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Fellas,

I have my suspicions to what is wrong but I'll run it by you guys for your thoughts. '96 Buick Regal with 90k miles on it. 3800 II engine.

She's drinking coolant. Had coolant flushed and changed out last year. Found leaking plastic elbow fitting between water pump housing and manifold. Changed it and seemed to stop using coolant. Now it is using coolant again. No white smoke out exhaust. No coolant puddles on ground under car. No leaking plastic elbow. No coolant in oil. Three weeks ago put a can of stop leak in radiator. No change.

Thinking it is upper manifold gasket or horror of all horrors a head gasket. Seems to me a head gasket would have more severe symptoms. Any ideas?
 

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The upper intake is plastic. It doesn't have a gasket. It uses an O-ring type seal. The studs that hold the intake down have multiple nuts holding other items such as fuel rails, etc. Loosening of the bolts would be impossible.

The EGR port uses a piece of stainless tubing that runs from the lower intake up threw the upper intake in route to the throttle body. Where it enters the upper intake, the plastic will be melted and warped......Dan
 

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boatbob2
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Eating coolant....

HI,,is your oil gray or white? if so,chances are that the intake manifold gasket (actually like a big O-ring)not sure what its called...to replace it is a B---=H..i just paid $855.00 to replace mine.very tough job... :( :( :(
 

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If it is a plastic intake engine, as mentioned above the plastic warps and will leak into the engine. Sometimes the leak is so small it wont smoke much. I have seen them leak so bad they will hydrolock the engine.
If you can borrow or rent a cooling system pressure tester you should be able to find it to be sure.
 

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Yes, how I remember that. My third ex-wife was driving our LeSabre into town when it locked up solid. She had it towed to the dealer and was quoted $785.00 for repair. On a two year old car with a service bulletin issued.

I chewed the service managers *** and got the zone guy on the phone. They fixed the car for cost of fluids and other piddley stuff. Tho they did get me for $105.00 on one plug wire. Bunch of thieves.
 

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cool rockin daddy said:
About how long of a job is replacing the intake gaskets, Greg? Just trying to line up when I can do the job.

Took a couple of hours to do, but I took my time since these were the only two I've had apart. I did replace the plenum on one of them because of warpage, but the other one was the fault of the intake gaskets. In any case, I replaced the intake gaskets on both vehicles.
 

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Same thing happened on my 95 Bonneville. Wasn't worth the cost to repair it. It was a great running car until that P.O.S. intake plenum went T*Ts up. The paint was shot, the struts were shot, and the roof leaked. Time to call it a day and send it off to the crusher. I think it's called engineered obsolecense. I wouldn't be surprised if the lousy intake plenum was made in China. The engine died just as I pulled into my driveway. I used to have a lot of respect for Pontiac, and GM. Not any more. Unfortunately, I have a 2003 Express van, and I expect the same thing to hapen to that too. GM sucks.
 

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think outside the box

Also can be your heather core inside your dashboard... any smells or fluids like A/C drips?. Sometimes we think is A/C cond driping down but it could be something else!!!
A very small leak in the part of the car is very hard to track!! good luck.
 

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Upper intake problems are pretty common on 3.8s. Two things I would check first are radiator cap (as has been mentioned). If its not holding proper pressure, its either letting rampant evaporation, or just letting the coolant overflow out.

The other thing to check is the TB gasket. There are several intake configurations, but if I'm not mistaken, yours has a water passage in the TB gasket. They are prone to leaking and there is enough leak to notice, but not enough to make smoke or steam out the exhaust.
 
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