I've noticed where antifreeze has been leaking on my driveway after my 2000 Maxima sits all day and night. If I drive it daily I don't really notice anything on the driveway over night. I've had a pressure check done on the coolant system which is supposed to show any leaks but it didn't show any. Has anyone heard of a water pump only leaking when it isn't under pressure like after my car sits for a longer period of time and when or while it has pressure it doesn't leak? We didn't see any leaks around the hoses or radiator. The threads I did check on here didn't mention anything like this. Thanks.

 

In my experience that is when the water pump leak is most evident -right after you shut the engine off and the heat & pressure build up. The coolant is no longer circulating, the pressure builds, and coolant runs out the water pump weep hole.

It may be leaking a little while running also but you might not notice it.

 

Double check the radiator hose for any leaks, or the hose compress during high rpm. Check the radiator cap and the coolant reservoir. The possibility that your radiator is clogged partially or your water pump is going . Check exactly where is the location of the leak (driver side or passenger). Place a brown cardboard under the hood and check for the leaks.

 

Thanks for the replies. I put a clear piece of plastic under the area and it was like a neon greenish/yellow color. I put some die in the radiator the other day thinking maybe I could find it that way. I'm going to clean underneath the car in the area of the leak and see if I can find it. It for sure leaks more the longer the car sits like overnight and all the next day. It seems to leak only or at least the majority of the leak when there's no pressure and the engine has had several hours to cool down. I guess that's why there was no leaks when I had the pressure check done. I can drive the car somewhere and come back out 30-60 minutes later and there's no leaks under the car. To me it doesn't make any sense. I'll try what I said earlier and see if I can find where it's coming from. I might take it to the shop and let them keep it overnight and see if they can locate the leak. Thanks again.

 

Is the leak on the right side of the car when you are standing in front of the car?

 

It's on the left side standing in front of the car. A little ways over to the right of the left wheel. If I want to jack up the front passenger side to clean underneath the car where's the best support place to put the jack?

 

You could jack the car up right in the middle - there is a notch in the crossmember, that spot is designated specifically for that task. Make sure to block rear wheels while you are lifting a car in that spot.

From your description, I have to agree with comments above. It sounds like water pump seals leak.

 

The best thing to do is to determine as close as you can where the leak is dropping from on the ground and go up from there. Unless it is real dirty and greasy, you should be able to see stains from the leak, even if it is dry.

 

probably radiator

 

Sounds like a bad water pump seal if it is coming from the left side. Usually when the car is running or the weather is warm the seal heats up and expands. I had a 2000 and drove it like that for a few years. Summer time was fine, but on cold winter days the leak was there. Just keep an eye on the overflow tank and make sure it is topped off.

 

Thanks for the info on where to place the jack to lift the front. I figured there had to be a place to jack it up, but I never could locate it. I hope after I clean underneath I might see where the leak is coming from. I really like and enjoy driving this car but every time something goes wrong it's costly. First it was a O2sensor, then coil packs, rear struts, now possibly a water pump which I was told could cost $450 parts and labor. Of course when I look at the 230,000 miles on it I can't complain too much. Things are going to wear out eventually.

 

Just an update...The shop that did the pressure check on my car to see if there were any antifreeze leaks, and couldn't, suggested that I try a new radiator cap. I really didn't think this would solve my leak because I never saw anything around the cap or down either side of the radiator. I went ahead and replaced the cap and I haven't seen any leaks on the ground in about two weeks. If it was the water pump I don't guess it would go two weeks or longer without leaking and then start again....or can it? Well in either case I'm just hoping this took care of the problem....for now anyway.