onthemat

Every morning for the last few days I've had to add about 16 oz's of water to the radiator. There are no leaks that I can find, as in nothing leaking to the ground. There is no coolant dripping from the exhaust or smoke. I don't smell any burned antifreeze. The oil is regular and not milky or overfull. The car is running fine and not overheating, and the overflow bottle is at the right level.

I am out of ideas. Anyone else have a suggestion?

Bayer-Z28

How long have you had the car? Have you done any work on it lately?? THeir might be some air pockets left in the collant system from something. You might not allways notice a smell or smoke from the exhaust when it comes to a collant consumption problem. If you are adding collant and you don't notice any on the ground, then it has to be going somewhere...

onthemat

It was flushed 4 or 5 months ago, but I've had the car for 2 years. No, I haven't done anything to the engine in several months. I first noticed it when it got really hot (outside air temp) around 95 degrees.

Would it make since that there could have been a pocket of air in it that long and since it really heated up it finally worked it's way to the top?

87DJP2001

Get it pressure tested for location of the leak.

lt11997

Possibly heater core, did you check to see if the carpet is wet on the passenger side?

onthemat

The carpet is dry.

moparman

I chased a mysterious leak for about a month. I pumped it up, cold, and it would hold pressure. It would only leak after the car was good and warm. I thought sure it was a head gasket, but it had no symptoms of a blown head gasket. Changed radiator cap, still missing coolant. There was no sign of any coolant on the driveway, or on the radiator. One day, when it was over 90 degrees, I drove to a local mall, and when I came out, I saw coolant underneath the car. I raised the hood, and good see where coolant had sprayed on the ac compressor pulley, and bottom front of the engine. I thought a hose had burst. However, it turned out the plastic radiator tank, on the passenger side, had a crack in it. Theory is the crack would widen when the coolant was hot, allowing it to leak, and close up as the engine cooled down, stopping the leak. So, look for leaks around the plastic parts of the radiator.

ACE1252

I had something like this happen to me on my 90 3.1 Z24. It would idle rough on start up and idle normal when warmed up. It was losing coolant with no leaks. After a week of adding a some amount of water everyday to the system, I took it into the dealer for a look.

It turned out there was a small crack in the number 3 cylinder wall. When the engine was cold the crack was wide enough to allow enough coolant into the cylinder to interfere with combustion. As it got hot, it expanded and closed the crack up enough to allow it to run smooth.

I'm not saying that is your problem, but that coolant is going somewhere.

pearlpurple

Yes this where I would start. Go to Autozone or Advance and borrow a cooling system pressure tester.

I had a similar situation a couple of years ago where coolant was missing and same as the poster of this thread with no obvious reasons.

Pressure testing, observed pressure drop slowly indicating a small leak, went to start it up to see if I could see the needle bounce indicating compression pressure in the cooling system and the engine hydrolocked as I turned the key. Got it going many many smokey smokey pulled it in garage, changed head gaskets, happy, happy ending.

onthemat

I have been checking the overflow daily and I finally notice that the level is way to high. It was hard to tell right away because the dipstick on my car is not to easy to read. It was actualy fuller then I thought. I'm going to get a new cap and that should take care of it.

Thanks for all the suggestions.

littlbasterd

did you do a block check??????