2003 touring,coolant leak under timing cover

[takcruiser]

I have a coolant leak coming from around timing cover and support brace,changed thermostat and rad.cap,but was not over heating and fans working,any suggestions?

[rob302]

If you're sure that's where it's coming from, that would be the water pump

[JoeX]

Get it to operating temp and look closely to the air purge fitting and the base of the thermostat.
The thermostat housing is a sort of plastic and will bend or warp over time and may not be able
to hold the pressure of the system at the base where it contacts the aluminum thermostat base housing.

If either of these areas are completely dry, then I would agree with rob302

If you changed you timing belt, did you replace the water pump too?
How many miles ago?

[takcruiser]

Yes,I did do the water pump and timing belt 40 thousand miles ago

[takcruiser]

I am not saying I am going to do it,but is it a smart move to use stop leak to try and seal the leak if it is the pump?I have heard how temperamental these pts can be.dont want to clog something

[JoeX]

Originally Posted by takcruiser

I am not saying I am going to do it,but is it a smart move to use stop leak to try and seal the leak if it is the pump?I have heard how temperamental these pts can be.dont want to clog something

The stop leak might seal a small hole in the radiator, but I think it worthless if its the spinning shaft / seal on the water pump

[06_PB6_TOURING]

As stated, stop leak won't fix a water pump shaft seal. The _only_ stop leak to use on weepy leaks is Bars Leaks tablets, they are also branded under AC Delco ( GM ) and probably most other auto makers .

This is a tablet you crush, add to the cooling system then drive the car. The sealer won't clog a rad or heater core that already isn't a 1/2 step away from being clogged. It is mostly Ginger and some fine (saw? ) dust. It is stealth and doesn't make the coolant look like mud. In the 80's GM specifically recommended using this on "all " HT 4100 Caddy aluminum V8s to seal weepy leaks.

Now for something I only recommend on a car that is on it's last legs, when the gas in tank is worth more than the car, or emergency conditions not a permanent / sell the car fix.

There is a head gasket sealer called " Blue Devil" , at $ 60 a qt is is $$$ but it _will_ take a combustion chamber to coolant head gasket leak to near nothing. It contains "Silicon Silicate " AKA " Water Glass ", when mixed with water these fine strands are in suspension. When this mixture hits a leak the water is strained out and the glass fiber bond together ( heat helps also ) plugging the leak.

I used this on a 4.3 GM V6 that was starting to eat coolant. At that point in time, things were too busy to take it down. The sealer dramatically slowed coolant usage until I could take it apart. The head gasket was fine, the head had developed a slight low spot and this loss of clamping pressure allowed coolant to weep into the combustion chamber.