2001 Buick Lesabre losing coolant

My 2001 Buick Lesabre has always shown to run exactly normal on the temperature dash unit until recently. I checked my coolant level and it was a bit low, so I added. After I filled the radiator I have noticed a coolant leak spot on my driveway, after I drive it now. I have removed the gravel shield and have tried to pin point exactly where the leak is coming from, but cannot. Now, each time I park, after driving it, I put a clean piece of cardboard under it to try to see exactly what area the leak is coming from. Last night I put the car on ramps and crawled under to discover that the leak is located just above the oil filter and is actually dripping from the oil filter, but I still cannot see the exact location of the leak.
Actually the leak does not appear until about an hour after I park the car, so it sounds like something is contracting after the engine has cooled off, but what?
The leak has seemed to be getting worse each time I drive the car. How can I determine exactly where the leak is coming from without just changing a bunch of parts.

The only way is to pinpoint it.......

Usually if you see a leak near the oil filter, I would concentrate on two areas.....the w/p and the elbow that comes out of the tensioner assembly and goes into the lower intake.....

You can rent a coolant pressure tester at any parts store and pressurize the system to see if you can see the leak.....with pressure on the vehicle, grab that plastic elbow, and move it up and down slightly....if it's the source, it should leak under pressure with a little movement....

Sometimes it's hard to see coolant come out of the weep hole of the w/p.....with the belt still on, break free the four 8mm bolts on the front of the pulley....now release the tensioner and remove belt....remove 4 bolts and pop off the pulley(may stick a little)...if you find coolant on the inside of the pulley or evidence of coolant coming out of the weep hole underneath, you need a w/p.....

Thanks man, I will try that. Just needed a place to start and that sounds like a good place. Probably need to replace the water pump anyway. Is there a technical name for that little elbow and do you know if it would be available at a parts house?

Here is a picture:

http://ww2.justanswer.com/uploads/dt69nova/2010-07-01_214346_pic.gif

Have seen problems with aftermarket elbows, prefer OEM...replace both....

Both plastic and aluminum replacement elbows are available at auto part stores our online, eg RockAuto. I replaced with aluminum last year, but a friend said the o-rings on his aluminum elbows don't last, maybe because of increased thermal expansion. That's the only time I've heard of problems with them. They last much longer than plastic.

I have read that the Doorman replacement elbows are not recommended, what is your take on them? Also, yesterday, I noticed that the water pump may be making a noise now. Probably be a good idea to just go ahead and replace it, don't you think? One last question, If I replace the water pump, would you just go ahead and replace the two elbows also?

Dorman leaked on my 3.8, oe did not.

I haven't had a problem with the Dorman. I liked the idea of aluminum for durability.

Regardless of which elbows you choose, consider changing them if they haven't been changed recently. The replacement cost is low and the cooling system will be empty if you're changing the pump. It would suck if you replaced the pump and refilled and purged the air, then found you had an elbow leak.

At a minimum, pull them out and inspect and maybe change the O-rings. I've found that the plastic gets brittle and cracks.

I would also check the heater core hoses and radiator hoses and consider replacing those. My approach is those parts are cheap compared to my time to drain, flush, fill, and purge.

Thanks for all the advice. I am convinced and will start on the job today. I am no longer the speed demon that I once was, but I will let you know how it turns out. This is a great forum and it has really helped me what little time I have been a member. Everyone keep up the good work.

I'm back and I finally got the time and energy to start working on my 2001 Buick Lesabre. I took the belt tensioner off and immediately found the problem. One of the heater hose elbows is cracked and that is where my leak is coming from. The water pump seems fine and since I am not a rich person, I was thinking of just replacing the elbows with the new aluminum elbows and not replacing the water pump. Please give me your take on this decision and I just might bite the bullet and change my mind.

Your plan is good, especially if there's no evidence of water leaking at pump. Replace elbows and see what happens. You don't need to drain system.