I have a 2002 Chevy Silverado. The LOW COOLANT light came on. I checked the coolant level in the surge tank. It was less than a 1/2 inch below the cold level so I added some of the DEX coolant. the light is still coming on. Any thoughts on what else it could be? There is no direct access to the radiator and I don't see a radiator cap. Thanks for any ideas.
Help with Low Coolant light on Silverado
- Thread starter jd0716
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FredH
Platinum Member
Is there a sensor screwed into the surge / over flow tank ? Not sure about your vehicle , but on both Semi's that I have owned and the APU on current semi have a sensor screwed into the surge tank . When sensor goes bad , light comes on , and with semi , Flippin truck shuts down were ever you may be .
Your looking for a likely round type probe with 2 wires coming out the back .
Fred H.
Your looking for a likely round type probe with 2 wires coming out the back .
Fred H.
CurlyDave
Elite Member
I have had sensors like this on cars and light trucks.
As Fred says, look for something on the outside of the coolant overflow tank with wires coming out of it.
Many times the problem is only dirt accumulation of the optical part of the sensor. Before you spend any money, take the sensor off and clean it and the part of the overflow tank it looks at. I have had this fix the problem.
As Fred says, look for something on the outside of the coolant overflow tank with wires coming out of it.
Many times the problem is only dirt accumulation of the optical part of the sensor. Before you spend any money, take the sensor off and clean it and the part of the overflow tank it looks at. I have had this fix the problem.
Toyboy
Platinum Member
My '05 has a similar problem w/washer fluid.
yooper1
Veteran Member
On the Chevy Talk board, there are a few discussions on the low coolant light.
Sounds like it has / is a problem for the years around yours
Sensor is supposedly in the reservoir. They say just change it out
Here is one:
low coolant/service 4WD - ChevyTalk --The Social Network for Chevy Fans
Sounds like it has / is a problem for the years around yours
Sensor is supposedly in the reservoir. They say just change it out
Here is one:
low coolant/service 4WD - ChevyTalk --The Social Network for Chevy Fans
The Haymaker
Veteran Member
Just be thankful you are only dealing with a reservoir sensor. 
[ame=http://www.youtube.com/watch?v=QgSuN6B5_Ck]Replacing a Heater Core 2001 Chevy Tahoe - YouTube[/ame]
Got on a track to find out how to replace the core after spending a few hours tearing my dash apart to clean as much of the heating/cooling system I could reach because my seldom used truck has picked up a few rodent inhabitants. Never did find core or condenser. Now I know why!
Good old GM engineering. They make it so you can remove the blower motor with no tools by turning it 1.5" , yet you need a Hurst Tool to service the system.
[ame=http://www.youtube.com/watch?v=QgSuN6B5_Ck]Replacing a Heater Core 2001 Chevy Tahoe - YouTube[/ame]
Got on a track to find out how to replace the core after spending a few hours tearing my dash apart to clean as much of the heating/cooling system I could reach because my seldom used truck has picked up a few rodent inhabitants. Never did find core or condenser. Now I know why!
Good old GM engineering. They make it so you can remove the blower motor with no tools by turning it 1.5" , yet you need a Hurst Tool to service the system.
Willl
Elite Member
Wife had a Cavalier that had the same problem, float sensor in tank was sticking.
Pulled tank and added a mix of simple green and water and shook the heck out of it. Rinse and repeat X2. Reinstalled and never had another problem.
Pulled tank and added a mix of simple green and water and shook the heck out of it. Rinse and repeat X2. Reinstalled and never had another problem.
WilliamBos
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Just be thankful you are only dealing with a reservoir sensor.
Replacing a Heater Core 2001 Chevy Tahoe - YouTube
Got on a track to find out how to replace the core after spending a few hours tearing my dash apart to clean as much of the heating/cooling system I could reach because my seldom used truck has picked up a few rodent inhabitants. Never did find core or condenser. Now I know why!
Good old GM engineering. They make it so you can remove the blower motor with no tools by turning it 1.5" , yet you need a Hurst Tool to service the system.
Thanks for the tip.
I messed with the truck today. I disconnected the battery for about an hour, reconnected it and still had the same issue. I even tried disconnecting the wire that goes to the surge tank and the darn light still came on. I am not great when it comes to working on cars, beyond brakes, plugs, oil changes, etc..., but this seems like it should be simple. But I am still stumped.
I don't think i mentioned in my initial post, but the light comes on after about 30 - 60 seconds.
I called AutoZone to see if they have the sensor I need and the employee I spoke to said there is a radiator coolant sensor but it isn't serviceable. He couldn't find any sensors listed for the surge tank. Am I correct in thinking the thing on the bottom of the surge tank with wires going to it is the sensor? Thanks.
I don't think i mentioned in my initial post, but the light comes on after about 30 - 60 seconds.
