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Low Coolant Light

01-17-2007, 12:06 PM

I need some help..

97 lumina ls 3.1L engine.
A year or so ago from pepboys I had raidator flushed and thermostat changed and water pump replaced. I have 76k miles on the car. For the past one week or so I have been getting "Low Coolant" light on. It's not on all the time, it comes and goes, especially at the turns. I checked the reservoir, it was almost empty, so added, went top the hot line. I was on the way to work, so quickly added DEX-COOL coolant. I have checked the level today a day later in the reservoir and it is between hot and cool levels, also the llow coolant light is still coming on, intermittently as mentioned earlier. H
ow do I troubleshoot what the problem is?
I am thinking it's the sensor but not sure and where it is located?
temperature guage is not showing hot, the needle location is normal.


01-18-2007, 05:18 AM
You may need to open the bleeder screws and purge some air.

You'll need to open the radiator cap (not the resevoir) and open the bleeder screws and fill into the radiator until you have a solid flow of coolant at the bleeders, then close them up, put the cap back on and take it for a drive and see if the light is gone...

I have the same car, and honestly I didn't even realize it had a low coolant light...never seen it...have no idea where the sensor is...

01-18-2007, 06:52 AM
sensor should be in the side of radiator...


01-18-2007, 09:15 AM
I have the same car - i had the same problem.

Not to burst your bubble but prepare for the worse.
Mine ended up being the lower intake gasket. about an $800 repair (at a shop) Do as described above, and keep your eye on your anti-freeze.

Also - look at the passanger side of the engine - where the intake meets the head. usually you can see "wet marks" where the head meets the intake. if you see evidence of that, i recomend getting a pressure test done to verify any leaks.

I have had to have my lower intake done twice. (once under warranty, 2nd time at my expense).

about 1 month ago I had the unfortunate expense of a head gasket leak. $1100. But that included hot tanking the heads and resurfacing.

Car runs like a champ now. I love my Lumina, and I will hold on to it until it totally blows up.

1997 Lumina, 3.1, 128,000 miles

and yes - sensor is on radiator - about 3" below the filler neck

01-18-2007, 01:14 PM
I would have blown the whistle for a head common:just a hint: If you have ANY irregularities in the performance of the turning cold sporadically or constantly when you expect hot, or definitely not heating as hot as it used too all of a sudden, then no doubt, it is a head gasket...and naturally, you would get intake changed as same time.

01-22-2007, 09:08 AM
I agree with scrapper that if you're actually using coolant, you have the infamous intake gasket failure that all 96-later 3100 will experience. If you use one of the improved design gaskets from Fel-Pro, you'll be good for another 200k+ miles. Unless you've overheated the car or you've been driving it like this for quite some time, I doubt seriously it's a head gasket.

If you're not using coolant, then the coolant level sensor located in the passenger side radiator tank is probably mucked up with dex-cool sludge and needs cleaning or replaement.

01-23-2007, 12:05 AM
just wondering why the 96+ 3100s only are prone to blowing intake gaskets? Aren't the older 3.1's pretty much the same design as the new one? Are the older gaskets made out of metal, or different torque specs? Just wondering.

01-23-2007, 10:32 AM
I have been wondering too where could the whole reserve tank of coolant must have gone! It's not leaving any spots on the driveways or parking spots. I plan to check out the oil this weekend and see if it's contaminated with coolant. I did not do the air bleeding yet, but the low coolant light is not coming on anymore, atleast, it's been 3-4 days. I think the air pocket must have worked itself out which the sensor might have been picking up.

I will post the findings after checking the car on weekend.

Did any one try getting this repaired under manufacture defect from manufacturer?


01-24-2007, 02:29 PM
When GM redesigned/refined the 3100, and switched to the roller rocker arm design, is when the trouble started. The redesigned intake coupled with the rediculously low torque values allowed the bolts to loosen over time due to the different expansion rates of the metals invloved. This allowed the intake to "walk" side to side and eventually cracks the plastic body of the junk OEM gasket at the coolant transfer passage allowing coolant to get in the oil. The newer design metal-rubber laminate gasket and the use of threadlock on all the intake bolts will eliminate this issue. I've done many of these intake jobs, and on almost every one, the end bolts (the 4 short ones) were barely finger tight (some I could remove by hand). The actual issue is a combination of a junk gasket design, and no use of threadlock from the factory to keep the bolts from gradually working their way loose. You will rarely if ever find this issue on a ball and socket rocker arm 3100 or VIN-T 93-older 3.1, even though the basic engine design is the same.

