eb110americana

iTrader: (4)

So I got the cliché low-coolant light on a long trip. Checked it about a half dozen times and the coolant was fine, decieded to just replace the sensor rather than mess with cleaning it and having to deal with the problem again. After replacement, the light went away for about a month.

Now it's back, and it turns on more-and-more frequently. Nearly 100% of the time now. Coolant level in the radiator and the overflow tank are both still fine.

Up until now, I've never seen this light illuminate on my car. I just had a bunch of work done though:

• Shorty headers installed
• New cats
• Intake pulled to replace valley pan gasket (crossover coolant tube remove/replace for access)

I don't know that it matters, but the coolant level sensor I selected is a Standard Motor Products - FLS24T.

So what do you guys think it is?

1. New sensor is defective?
2. Sensor installed incorrectly?
3. Air getting into system from loose crossover tube?
4. Air getting into system from blown head gasket?
5. Wire damage somewhere on new exhaust?
6. Chupacabras?

Thanks in advance for your suggestions.

wssix99

iTrader: (5)

Sometimes it can just be the sensor going bad again. Others have had power steering fluid contamination issues that has done in the sensors.

Do you have a stock P/S cooler on the car?

chrysler kid

iTrader: (14)

Just unplug the sensor the light will turn off

eb110americana

iTrader: (4)

My car is not a true WS6, only a Trans Am, so I'm not sure it has a power steering cooler. The radiator is stock though. I would think PS fluid would float to the top of the coolant and have a noticeable smell, which I did not detect. I'll have another look under the hood soon and try to verify all this. Thanks for the suggestions wssix99.

The sensor is only about a month old. I should also note that I put a new OEM radiator cap on it about 18 months ago.

RPM WS6

iTrader: (3)

If it's a base '98 Trans Am, it did not come with a PS cooler (unless someone special ordered the car with RPO V12, though I'm not even sure if that was allowed to be ordered without RPO WU8, WU6 or WS6.)

Anyway, just check the radiator hose on the driver's side for any sort of metal coupler in the middle of the hose. If it's a solid one-piece rubber hose, then you don't have a PS cooler.

BandDirector Blk98ZM6

iTrader: (21)

My aftermarket sensor didn't last but a few months either...long enough to be out of warranty. I just unplugged it and check my coolant level from time to time. Later F-Bodies eliminated the sensor completely, so if GM thought it was silly, I guess I do too...

wssix99

iTrader: (5)

The sensor is key for an aluminum engine and it saved mine from warping. You don't want to run this engine low on coolant.

I and other members here have seen our water pump seals fail in a way that injects air in to the system, causing the radiator level to dangerously drop. So, the sensor can be pretty important - also for older cars. (Rubber degrades with age and not use.)

RPM WS6

iTrader: (3)

I would tend to agree. It's a nice thing to have, if you can get it to work right. But I wouldn't put a great deal of money or effort into fixing it if a simple sensor swap didn't work, as you're really in no worse shape than those with later model year LS1s which didn't have the sensor to begin with. It wasn't a big deal to manually check the coolant level on my '02, or on any other car I have owned that didn't have a coolant level sensor.

eb110americana

iTrader: (4)

Thank you, this is what I was looking for. I got mine from RockAuto, they're usually pretty cool, so hopefully I can get another. Probably just go OEM this time.

I don't fault anyone for not having theirs plugged in if that works for you, but I personally like the extra safe guard built in. At least the sensors are not that expensive, and the first one lasted probably 16 years.

BandDirector Blk98ZM6, did you get another sensor and does the system now work as intended? I'll try to report back as to my success or failure when I do this, but if the thread goes dead, just post or PM me to follow up.

99Bluz28

iTrader: (35)

#6, Micro Chupacabras built-up on the sensor causing the false reading.

