Michael.parker1

I’ve got a 94 lt1 and it overheats while sitting at stoplights or just idling, I’ve got a 160 thermostat in it and a brand new water pump and the coolant has been fully flushed. At stoplights it’s gotten as high as 236 on me, without running into any sort of traffic it will sit around 180 while cruising but as soon as I hit a light or just let it idle it will go up. I can hear both fans kick on right around 226-230ish and they help when it’s just idling to bring it back down to 220ish but at stoplights while I’m driving it doesn’t seem to help as much. I’ve seen the kits online to kick the fan on around 185 instead so I’m considering getting one to see if it’ll help any. Has anyone experienced a similar issue or have a good idea for a fix?

RicardoG

Has your PCM tune been modified?
In stock form the fans are set from the factory to turn on at 219F (primary) and 228 (secondary).
So, while idling at a stop light the temperature can go as high as 228-230 easily.
Easiest way to lower your coolant temp is by reprogramming the PCM if you already have a 160 deg thermostat.

Michael.parker1

I have not had it modified, I heard even with tuning it lower there’s only a certain limit that they can be turned down to I can’t remember the exact temp I had read though

RicardoG

You can set them to turn on as low as you want.
I have mine set up to turn the primary fan on at 200 deg and the secondary at 209 with a 160 deg thermostat .
Hysteresis set at 8 degrees.

DGXR

Read this: Corvettes, Summer, and High Coolant Temperatures
Your car sounds normal to me. The thermostat only determines the temperature when coolant begins to flow -- when it's open, it's open, and it has no ability to increase the circulation of coolant. The cooling capacity of the cooling system is determined by the size and efficiency (rows) of the radiator, the water pump speed, and (most important) the airflow across the radiator. So when you are at low speeds or stopped (little airflow), the temps will naturally climb. The LT1 is programmed to kick on the cooling fans at 228F (low speed) and 235F (high speed). These temperatures are higher than "normal" but it's just how the car is designed -- the higher temps help efficiency and lower emissions.
You can tweak the computer to trigger fans at lower temps, many people have done this with success. I don't care for the high temps either so I just turn on the AC whenever the temp hits 222F, this forces the cooling fans on and brings down the temps quickly (for me too, LOL). Once in a while I will let it get up to trigger temp 228F just to be sure everything is working properly.
I say don't worry about it too much. But if you see 240F, then you can start worrying.

Mr. Peabody

I agree with DGXR your LT1 sounds like it is performing as it should

MarkyMark.

I had this problem on my 94 coupe.....It's a simple fix. The OEM single core radiator did not provide sufficient heat exchange. Not to mentioned is is old and most likely having some restrictions. I bought a new one straight from DeWitt.....a double core upgraded radiator. Cost of radiator in 2012 was $535.00. Drops right in with a slight modification to the radiator shroud. Problem gone. Good luck.

Michael.parker1

this was the option i was hoping not to hear... i was thinking in the back of my mind that it could be partially because of radiator but it seems the only ones worth buying that will fix the issue are 4-600$ which is just more money i was hoping to use on upgrading other parts of the car, im probably going to try and tune it to kick on fans earlier and if that doesn't help much ill probably get a new rad. thanks

MarkyMark.

Running at elevated operating temperatures is not good for the engine....$400-$600 for a radiator. What does it cost to replace an engine?