Chevy Cavalier 2001 Cooling System Problem

I recently bought a 2001 Chevy Cavalier, which now has approx 65k miles. A few weeks ago we drove up the canyon for dinner. This car is gutless, and I usually respect that fact, but I was in a rush that night and kept the "pedal to the metal", causing it to shift gears to maintain speed. I don't know if this is related to my problem, but thought I'd mention it.

Anyway, after dinner I noticed a big puddle of orange coolant under the car. On the drive back down the canyon, the car started to overheat so I filled it with water. Two more times that week, I filled up the coolant tank with water, just to drive the 8 miles to work. Each time, while at work, the water leaked out in the parking lot.

I just assumed that there was a hole/leak in a hose, and no longer drove the car. Now I have time to investigate, so today I put it up on blocks and filled the coolant tank with water again. But now nothing is leaking out!! I idled the car, and even ran the air conditioning. Eventually after about 15 min, the heat gauge on the dash indicated very hot, so I turned it off.

Now I'm at a loss. What caused it to leak all of the coolant and water several times in several days? And now why is it NOT leaking water/coolant? Why is the engine overheating?

Thanks in advance!

Check the reservior pressure cap. It could also have a sticking thermostat. Maybe it was running hot and the coolant came out the pressure cap. When you fill the coolant you have to make sure to let all the air bleed out.

which engine?

This car is gutless
which engine?
I'd bet 2.2 OHV :)

Sometimes water pump seals will leak only while the engine is cooling down. When mine started leaking I could drive as long as I wanted, but when I shut the engine off it would start leaking within minutes

which engine?

Good question. I failed to mention that it's a bi-fuel CNG Cavalier. I don't know the particulars about that engine. :frown:


I'd bet 2.2 OHV :)

Sometimes water pump seals will leak only while the engine is cooling down. When mine started leaking I could drive as long as I wanted, but when I shut the engine off it would start leaking within minutes


Interesting that the leak would happen after the engine is shut off. I haven't observed that yet, but it might be what's happening to me too. So are water pump seals easy to replace? How much should I expect to pay a mechanic if I ask him to do it?

Thanks again!

If its a 2.2 a new water pump will run you a couple hundred bucks to have installed. If its a 2.4 it will be substantially more as the exhaust manifold and timing chain/cover need to be removed.

My 2.2 liter 2000 cavalier was doing the same thing and we discovered it was the water pump. At first it was leaking slow by right before I got it changed the water was pouring out of it. Got that changed now on here looking through threads to get ideas of the "new" issue after getting it changed. If you know someone who can change the water pump, I only paid 17.99 before tax for mine at autozone. Thats with a 1 year warranty.