The sensors are fairly sensitive to any build-up on them(I doubt it's bad). If you're due for a coolant system flush then remove the sensor and clean it and you'll probably be good for at least 1 month. Otherwise drain the coolant down below the level of the sensor, and remove the sensor and clean it, then you be good for at least 1-2 weeks. I didn't have any issues with the coolant level sensor until I had the car 5-6 yrs then it's been a on going issue ever since. Finally about 1 year ago I unplugged the sensor since I was already used to looking at the coolant temp gauge on a regular basis since I couldn't trust the low coolant light for the correct info. FYI, 2001 was the last year they had the coolant level sensor in the LS1 Camaro or Firebird.

99'CajunFirehawk157

iTrader: (57)

U can find o/e sensors (GM 10096163) on eBay pretty cheap, I just picked up one for under $20 shipped.

BandDirector Blk98ZM6

iTrader: (21)

Right now, I'm just running with the sensor unplugged. When the stock one went out, I cleaned it and got another week or 2 out of it. I Then replaced it with an BWD brand sensor from O'Reilly and when it failed, I cleaned it and that didn't fix it at all. Keep in mind every time you replace or clean the sensor, you've got to drain the coolant slightly and then replace, so after doing this 3 times to try and fix the problem, I'm just done with it. It's unplugged, I have no light, and I just check my coolant level from time to time.

Like I said, GM removed the sensor completely in the later F-Bodies, so if they didn't think it was necessary any more, I'm fine with mine being unplugged.

wssix99

iTrader: (5)

I don't think that this is the best conclusion - that because the sensor was removed in 2002, it wasn't "needed." Auto companies have been the world's most talented penny pinchers for decades and they would not have added an unneeded sensor in the earlier years.

I think it is more reasonable that the sensor was removed in 2002 due to other changes made on the car. (Removal of the EGR system, the head gasket change, etc.)

eb110americana

iTrader: (4)

Swapped the (relatively) new aftermarket sensor for an OEM AC Delco part last weekend. While running the engine with the radiator cap off to accelerate the bleeding process, I did not see the sensor light up. However, I let the engine idle once I closed the cap to get it nice and hot. It did turn on then, but I suspect that was simply the last of the air leaving the system.

Checked it cold the next day, and the radiator is full. In the week since, I've driven the car every day and gotten the engine fairly hot a couple of times yet the light has not come back on. I'll hold off final judgment until I take a long road trip sometime in the future and can see how prolonged heat affects the sensor, but at least for now, all signs seem to point to #1: the new sensor was bad.

99Bluz28

iTrader: (35)

This probably won't apply to most of us, but a lot of people don't pay much attention to their instrument cluster gauges. Idiot lights on the other hand seem to catch a persons attention a lot better! IMO, if you perform regular maintenance on you vehicle and check you gauges periodically as you drive a low coolant light isn't needed at all. IMO, Idiot lights are for the masses that typically never even open the hood of their vehicle, so when the light comes on they take it directly repair shop. I'm not saying all the trouble lights are useless, but in my opinion the low coolant is, especially when it's prone to giving false readings.

wssix99

iTrader: (5)

How often should I pop my hood to check the radiator level to protect myself against a low coolant condition? Every day? Every week?


The light is fine, it's the sensor that goes bad. Instead of calling it a false reading, I'd call it failing "on" - which is probably better than failing "off."

99Bluz28

iTrader: (35)

wssix99 Yes, it's the sensor that fails, but it also can give a false reading from build-up on it, the actual low coolant light is not the problem.
Thanks for the correction!

How often should I pop my hood to check the radiator level to protect myself against a low coolant condition?

That's for you to decide, use some common sense. Do what you think everyone that drives a LS1 2002 Camaro or Firebird does without having any coolant level sensor.


My guess, (which is as good as yours) is that the sensors were problematic(failure, false readings) and since the engine temperature gauge would also easily show a coolant system problem(low coolant level) with abnormal temperature readings the easiest/cost effective solution was to eliminate it.