core plug whoops!!!

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Apr 30, 2009 | 08:00 PM

tralfamadorian

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core plug whoops!!!

Hey Guys:
My mechanic did some work to my truck, and one of the things that he replaced was the core plug that is on the side of the block, under and behind the exhaust manifold. The plug is the one that is closest to the front of the truck. Anyways, he replaced it with one of those rubber expanding ones, not just the metal one that you pound in. I assume he did this because there is not much room to manuever a hammer and socket in that area. However, I drove it home and noticed that it is leaking. It is losing about half of the radiator overnight. It is also interesting to note that when I fill up the radiator and run the truck, it does not leak. It only leaks when the truck is cold. I assume thi is because of the rubber expanding as the engine heats up (correct me if I am wrong). So: I need to fix this. Is the proper method just to loosen the bolt, pound until flush, and then re-tighten the bejeezus out of it? How should I go about fixing this? Should I move up a size on the plug? I have never replaced a core plug with one of the rubber ones before. I have always used the metal ones. Seems like the rubber ones are kind of crappy. I just don't want to take out the manifold, etc . to gain room to install a metal one. Thanks for the help.

Apr 30, 2009 | 09:26 PM

flipklos

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From: Wahpeton ND

The rubber ones are a temp fix for when your 500 miles from home and tools.
Throw It away and install a real aluminum or brass plug. Use a bit of permatex on it too.

You will most likely have to remove the intake and exhaust manifolds. Gaskets are about $15, plug $5. Finding a mechanic that does what you want-Priceless

Apr 30, 2009 | 11:53 PM

kernel-panic

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From: Yokosuka, Honshu, Japan

I got 5 bucks that says the mechanic didn't clean the hole before installing that plug, too. Most engine block heater plugs are similar. I had to clean the one on my BII up because it was leaking fluid and replace the bolt/nut so it would tighten down and seal properly. They can be a headache, but the rubber ones aren't too bad - but I would agree, they are a temporary fix at best.

May 1, 2009 | 12:22 AM

tralfamadorian

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maybe i can get enough room in there to get a swing on the hammer so i can get a metal plug in. how hard are the exhaust manifolds to get out? and i need a new gasket for it? when i replaced the freeze plug on the back of the block, the guy at the parts store recommended the rubber one, which i did not go with. they seemed kind of janky at the time, and now my suspicion has been confirmed. glad i did not put one in there, or i would be having to take the tranny out all over again.

May 1, 2009 | 07:57 AM

kernel-panic

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From: Yokosuka, Honshu, Japan

You'll have to pull the intake and exhaust manifolds 'together'. If it's an EFI engine, the exhaust manifold is a two-piece manifold. If it's a carb'ed engine, it's a one-piece and is usually held to the intake manifold with 3 bolts. They can be tricky to get off, but yes, you will have to replace the gasket(s). There are several on here that can give you tips and further info on this. I don't think you'd be able to get anything in there to install a brass / metal plug, other than maybe a porta-power and whatever you'd need to center it on the plug - and even then, you'd have to be careful not to damage your exhaust manifold.

May 1, 2009 | 08:28 PM

Harte3

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From: Spokane, WA

Just to be on the safe side, check the water pump...they are notorious for cold leaks when they are about to go out.

May 3, 2009 | 09:44 PM

tralfamadorian

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it was the core plug... the water pump does not look really healthy, but it was the core plug. i got a steel plug in the block, and as i drove it in i sealed it with permatex. it has not leaked since i put the steel one in. i took off the intaked manifold and that gained me enough room to get the plug in. thanks for your help, and don't use one of those rubber plugs unless it is last resort!!!!