mystery overheating

[leggomieggo10]

i recently picked up a cheap 92 sl that needed a 60, timing jumped 3 teeth, no damage.
did my 60 k, car runs beautiful. but its overheating if i drive on the interstate for about 5-10 min. itll drive all day long through the town an wont overheat. but as soon as i start on the interstate about 5-10 min later the temp starts creeping up. turning on the heat doesnt help at all. its got a new water pump, tstat an fresh coolant, new rad cap as well. my fans are wired so i know there on for a fact. why would my car overheat after driving on the interstate?? if it was a clogged radiator it would be overheating no matter what.

is the trans temp hooked to same gauge???

[Alex3000gt]

Are the fans pulling, or is polarity switched and they are pushing?

Warm up the car, keel it running and pop the hood. Use a piece of paper to see if the fan is truly pulling.

Do both fans come on?

[x2xtreme360]

if it was a clogged radiator it would be overheating no matter what.

Not necessarily. A semi-clogged radiator can definitely cause your issue.

Headgasket.

Steve

Did he say anything remotely close in his post that pointed to a head gasket problem? Why are you still here?

[$$$PIT]

I had the same problem. Turned out I had a leak on one of the O-rings goin' from the water pump to the water neck. It would only leak when I was on the highway. I could drive in town forever. In fact, I drove for 300 miles in town before I took it out on the highway and found the leak the hard way.

[leggomieggo10]

im not losing fluid at all,

its not the the headgasket, ive got good compression an again im not loosing oil, def no oil coolant mix.

an i replaced the oring on the coolant pipe.

so a slightly clogged radiator would cause that problem, weird.

anybody know if the trans is hooked to that temp, its a automatic. i hope my trans isnt overheating

[speedy25]

An AGED radiator is more probably the cause. As they get older the fins detach making heat transfer less efficient. When I got my car it would creep up when I used the AC. When I finally pulled the rad most of the bottom fins were rotted off.

Another overlooked cooling problem is NOT doing a flush after replacing a bad head gasket. Oil in the cooling system will keep heat transfer from happening.

-SP

[leggomieggo10]

i never changed the headgasket, there was never a coolant mixture, im pulling th radiator tmw, i just have a feeling thats not the problem, ive just never seen a rad cause problems only at high speeds after minutes of driving.

how would one check the radiator?? just stick a water hose in it an see how well the flow is
???

[leggomieggo10]

update!!!

alex, i checked the fans they both come on as for the direction they both shpin towards the drivers side, can any confirm this to be correct??

an i pulled the radiator, stuck a water hose in the top an at first it came out a little slow but it may have just taken time to get through the rad, after just a few seconds it came out the bottom in a real nice clear water flow. I than put everything back together an started the car, ran it until it got normal temp, adding water as it got low. im pretty sure the water pump is good, it is new an the water was doing a swirling effect,, once the car got to normal temp the water in the fill neck when down, Im assuming the tstat opened up alowing water to flow. I made a video if it helps, take a look an tell me your thoughts.

when the car got to normal temp the bottom hose was damn hot, like i could only touch it for a a split second before it hurt, but the top hose i could hold my hand on it an it was just kinda warm. Is that normal??

help lol. thanks guys

heres the vid

[leggomieggo10]

alright now im getting pissed off. after all that work, its still overheating, both hoses are hot as hell after driving on the highway,

this is rediculous,i need to know that since it being an automatic, if the trans temp is also on the same gauge, i have a feeling the trans is getting hot

[BaadVR4]

Since the trans fluid is cooled by the engine coolant, any rise in engine temp will cause a rise in trans fluid temp. whether the trans is getting too hot depends on how much the engine is overheating and how long it remains overheated.