Best fix for small internal coolant leak?

[Silverado]

Last UOA showed elevated sodium, and coolant level has dropped a little in the overflow tub. I wont take further action untill my next UOA shows more evidence. But if in fact I do have a small internal coolant leak, what would you suggest?

Vehicle is a 97 Chevy silverado, with a 50/50 mix of dex-cool and water. Stock radiator is being used. The drop in coolant has taken place over about a year when I first installed my new engine.

 

[c_rossman]

Bars Leak, it is actually factory fill in 90% of all new vehicles.

 

[Silverado]

So would you guys suggest a coolant flush then refill with a clean 50/50 dex-cool/demineralized water mix.....in addition to the bars leak?

 

[seotaji]

quote:

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Bars Leak, it is actually factory fill in 90% of all new vehicles.

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I'm guessing japanese cars are in the 10% that don't use it. I know the domestics use them, like GM.

You can give 'er a cheap fix that may or may not work...but it's well worth trying...

Old-timers can tell you all about "liquid glass"...or sodium silicate. Many a car with a cracked block or a crack in a cylinder or head or a blown head gasket has made a few extra miles using this old-school patch-up.

Used to be that you could get the stuff at drug stores, back when they actually stocked some chemicals (we used to make our own gunpowder back in the day). Now, several companies offer their new and improved formula.

K&W sells their Block Seal. Prestone also offers a formulation, and Car Quest carries it in-house as well. Most of the modern formulas also contain copper as well, and may be called metallic block sealers. You do need to follow the directions explicitly. If you leave the stuff in your radiator too long, it can actually stop up the flues in the radiator. Anytime it's exposed to external air or dry heat (such as combustion chamber) it will harden solid as a rock.

There are really no holes that can get plugged up using the block sealer AS LONG AS THE SYSTEM STAYS REASONABLY FULL DURING THE PROCEDURE. That includes bleeding out any unnecessary air in the system. You have to drain the system and let it sit overnight to cure completely (including removing a block plug), but it's not really that risky.

 

[Silverado]

I am still not 100% sure that I have an internal coolant leak...just a suspician. Its just that I have never had to deal with that problem before on a vehicle. I will make my decision after recieving the results from my next UOA.

Sodium levels have gone from 5..10..15 on my 3 previous used oil analysis. I see a very scary trend, but not sure how worried I should be about sodium at those particular levels.

 

[Slick 55]

Your next step is new intake gaskets. There's no avoiding it unless you want to ruin the motor.

 

[Silverado]

Is 15 ppm of sodium going to ruin my engine?

 

[ebaker]

GM parts may still sell block sealer. They are big tablets that look like compressed sawdust. They were the factory fix for porous aluminum parts on older Cadillacs. I've used it succesfully on a couple of cars including a Porsche 928 that lost coolant.