OK , the low coolant light has been coming on after the car sits for a few hours (cold start) I'm very meticulous about keeping an eye on the fluid levels on this car, particularly because I know of the most common problems/failures with this car/ engine combo. So, the coolant level hasn't budged and the light comes on every morning. I'm guessing it's the sensor?? Ok...if it is, where is the sensor and can I get to it without being a contortionist?
Jay S
"Jay S" wrote
Are you simply checking the coolant level in the overflow bottle? If so, this is not always an accurate check on this vehicle. The low coolant sensor should be located in the radiator side tank, passenger side, about 4 inches below the rad cap. It's possible that the coolant level 'in the rad' is low. These vehicles do have a problem with the rad cap getting all gunked up with dexcool crap and this might cause problems with rad cap not allowing coolant to flow from the overflow back into the rad as the engine cools.
I would remove the rad cap when the vehicle is cold and check the level in the rad. Check the rad cap for scum all over it, and replace it if so. If you don't have low coolant, then it is also quite possible that the sensor is buggered. We replace quite a few of these 'in rad' sensors.
If you have low coolant, get ready to have the upper plenum removed to check for internal coolant leaks. In the case of your year of vehicle, you may only need an upper intake plenum gasket.
Ian
Hello, I have been following all messages relating to 3.8 L GM engine to learn more about Series II and possible series III on 2004 model. Just for my own information, I have seen one article 1997 Series II 3.8L with intake problem relating to EGR tube posted by R Kewl (excellent information and thanks for sharing). Does this mean that 1997 series II engine is diff. than 2000 series II since the message said just the gasket base on model year!? What change did GM made to rectify this problem. If they did, why couldn't they fix the gasket too? Furthermore, Am I right to assume that if you have series II engine with supercharge option (GTP or Bonneville SSEi) you would not have this problem since the intake and supercharged is made out of aluminum?
Regards, MN
None of these problems should be in the Series III motors. My car was a 98 but same problem is on the 97 too. I cant pin down which years are affected by this. Still learning that... GM had put the corrected lower intakes on the 2000 models from the factory. My guess is the gasket between the upper in lower fails which shouldnt be as hard to fix. Yes the supercharged versions of this engine are not affected by any of these problems nor are the f-body 3800's. However superchargers have to be rebuilt every 80k and thats about the same mileage the plastic intakes fail at.
I've kept an eye on the overflow and the rad. The rad and cap are nice and clean, no gunk anywhere to be found. I've checked it every couple days for a couple months now, the level never changes. Must be the sensor. The 1st time I saw that light come on I thought "oh no!" I've been keeping an eye on things from the day I bought it though so hopefully they'll be no surprises Thanks
Jay S
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