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OT- Chevy low coolant light?

Discussion in 'Uncategorized Threads' started by SShooterZ, Aug 1, 2007.

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  1. SShooterZ

    SShooterZ Member

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    First thing I would do is scan the OBDII and see what code its throwing for the light to come on. Then see what that code relates to.
     
  2. 3200

    3200 TS Member

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    Got to an Auto-Zone or similar parts place. Often times they will scan your vehicle free of charge.
     
  3. g7777777

    g7777777 TS Supporters TS Supporters

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    the 3.1 engine was problematic - not like the bigger engine

    water pump would be my guess

    and they arent cheap

    but maybe it is nothing

    regards from Iowa

    Gene
     
  4. atashooter

    atashooter Member

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    It is a small sensor, one wire in the black radiator side tank. Make sure the new sensor comes with a new o-ring. 3.1's are real prone to air pockets in the cooling system and have "bleed valves " to relieve the air pocket also. They are also prone to leaks in the coolant system in many places, including a quick disconnect fitting up under the plenum, on the intake manifold. It is a PIG to replace. Water pumps common too. Have the system pressure tested before you do anything.
     
  5. Shady Creek

    Shady Creek TS Member

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    Add coolant to the reservoir, a "little" over full should do the trick. It worked on my Chev. PU. GOOD LUCK
     
  6. Bruce Specht

    Bruce Specht Well-Known Member

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    Near but not in chicago
    Shady Creek had the best answer, always start with the easiest solution to the problem. Coolant is a mixture of 50% water to coolant, it will evaporate some what. There is a sensor in some expansion tanks/ coolant resivors, the low coolant level light would indicate your vehicle is so equiped. Fill with coolant 50/50 mix, be sure to use the correct type of coolant as some chemcials can not be mixed. Your safest bet would be to by a name brand product that matches the type in your car. That information should be taged near the resivor or radiator or in the owners manual.
     
  7. Quack Shot

    Quack Shot Active Member

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    The coolant sensor in one of the radiator side tanks, depending on which radiator you have. It usually means that the coolant level is too low, when the light illuminates. You may check the coolant level in the radiator when it is STONE COLD, by removing the radiator cap. It needs to be filled to right near the top.

    You might need to "bleed" air from the cooling system and get it to the proper level. There are one or two bleeders in either side of the engine near the upper radiator hose and/or the bypass hose on the passenger side. This is a fairly complex procedure, but it can be done simply by opening the bleeders a slight amount and adding coolant to the radiator until it flows from the bleeders. It's best done cold.

    If you are losing coolant, you need to determine where it's going. Several areas of concern are common. Water pumps (Cheap 1 hour repair), Intake manifold gaskets, hoses, heater cores, radiators, etc. The Water pumps on these are real cheap ($30 or less for a NEW pump) and simple to replace. The hardest part is refilling the cooling system. The Intake Manifold gaskets can leak either internally, externally, or both, usually near one or both of the end rails. It's not a simple and easy job for a novice. If your oil looks foamy and gray you have a problem that requires immediate atention. If your oil filler cap has some foamy or sludgy looking goo on it, you might be at the beginning of the problem. A flourescent dye is the best way to determine the leak points, but it can usually be done with a simple pressure tester also.

    See this thread for info on replacing the water pump:

    http://www.trapshooters.com/cfpages/sthread.cfm?threadid=120106

    The coolant light is not regulated by the OBDII diagnostics, so no codes should be set. It is usually a separate system from the emissions system and pertains to a low coolant level. OBDII will monitor engine coolant temperatures and/or head temps and NOT coolant levels.
     
  8. ljunatic

    ljunatic Member

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    This is a common problem with the low coolant sensor.GM's DEXCOOL cooloant has some issues, and one of them is it's propensity to coagulate in some areas, like the coolant sensor. I think the sensor is an optical one, and the coagulated junk on it from the DEXCOOL causes a false reading. Replace the sensor and the problem may return later if your coolant needs to be flushed out and replaced. I am assuming that you have an otherwise full and normally functioning cooling system.
     
  9. Quack Shot

    Quack Shot Active Member

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    ljunatic

    You are certainly right about the DexCool. It's the first thing I get rid of on a GM. A real good flush or two and you are in business. Cleaning the sensor might fix the problem, but I have found that it's more often low coolant on a ten year old vehicle. I made a recommendation to flush the system and use a quality "regular" antifreeze in the thread I referenced in the post above.

    If the coolant levels are good, then a look at the sensor/circuit is in order. If the coolant is low, then you need to determine where it's going. Water pumps are easy to figure out. There will be a small trail of coolant running down from behind the pulley and there is usually a "wet" area down the passenger side of the engine.
     
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