Piston Slap: Morality and the Blown Head Gasket

Stargazer writes:

I have a slight head gasket leak in a 1993 GMC van, 350 cu. in. engine. I know that I will have to replace the gasket eventually; however, a friend suggested a head gasket sealant. This sealant drops into the radiator, and seals the leak. This friend had worked on cars professionally, so his recommendation has weight with me. Would you recommend this fix for a one hundred mile trip? I need the van to tow something.

Sajeev responds:

TTAC certainly has a lot of readers with vans. Which is somewhat awesome when you stop and think about it.

I think these gasket sealers (or block sealers) are a mixed bag. They can work, depending on the gasket’s condition. On a small block Chevy with iron block and heads, the odds of a quick re-seal are in your favor. Hell, it might handle the rigors of towing “without a hitch.” (Thank you, I’m here all week. Tell your friends.)

If this van is a keeper, there’s a downside: the cooling system gets coated with leftover sealant, making for a colossal mess for whomever tears into this motor. Who knows, you might need a new water pump or heater core after all is said and done.

If it’s not a keeper, then you have two distinct moral paths. There’s the path of righteousness and a path more, um, frequently chosen. Using such automotive band-aids so your hooptie van lives long enough to find a new owner is less than honorable. If greed is good, this is how you make some cash. But if you’re like me, you’ll tell the van’s next owner what you did, why you did it, what they could experience in the future. And maybe, just maybe, this is why nice guys always finish last; or why every van eventually winds up in a junkyard.

Technical question? Email Piston Slap: sajeev.mehta@thetruthaboutcars.com