Heating up at highway speed more than in traffic...230+?

[todd92ford]

Instead of replacing everything, hoping someone can point me in the right direction.


92 vert auto. It IS 110+ during the day here this week, so I know shes gonna run a bit warm. But its at what I figure is 230+. Im running at the O in NORMAL. I changed out the stat yesterday for a Mr Gasket 180, did a bottle of watter wetter, a gallon of 50/50 and a gallon of distilled water. burped it out and watched it climb in the driveway. Opened perfectly right near 180. Around town its running around 200, but when I hit the highway at cruising speeds it starts to climb to what I figure is 230+ at and above the O. Today, it got to the last line before the red at which point I got off the highway and turned on the heat and it dropped back to O.

Whats next? Water pump? Radiator? The air foils/deflectors are all in good shape and in place.

Also, when changing the stat I noticed that the bottom of the overflow tank (with the sensor) was kinda whitish. Almost thought "milky". As the stock stat dried out, its now whitish too. Do I have anything to worry about because of that?

 

[281pony]

milky is when the oil and water mix. blown head gasket... seems to fit the bill if you have been running it that hot.

check your oil, pull the dipstick and see if the oil is clean. look inside the radiator too.

 

[2000xp8]

There is almost always some old milky crap in an old cooling system, most of the time a blown head gasket will be a pretty big mess.

If the water pump doesn't leak and the system holds pressure, you probably just need a new radiator.
What kind is it? How old? How thick?

 

[todd92ford]

milky is when the oil and water mix. blown head gasket... seems to fit the bill if you have been running it that hot.

check your oil, pull the dipstick and see if the oil is clean. look inside the radiator too.

when I drained the coolant, it didnt show any milkyness. the oil is also clean.

 

[281pony]

when I drained the coolant, it didnt show any milkyness. the oil is also clean.

ok, then i agree with xp. seems like its your radiator..

 

[4rdnut]

you can't rely on the stock temp gauge, so you have no clue what the temps really are, so get yourself a mechanical temp gauge first so you will know the real temps.

 

[alscobra1]

I would start with a new radiator. Possibly an aftermarket bigger one. It's an auto so trans temps may be playing a role in it. Do you have a pulley kit? Smaller crank pulley will spin the water pump slower too.

 

[GDTrumbo]

Check the lower area of the radiator and condenser for debris in the fins before replacing it.

GT

 

[Onefine88]

Do you still have the lower air deflector installed? Without that a car will typically run hotter at highway speeds.

OOOPS! I now see in you post that you do have it.

My bad

 

[todd92ford]

last night I blew it out with compressed air, and a hose. got a bit of gunk out but not much. very few bent fins, and very clean to the eye on both sides. gonna swap rads this wkd.

 

[89stang1]

last night I blew it out with compressed air, and a hose. got a bit of gunk out but not much. very few bent fins, and very clean to the eye on both sides. gonna swap rads this wkd.

good idea new rad i would put a aftermarket temp gauge in too autometers are nice. I didnt notice you say if car overheated at 230 degrees because at 230 when you shut car off it would be pissing and bubbling in the overflow and hissing?

 

[2000xp8]

last night I blew it out with compressed air, and a hose. got a bit of gunk out but not much. very few bent fins, and very clean to the eye on both sides. gonna swap rads this wkd.

The only way to really clean out a radiator is to take it to a place to be done.
Do i know how they do it? No, but i know it works.
But it's a service really left best for expensive radiators, for example ford heavy duty trucks use radiators that are a grand, so $75-$100 to clean it is worth it, on a car you can get a decent radiator for $150-$200 it would make no sense.

 

[todd92ford]

installed a griffin 3 row and all is well! well below the halfway mark on the guage. thx guys

 

[89stang1]

installed a griffin 3 row and all is well! well below the halfway mark on the guage. thx guys

good deal!

 

[alscobra1]

Glad you got it taken care of man.

 

[Truckie]

Glad it is fixed but that made me think...

do these water pumps have the metal blades or the plastic ones? ( I have not had to replace mine yet) I had a ford overheating and it was the water pump plastic blades worn away. no leaks or any sign water pump was having an issue. just started running hott.

 

[lxman]

I replaced my water pump about a 2 months ago an it was metal blades.

 

[kaitan]

So I am having a similar problem on my '91 vert. Reads at the N of normal, but I had a guy at a shop use a temperature gun and he read 170. Drove from OR to CO, and while the needle did drift toward the last line, it has never hissed or bubbled. Don't really want to ruin the stock dash look with more gauges. Any way to fix the stock gauge? Did replace thermostat and sending unit.