I mentioned above, and may be the cause of the overheating you described.

 

mricci

Member

Aug 17, 2003

301

0

17

Massachusetts

Oct 25, 2005

#9

• Oct 25, 2005

• #9

Thanks for all the help, ill get the pressure checked, and flush it out and see what happens.

 

A

aduffany

New Member

Dec 26, 2010

1

0

0

Dec 26, 2010

#10

• Dec 26, 2010

• #10

hhmm

did you ever get the problem fixed, what did it end up being. I have the same problem