Several manufacturers built 3800. Without that information no answer can be given
You will need a intake manifold set and possibly a plenum gasket set.
Bend over the mechanics counter.
To replace the intake manifold gasket on a 1999 Pontiac Bonneville with a 3800 engine, first disconnect the battery and remove any components obstructing access to the intake manifold, such as the air intake and throttle body. Drain the coolant and detach the intake manifold by loosening the bolts in a specific sequence to avoid warping. Clean the mating surfaces thoroughly, then install the new gasket and reassemble the manifold, ensuring all bolts are torqued to the manufacturer's specifications. Finally, refill the coolant, reconnect the battery, and start the engine to check for leaks.
replace the water heater inlet pipe on the intake manifold on a 3800
Replacing a lower intake manifold gasket on a 3800 V6 engine typically takes about 4 to 6 hours for a skilled mechanic, depending on the specific vehicle and any additional complications that may arise during the process. This job involves removing various components such as the intake manifold, and it can vary based on the mechanic's experience and the tools available. If you're doing it yourself, it may take longer, especially if you're unfamiliar with the engine layout.
If it is a gm 3800 you need to replace the upper intake. It has a crack in it.
What was the situation with DexCool and the Chevrolet 3800 series II engine and how do i get the replacement intake manifold from Auto-zone and what is the part #
front side of plastic intake manifold
In my Chevy 1500 with the 305 Vortec, the problem was the lower intake manifold gasket, which is the one that seals it to the engine block. On your 3800 V6 (in a Silverado? I didn't know that; I thought it was the 4.3, maybe it's an older or newer year than my body style), it could very well be the same. There is also a coolant line coming out of the manifold, if I'm not mistaken. Could be to the thermostat, but I don't have the truck anymore. To the best of my knowledge, that would be the easiest and cheapest thing to check.
The Manifold Absolute Pressure (MAP) sensor is located near the throttle body on the intake manifold.
The lower intake manifold gaskets on 3800 engines are likely to go bad at around 80,000 miles. This is caused from the gaskets being made with rubber and being eaten away by the "So-Called Dexcool" coolant. It is best to replace this gasket as well as the upper plenum gasket with a metal gaskets and change from dexcool coolant to regular antifreeze. This is an expensive repair...so be prepared.
A gm 3.8 l v6 or 3800 cc engine cannot have antifreeze in exhaust without first getting into the engine. If its getting into the exhaust it may be entering the cumbustion chambers through a damaged cylinder head or head gasket. Also this engine depending on the model year may have issues with the intake manifold gasket, that can cause antifreeze to leak into the engine oil.