96 Lumina; Check engine light and low coolant

My check engine light stays on all the time. I changed my oil and oil filter, transmision fluid, air filter, plugs, plug wires, and it still stays on. Any suggestions what to do next?

I am leaking coolant somewhere, but I'm not exactly sure where. The Low Coolant light does not come on, though. I got a part that it looks like it's where it is leaking from, but I'm not sure how to change it. I wish I could tell you what the part is, but I actually have no clue. It's to the right of the block. If you look under the car, it is dripping near the oil pan. Do I need to drain my radiator first?

Do you smell antifreeze inside the car, or have fogging problems with the defrosters on? If so, then you have a heater core leaking, and the coolant is coming from the drain tube for the heater box. What side of the car is the leak on, drivers or passengers? As far as the check engine light, your 96 requires a scan tool to pull the codes. Take your car to Auto-Zone or Advance Auto, they will scan it for free and tell you what component has caused your light to come on. Then after replacing the part, take it back and have them clear the code.

Might be the thermostat housing, if its the right side of the engine compartment near the pan. Remember, slow fluid leaks will play hell on you if you try to just trace their path. With all the curves, bumps, bosses, and grooves, along with wind from the fan or travel, the drip may be half a foot off vertical from where the leak actually is. But the only parts that are removable (that comes to mind) is the tstat housing, ECT, and bleeder. You'll probably want to drain the system before replacing anything simply to keep the amount of coolant spilled down. Just follow richtazz's advice, go grab some Autozone guy and have him read the codes.

There is no smell inside the car. If it's the heater core, there would be a leak on the passenger side on the floor board, right? Well, there is no leak in the car. My heater and defrost are blowing cool air. I took the car to Auto Zone, but the test showed that my #3 cylinder is misfiring and my ECG valve is out. (I think it was ECG; those may not be correct letters.) But nothing about the coolant leak. I believe the leak is coming from the driver side. It's hard to say. When you look under the car, it drips off the oil pan. I can't see exactly from where it is originating. I put some silver seal in the radiator and more coolant in today, so I should know by tomorrow if it fixed the problem. I'll get back to you then. Thanks a lot.

Okay, so maybe it was ECT. What is that? I mean, what does it stand for? I'm a decent little mechanic, at least in my mind. But I'm still learning! But apperently, the guy at Auto Zone had no idea of what he was speaking because he said he couldn't find anything to do with a leak. (Even though my radiator was close to dry!)

Okay, so maybe it was ECT. What is that? I mean, what does it stand for? I'm a decent little mechanic, at least in my mind. But I'm still learning! But apperently, the guy at Auto Zone had no idea of what he was speaking because he said he couldn't find anything to do with a leak. (Even though my radiator was close to dry!)

If the cooling system is low, it can set a ECT code because the engine does not get to operating temperature.
If you give us the code numbers that would help alot.
As far as your coolant leak, have you had someone pressure test the cooling system?
Also, what engine do you have? Is it the 3.1 or 3.4 V6 or the 3.4 dual overhead cam engine?

I don't know the code numbers. The guys at Auto Zone are kind of jerks to girls, so I don't get too far with them. I was going to get the codes to post on here, but, go figure, I got blown off before I could get the dude to give them to me.

I still don't know what ECT stands for. No, I haven't had anyone pressure test it. Who do I go to for that? It's a 3.1 V6

I recently had a coolant leak, wound up changing the intake manifold gasket. I started developing a misfire and scan said initially misfire on #3 cyclinder, developed into random, multiple misfire. I traced it down to failing hydrauli lifters. Replaced them and car had its original get up and go! Have it checked by certified mechanic for lifter failure. All this happened around 115k miles.

I recently had a coolant leak, wound up changing the intake manifold gasket. I started developing a misfire and scan said initially misfire on #3 cyclinder, developed into random, multiple misfire. I traced it down to failing hydrauli lifters. Replaced them and car had its original get up and go! Have it checked by certified mechanic for lifter failure. All this happened around 115k miles.



How much did all that cost you? Got 160k miles right now, but got the first #3 misfire code around 120k. I've changed my plugs and wires twice since then, but it's still there. The coolant leak and lifter failure weren't connected were they? Did changing the gasket fix the problem?

The lifters run about $270 for set of 12 and gasket set about $30. Labor was free since I did it myself. If your leaking coolant into motor you'll aalso need to flush the motor. After I did all this no more light and car runs perfectly. If you do this yourself, pay very close attention to the pushrods and the location they came out of, the intake and exhaust rods are different lengths.

I put the silver seal in my radiator the other day, and it seems to have worked. I checked my coolant level in the radiator and the reservoir this morning, and they are full. Thanks for your input. Now I have to get to work on the check engine light issue.

Hey Gmmerlin I have a 3.1L that hesistates some times under light throttle when the engine is cold? any ideas?