Head gasket or intake gasket?

Well, finally got around to replacing the noisy water pump on my '93 C1500 W/T today. When I was flushing the radiator out, I looked at the filler neck and noticed that there was a constant stream of tiny bubbles coming up out of the coolant whenever the engine is running.

Some of you may remember that I've been chasing problems with this truck since I bought it a couple months ago. I found that a tiny amount of coolant/water is getting into the #5 cylinder when the truck is shut off (rusty spark plug). It runs rough for a while on startup and after a minute or so, it runs perfect.

There is no water in the oil, and no visible leaks around the intake gasket... so I'm leaning toward thinking that this is a head gasket. I was really hoping that it was just an intake gasket leak, as it involves alot less headache to replace. But I don't believe a leaking intake gasket would cause the coolant bubbles, correct?

Whoever owned the truck before me put a Target-Master long-block in it. I have never had any kind of luck with Target-Masters in the past either, so I think therein lies the reason this is happening. Must be poor quality control at those factories (I think Target-Master engines are made in Mexico aren't they?).

-Tony

Reply to
Tony Kimmell
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Tony,

Head gaskets or a cracked head.

Doc

Reply to
"Doc"

I was led to believe Target engines are the ones that had problems on the assembly line and were removed from the vehicle sent back to engine plant and repaired. This is what a dealer told me 25 years ago. I'm not sure where the GM engine plant is now. As usual Doc is right on the money with diagnosis!

Reply to
Randd01

PS. If you remove the thermostat and housing and fill the radiator with antifreeze till it is at the level of the intake manifold and run it you can actually tell which head the air bubbles are coming from.

Reply to
Randd01

Bob your absolutly right i forgot the fan belt removal step thanks DUH!

Reply to
Randd01

TargetMaster engines are a prouduct of Delco I believe. From info I've got from a few others (as well as my own bad experiences with a couple other Target engines that were in other vehicles I've bought) my belief is that these engines are sub-standard at best. All the other Delco motors were V8's, this is the first one that I've had experience with in V6 form.

I've never seen a headgasket leak so slowly... you can't even tell there's anything wrong once the engine warms up, and it only eats about 1 quart of coolant a month, if even that much. Methinks the cracked head theory might not be too far off.

Looks like it's going to get a good dose of Copper-Seal before I put the antifreeze in. Doc's black pepper idea works great, but it only lasts about 1 week (you should have smelled the coolant I drained out of it... whew). Guess I might go looking for a used 4.3L to re-build for it, cause I'm definately not dicking around with the POS that's under the hood now. I'll drive it till it dies (could be a long time... it's been leaking like this for over 2 months now).

-Tony

Reply to
Tony Kimmell

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