Slowly losing coolant

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livingez_123

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if you had a leak in your radiator, you would smell it, even after its long gone the smell remains.
 

bottomline2000

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RTV on an LS water pump? New stock style rubber impregnated gaskets. I've reused the ones on my racecar dozens of times without a single leak.

Mike

Yep, I replaced the water pump on my truck with the rubber impregnated gaskets and there was always moisture on the outside of the pump.

I also have an 05 GTO and when I replaced the pump on it I ran a small bead of RTV around the edge of the gasket and it's dry as an old bone. Didn't take much and it worked.

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M Hankel

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Yep, I replaced the water pump on my truck with the rubber impregnated gaskets and there was always moisture on the outside of the pump.

I also have an 05 GTO and when I replaced the pump on it I ran a small bead of RTV around the edge of the gasket and it's dry as an old bone. Didn't take much and it worked.

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Hmm, the only thing I can think of is that you either got a faulty gasket, or the surfaces were not absolutely clean when they were reinstalled. I'd never recommend RTV on those gaskets for anything but an emergency fix. It's just not needed. The GM gaskets are great, the Felpro's rate a very close second and everything else is "install at your own risk" type of thing. The cheap Chinese knockoff gaskets that usually come with a replacement waterpump are the worst of the bunch, those go straight into the garbage can IMO.

I hope this doesn't come across as argumentative. It's just that one of the great things about working on the LS engines is the fact that you DON'T have to use RTV for every gasket surface. I owned many a sbc and scraping old gasket/RTV material off the surfaces got really old. It just seems like using RTV on a LS engine is taking a huge step backwards on the evolutionary scale. I cringe when my friends ask me for help on their SBC's now. I'm getting too old to scrape head gasket material off the decks of blocks lol....

Mike
 

livingez_123

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There are a couple of areas that a tiny drop is still needed, nothing like the old 1st gen sbc.
 

M Hankel

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There are a couple of areas that a tiny drop is still needed, nothing like the old 1st gen sbc.

Yes, the four corners of the pan gasket where the front/rear covers mate to the block. Only needed because of the differences in surface mating areas where the other gaskets stick out slightly. I usually trim those flat with a razor blade to minimize sealant use.

Mike
 

bottomline2000

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Hmm, the only thing I can think of is that you either got a faulty gasket, or the surfaces were not absolutely clean when they were reinstalled. I'd never recommend RTV on those gaskets for anything but an emergency fix. It's just not needed. The GM gaskets are great, the Felpro's rate a very close second and everything else is "install at your own risk" type of thing. The cheap Chinese knockoff gaskets that usually come with a replacement waterpump are the worst of the bunch, those go straight into the garbage can IMO.

I hope this doesn't come across as argumentative. It's just that one of the great things about working on the LS engines is the fact that you DON'T have to use RTV for every gasket surface. I owned many a sbc and scraping old gasket/RTV material off the surfaces got really old. It just seems like using RTV on a LS engine is taking a huge step backwards on the evolutionary scale. I cringe when my friends ask me for help on their SBC's now. I'm getting too old to scrape head gasket material off the decks of blocks lol....

Mike

In all fairness I can't say what brand of gasket I got. Didn't know there was a difference in brand quality. My GTO runs great and has had zero issues. It's not like I ran a full bead of RTV. It was only a thin layer outside the rubber portion of the gasket in case fluid did get past it.

I should be swapping the motor soon so I'll keep that in mind with the new water pump.

If it leaks u owe me a gasket replacement and a 6 speed swap lol.

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Wake

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Your inside windows fogged up in the mornings? If so, could have a small leak at the heater core...

That's exactly what I was thinking.

Also, how about the rear A/C and heating? I imagine that coolant must run through a tube to the back and a heater core exists back there as well. Leave a whole lot of area that could be leaking.
 

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