Where is my coolant going?

[muddpuppy]

My oil is clean and I have not found a leak anywhere. I add about a quart a week. I can't smel it in the exhaust.

[Macgyver55]

Make, model, year, engine size, miles..........?

[muddpuppy]

Sorry, 07 Impala 3.5 118,xxx miles

The car was not heating well so I ended up adding about a half Galon of 50/50 MIX, and about a quart a week since. I have not had any over heating at all. I drive about 700 miles a week if that helps at all. I am looking to do a presure test. But the car holds pressure for 5-10min after a good drive. So I am not sure there is much of a leak.

[Macgyver55]

This time of year cold water leaks are somewhat common. Connections can leak when they are cold because of contraction of the hose, but they quit leaking when they warm up. I suppose a waterpump could be the culprit, but that should show up with a visual or pressure test. Its hard in the winter to spot leaks with all the slush and spray, but watch underneath for any spots and their location. Also for very small, hard to detect leaks, GM makes a product called "seal tabs" that they actually recommend using, (and are designed for use in cooling system) to seal leaks and/or prevent leaks due to porosity in the engine castings.

[FishLocker]

You may have a minor head gasket leak that leaks into one of your cylinders. This time of year it is difficult to detect visually. In the summer you just look for a white exhaust which is heavy water vapor, and when it gets bad enough you can smell the sweet smell of antifreeze in the exhaust. But this time of year ALL exhaust looks white because of the cold.

If you know someone you can get large sheets of white paper, like drafting blue prints, you can put one under the car when you park at night to look for the tell tale color of your antifreeze.

I have used stop-leak products in the past with success, but not if I think it may be a head gasket leak as you may get some of the stop leak in your cylinder and end up scoring the cylinder. And it does not take much contamination to score a cylinder wall.

Good luck.

[mechanico]

I agree with fishlocker. Although a quart a week at 700 miles isn't much if you are burning it. It's probably too small an amount to smell. If you don't find a leak on the paper, you probably are burning it. That means a head gasket needs replaced. Depending on options your car has on it, it can be a pricey repair. Sorry, is a 3.5 a four banger? That would be a little cheeper. V-6's are awful to work on. I don't know about where you live, but around Indy the dealers are competitively priced on repairs.

ALTHOUGH, (different thought) have you checked to see if the carpet seems to be wet under the dashboard on the pasanger side? You could have a heater core leak. You could definetly tell if it's that, or eliminate it...

[muddpuppy]

Well I tried the white paper deal and didn't see anything, I have been qutoed 14-1500 for the head gasket. Is that ball park? Also should I also look at having the waterpump replaced at that time or just wait until it is needed?

[Jeremy airjer W]

I would have the car pressure checked after sitting over night and with the engine cold. Stubborn leaks can usually be found with a cold pressure check.

If its a head gasket you should be able to smell exhaust in the coolant bottle. With the engine cold remove the cap and give it a whiff. If it smells gassy or like exhaust you found the culprit. If not go with the cold pressure check.

The cost on the head gaskets is not bad.

[muddpuppy]

Well I got a presure tester and the leak was comming from the waterpump. I think it was a loose bolt or 2 blown gasket. How can you tell if the Waterpump is bad? Anyway I replaced the Waterpump, and a couple hoses. So far so good.

Thank you to all for your help.

[pureinsanity]

Water pumps are tricky. I have a new one put in my car with 54k on it. now im almost at 150K. Gonna be throwing a timing belt on it soon so I will replace the water pump as well even though it is in working order. A water pump can last 30k or 300k, it just depends.

Glad you got it fixed, water pumps aren't to expensive specially if you do it yourself. I am getting a timing kit and a water pump for about 150bucks for my VW