01-25-2007, 03:33 PM
I am back sooner than I thought I would.

Light came on again, so checked the reservoir, empty again, added some. Also, checked the engine block from passenger side and there is trace of coolant where the manifold meets the block. called around few shops, price range $750 to $2750 (one recommended changing the engine), that's lot of money. I know I haven't been running the car hot. constantly been checking temp guide. Did I do any damage to engine!

Here's an interesting aricle I found regarding this problem. I called but was denied.

I have seen "tblake" post some pictures regarding the repairs on his pontiac. Is the process same for lumina too! can some one post instructions on how to perform this job? I am not an expert but I did perform power steering pump replacement on this car. How difficult is the job, what are the do's and dont's? If any one of you is from greater new orleans area , can you a recommend a repair shop, who is economical!

thanks for the help.

01-29-2007, 01:02 PM
On sunday, I thought I will get the work done by professionals, so I went early to PEP-BOYS to get 2 things checked out coolant leak and car's wobbling, at take offs after braking and shimmy at high speed. I walked in at 9.30 AM, the guy said it would be checked in few minutes. At 11.00, I ask what's up with my ticket becuase it is still sitting where I parked while other cars are being pulled in. Anyways, another 20-30 minutes later they tell me radiator hoses are bad and needs to be replaced, cost $175.00. Wobbling problem! they say brake rotors look good but not sure why it is wobbling, duh! so 4 hours later and spending $40.00, I still am not sure if the diagnosis of the coolant leak was correct. I am not really worried about the wobbling right now. I am worried I won't have a ride. Sorry had to vent.
I have decided not to go back to that PEP-BOYS branch, for asking questions, I got attitude from the lady. ON top of it she insisted that I pay for brake inspection and she could not answer my questions regarding wobbling. I was pissed!

If it is hoses, it should leave some trace on the ground or hoses!
How do I proceed from here! I will leave car idling and check for the hose leaks today.

thanks for any suggestions.

02-14-2007, 09:21 AM
I had this same problem on my 95.
the sensor is on the cap side of the radiator and about 3-4 inched down on the end cap.
a little clip lolds the sensor in place.
easy to replace and the part was cheap too as i best remember.

The guys on this forum told me where it was and now i can pas this on to you.
This is a great bunch of guys that really want to help us that dont know as much.....thanks to all.

04-09-2009, 03:57 PM
On my 1999 I replaced the radiator and my light stays on and before I replaced the radiator I had no problem with the light. how do I bleed it? does the engine need to be cold? and where are the bleeder screws?

12-15-2009, 05:45 PM
Just gotta put in my two cents worth:
On my '96, the coolant level sensor is on the lower, left side of the coolant tank, toward the front of the car. Not sure how to get the old one out, if anyone has, let me know, I have a new sensor to put in... :confused:
My bleeder screw (one) is a small bolt lookin' thing that goes straight down into a vertical black tube which serves as a junction between a metal line running across the front of the engine near the valve cover and a short rubber elbow hose that goes to an outlet coming out between the lower intake manifold and the plenum. The tube with the bleeder is just in front of the power steering pump. You don't need to remove the bleeder screw, just loosen it 'til you get a good flow comin' thru it.

12-16-2009, 08:16 PM
My 97 Lumina coolant light has been on for probably 3 yrs. I was thinking of resetting computer to make it go away...don't know if it is bad sensor or more problems.

I have replaced the LIM gasket a while back. Then more recently the water level in bottle started going down again. Then I discovered the radiator seal-at the plastic interface-started leaking. A few years before, the temp. gauge would climb up more than normal. Mechanic I took it too said nothing was wrong. Now, after replacing rad., I think it is finally normal again.

I suspect the head gasket may be about to go, cause bubbles would appear in res. bottle occasionally. But I don't know if the problem was corrected with the new rad. I guess I will see if I take it on a long trip.

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