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Looking for a coolant leak in my Pontiac G6

The last couple of days I thought I smelled antifreeze and I had to add about a pint of coolant to the reservoir. So I looked all around today and can’t see anything leaking. Nothing on the floor. I suspected the water pump but looked pretty dry from what I could see. Thing is if its the pump, its still under warranty for a few months and 7,000 miles so want to find that pretty quick. Radiator is fairly new also from hitting a coon. Any tips? Not sure if a pressure test would detect a small or intermittant leak in the pump though.

Well Bing, you commited the basic mistake when posting a question. What year and what engine?

You should know better.


@Bing Have you performed a pressure test?

Some marginal seals and gaskets leak only when cold. When warmed up, they expand just enough to stop leaking.

That must have been some big animal you ran over!

BTW, have you crawled underneath the car and looked at the water pump weep hole? If it’s crusty looking, you may have found your leak.

I think a pressure test would find the leak. But me, I’d monitor the coolant level for a while, see if it is going down over time. Needing to add a pint may or may not be indicative of a leak, depending upon how long ago you last topped it up. Some small amount of coolant loss is to be expected. On my Corolla I need to add anywhere between a cup and and pint every 9-12 months or so.

Sorry, it’s an 09 with the 3.5 V6 N non-flex fuel.

Checked with mirrors and such and crawled under but its pretty tight in there. Didn’t see anything. Its time for a serpentine belt anyway so think I’ll have the guy take a look then from underneath with the shield off. Its really tight and can’t even get your hand in there to feel underneath.


Don’t you think you could do the belt yourself? Changing out a belt is usually not so difficult.
There are some exceptions. But I’ll not get into that. I’m sure everybody has their own personal horror story as far as that goes.

Taking off the splash shield should be just a matter of taking off a few bolts or clips.

Putting it up on jack stands and laying on a creeper should also make your inspection much more tolerable.

Good luck, in any case!

Nope, not on this one. The belt is about 5 feet long on about 6 pullies and no room to even see what you are doing, let alone reach them. Plus you gotta take the mount off. I’ll leave it to a younger person. I’ve never not done them before but not on this one. My Olds with the Northstar engine was pretty bad but this one is super bad.

Sorry to hear that.

FWIW I recently had to replace a serpentine belt on a truck on which I had to detension the old belt, unbolt the tensioner, remove the old belt, feed the new belt in, and then bolt the tensioner back on.