overheating again

[vent69]

my 94 runs about 200-230 on th highway i dont know alot about cars but i know something is wrong. i checked the coolent and its fine any other ideas

thanx alot buddies

vent

[Trance_LT4]

200-230 sounds like what stock vettes run. My 96 ran that way till I reprogrammed the fans to come on sonner (160 primary, 193 secondary) and removed my thermostat.

[Edmond]

That sounds awfully high for the highway. Since you've always got air coming in underneath, it shouldn't reach that high of a temperature. Those are easily reached in city driving but not highway driving.

[Trance_LT4]

6th gear was always my hottest one. I'd downshift into 5th when the temps got to 220, and they would go back to 205-210

[vette-dude]

My 94 was doing that too but once I cleaned out the junk that was blocking the rad and AC cond. it now runs about 198 on highway and at the most 205 around town. Suggest you look in the slot on shroud on pass side of car and see if there are leaves and debris in there. Look at previous posts on this subject as there is alot of other things that may cause the problem also.

[CELT4RAGTOP]

Vent,

Like Vette-Dude suggested, I would do a search of earlier threads on "overheating" There are at least two or three (one is mine) on the subject and the causes include bad thermostat, bad water pump and clogged radiator (both inside the radiator and outside).

I will leave the specific recommendations to the generous people here on the CAC that know a world more than me, but I do have a question. When you say your are overheating are you really overheating (i.e. the engine light comes on and you have to pull over) or are you just running hot. Like Edmond said 230 is too hot if you are traveling at highway speeds, but I do get to 230 sometimes when I'm sitting in stop and go traffic.

This is what I've picked up from reading the other posts. Take if for what its worth and hopefully someone else that actually knows what they are talking about will help out.

If you are just running hot, then you should check the exterior of your radiator. Someone posted some pics and you would be amazed at the stuff that gets sucked up in there...leaves, sticks, plastic bags.

If you are overheating (i.e. gotta pull over cause you're over 260) then you may need to check your thermostat or your water pump.

[c4ever]

A few items to check

Flush cooling system
Shroud and spoiler all in place.
Fans turning on properly.
stat funtioning ok
Debris in front of radiator(already mentioned)
Hoses aren't collapsing?

At highway speed down here(80+), I run at 175 degrees with A/C on with an ambient of over 90. In traffic with A/C about 200-210.

I run a 160 stat with stage II chip and 70/30 anti-freeze mixture.
Lower anti-freeze mixture made a huge difference.

Hope it helps.
Carlo

[chevyaddict]

All these suggestionsd sound good - another couple things to try is to by-pass the coolant switch and ground the wire - this makes the primary fan come on all the time. This is only a good idea if you are in a warm climate.

Also, part supply stores sell this product called 40 below. It is an additive that you use without anti-freeze and it works! Our 84 C4 runs at 170 - 190 now in the city - and with the AC doesn't get above 200 even at an idle. Of course, had to completely flush the radiator and clean all the debris out too.........