low coolant

My low coolant light was coming on, so had the system flushed. A week later, the light comes on again and had to add more coolant. There are no visable leaks, so where is it going? I have a 96 Bonneville SSE

 

check your engine oil just in case.

 

What does your exhaust look like?

 

run a leak down test on the cylinders to see if you have a bad head gasket, cracked head, block, or valve guide . have the cooling system pressure tested. check the cooolant overflow hose.

 

Well, first question is, WAS the coolant low? In other words, more than an inch or two below the cap on the expansion tank (I'm assuming you have an expansion tank, not a regular old radiator).

You say "The light was low, so I had to add more coolant" - but this doesn't necessarily follow. If you add TOO much, it steams out the overflow hose during operation, so you wouldn't see it puddling on your garage or driveway.

Many newer cars with expansion tanks have a 'built-in' low coolant sensor, and if the sensor goes bad, it can give a false reading.

Check with a qualified Pontiac mechanic, and verify that you are actually LOOSING coolant, before you spring for another flush (a bad idea generally anyway) or an expensive $$$$ repair you DON'T need.

 

v6? i'd suspect the intake gasket, felpro gaskets fix it better

 

it has to have a leak somewhere get the cooling system pressure tested. perhaps its the plastic upper intake if its a 3800 that melts the intake at the egr exhuast passage.

 

Is there a milky look to your engine oil. You can try Barsleak in cooling system to stop leaks Gm puts it in all new cars made.

 

Don't put bars leak in there!, GM puts thier own seal "tabs" in them. You can use stop leak, if your going to get rid of it that is.....

 

I have used bars leak for 25 years here in Canada where cold temp. always makes are cars leak a little at start up untill engine warms up.I have a 96 grand prix and I use bars leak in it for the last 6 years and never had to add any coolant to it.I an still driving this car today.

 

The GM "Coolant Supplement" is the exact same thing as Bars Leak GOLDEN SEAL - comes in tabs or tubes at your local Walmart. Exact same stuff. BUT not all "Bars Leaks" products are the same - just the "Golden Seal" variety.

 

Ahh yes, after searching around, it is made by them, but one thing to note, its made by them, for GM. I'm just a fix it and not cover it up person though....