Radiator Light Keeps Coming On

[SuperCoupe400]

My radiator light ("93 SC4) started coming on a few days ago. It typically lights up once the engine get's close to normal operating temp - but sometimes after less than only two minutes of the engine running. The engine never overheats or even tries to - even after driving 30 minutes home or work. Operating temperature is normal and constant.

I've changed my coolant (plus used a coolant system cleaner - I think it was Prestone Super Flush), installed a new radiator cap (just in case pressure was escaping through the OEM one) and also replaced the thermostat (turns out some of the gasket material in it was a bit warped and corroded anyway).

I thought I was home free after having taken it for a good 40-minute spin that night with no radiator light, but the next day on my way to church the radiator light came back to haunt me.

I was going to do a back-flush, but couldn't quite tell which hose to make the splice into for the flush-kit. But something tells me that not even a back-flush will cure this issue, because the coolant I drained out appeared to be in really good condition.

I figure that clearing the computer codes (disconnecting possitive battery terminal for a few minutes) won't do any good, because the light isn't on from the moment the engine is started - only once it heats up. What could this be? Anybody have any suggestions - besides me getting raped by taking it to the dealer?

thanks.

[Theodore]

that light went on for me too at first i had no clue what it was looked like a house. lol It kept going on and off but now it stopped, but then again may AC is not working to its coldest possibility. So there might be a leaking problem.

If u get any answers or ideas let us know.

[SuperCoupe400]

If u get any answers or ideas let us know.

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Well, since I think i've exhausted just about every remedy, I think my next step will be performing a back-flush. My brother's a certified mechanic, so he should be able to help me find which hose to splice into for the back-flush kit.

Other than that, someone mentioned in a post on a previous radiator topic, that the sensor inside the coolant reservior may be bad. But that replacement will be a last-ditch effort. First I'll see how much that part runs.

[Theodore]

im more worried about other work now, so i left that problem on hold. But im gonna look into the things u did and try them out.

[SuperCoupe400]

Okay. I found the problem. It is the coolant sensor (Level Warning Switch Assembly). I'm pretty sure it's gone bad. I unplugged it (the wire coupling, not taking it out of the resovior) and the light hasn't been back on since.

Someone in an older post about this same problem mentioned possibly cleaning this part. I'm curious to know if that can even be done, seeing as how the part housing the sensor is enclosed in a seamless plastic tube. Not to mention, it seems impossible that anything might even make it's way into the sensor - given that solidified "jello-like" seal is unbroken.

Oh well, guess i'll just fork over the $96 for a new one some time before winter hits. I can't find the part anywhere but the dealer - yet.

[texsn95]

The contacts at the bottom get corroded over time. The coolant completes the circuit between the 2 prongs, so when it drops below sensor level, it can tell, so it trips the low coolant idiot light. Or if they're gunked up, it'll think the same thing. This is how the sensor in the Cobra works, so it's probably a similar setup. Pull it out and clean the contacts, whatever is on there should come off pretty easily.