I called AutoZone to see if they have the sensor I need and the employee I spoke to said there is a radiator coolant sensor but it isn't serviceable. He couldn't find any sensors listed for the surge tank. Am I correct in thinking the thing on the bottom of the surge tank with wires going to it is the sensor? Thanks.
yooper1
Veteran Member
I guessed at your engine size and other info but Dorman shows
Part # 603-102
2008-99 Sierra, Silverado, 2006-02 Avalanche, 2006-00 Suburban, Tahoe, Yukon, 2004-02 Escalade, 2008-04 H2
Type : Coolant Reservoir
Make : GM
OE# : 15203949; 15808716; 15808715
Description : Low Fluid Sensor Included
Brand : Dorman - OE Solutions
see it here:
Dorman Products - 603-102
I used these numbers:
2002 > CHEVROLET TRUCK > SILVERADO 1500 > V8 - 5.3L (323 CID): FLEX: FI: N: Z
you can start your own search here:
Dorman Products
dorman is a product readily available at parts stores
The Auto Value Parts store here in town use them a lot for replacement parts.
I hope this helps
Part # 603-102
2008-99 Sierra, Silverado, 2006-02 Avalanche, 2006-00 Suburban, Tahoe, Yukon, 2004-02 Escalade, 2008-04 H2
Type : Coolant Reservoir
Make : GM
OE# : 15203949; 15808716; 15808715
Description : Low Fluid Sensor Included
Brand : Dorman - OE Solutions
see it here:
Dorman Products - 603-102
I used these numbers:
2002 > CHEVROLET TRUCK > SILVERADO 1500 > V8 - 5.3L (323 CID): FLEX: FI: N: Z
you can start your own search here:
Dorman Products
dorman is a product readily available at parts stores
The Auto Value Parts store here in town use them a lot for replacement parts.
I hope this helps
yooper1
Veteran Member
and if you google Dorman 603-102
you get these for prices and places:
dorman 603-102 - Google Search
from the mid $20 range to $50
you get these for prices and places:
dorman 603-102 - Google Search
from the mid $20 range to $50
Thanks yooper, I will do a search. I have the 2500 HD with a 6.0 engine. Am I correct that the sensor is what the wire was connected to at the surge tank? DDo you know why the light would still come on if I disconnected the wire?
yooper1
Veteran Member
yooper1
Veteran Member
Sorry I do not have an answer to why that would happen.
Maybe post your question over on the Chevy Talk board in the correct truck sub forum. Those guys are pretty sharp
Could it be possible that the light comes on when the wire is removed because it thinks the sensor is either missing or totally shot?
Some electric switches work to complete a circuit to work and some may show an open circuit as a working circuit.
In other words, it may need the sensor connected to complete the circuit....maybe
I guess I am not sure
Maybe post your question over on the Chevy Talk board in the correct truck sub forum. Those guys are pretty sharp
Could it be possible that the light comes on when the wire is removed because it thinks the sensor is either missing or totally shot?
Some electric switches work to complete a circuit to work and some may show an open circuit as a working circuit.
In other words, it may need the sensor connected to complete the circuit....maybe
I guess I am not sure
yooper1
Veteran Member
a search for a 6 liter 2500 shows the same
Coolant Recovery Tank | 2002 Chevrolet Silverado 2500 4WD 8 Cylinders U 6.0L SFI | AutoZone.com
Coolant Recovery Tank | 2002 Chevrolet Silverado 2500 4WD 8 Cylinders U 6.0L SFI | AutoZone.com
yooper1
Veteran Member
and just to be clear and cover my rear from getting jumped on...
my advice/ opinion / idea is just that...MY OPINION.
I am in no way saying it is definitely the problem and that the fix is the sensor / tank.
Some members here have a tendency to jump on others for offering advice and opinions that are not to their liking or that they think are not correct, therefore ruining TBN's friendly helpful neighbor feeling.
my advice/ opinion / idea is just that...MY OPINION.
I am in no way saying it is definitely the problem and that the fix is the sensor / tank.
Some members here have a tendency to jump on others for offering advice and opinions that are not to their liking or that they think are not correct, therefore ruining TBN's friendly helpful neighbor feeling.
lol yooper, I won't get on your case. I really appreciate your help and won't give you any grief. After all, I asked for help and you are helping me. My other option is to just take it in to the mechanic. It just seems like it is something fairly simple. Thanks again.
The Haymaker
Veteran Member
If you unplug a sensor, usually whatever is connected to it sees a "fault".
Pull the tank and flush it as someone else mentioned. Free is usually best unless the amount of labor involved makes it more practical to just replace and be once and done.
I gotta say, based on questions asked and comments made, you may just want to step away from the vehicle and let someone qualified take it. This is not meant as insulting, just personal experience and years of offering online tech help to those without mechanical knowledge and skill.
Pull the tank and flush it as someone else mentioned. Free is usually best unless the amount of labor involved makes it more practical to just replace and be once and done.
I gotta say, based on questions asked and comments made, you may just want to step away from the vehicle and let someone qualified take it. This is not meant as insulting, just personal experience and years of offering online tech help to those without mechanical knowledge and skill.
FredH
Platinum Member
As JD mentioned , you usually cannot just dis-connect the sensor , since when it faults , it is acting disconnected . My semi has 2 wires to back of plug on sensor . I disconnected and jumped the 2 connections with a small piece of wire to diagnose my issue . With a single wire , ????? I would think that wire would have some sort of voltage , then it would ground through the body of the tank , but if tank is plastic ?????????????????
Fred H.
Fred H.
