Water in tailpipe, rough idle on start,

[zonie77]

There is a thread in tech tips that will give you a lot of info on doing the HG's. It's titled something like Head Gasket repair part 1.

[Cad tech]

Disable the SIR. Refer to Disabling the SIR System in Restraints.
Recover the air-conditioning system. Refer to Refrigerant Recovery and Recharging in Heater Ventilation and Air Conditioning.
Remove the tower-to-tower brace.
Remove the air intake duct.
Remove the air cleaner assembly.
Remove the drain cooling system. Refer to Draining and Filling Cooling System in Engine Cooling.
Remove the radiator hose at the crossover.
Remove the engine cover.
Remove the radiator upper cover.
Remove the upper radiator hoses from the engine.
Remove the forward discriminating sensor from the radiator support and set it aside.
Remove the cooling fans. Refer to Cooling Fan Replacement - Electric in Engine Cooling.



Remove the transmission cooler lines from the radiator.
Remove the cruise control servo connections.
Remove the throttle and cruise control cables from the throttle body.
Remove the shift cable from the manual shift lever and the bracket.
Remove the vacuum hose from the brake booster.
Using J 37088-A disconnect the fuel inlet and return the lines.
Remove the coolant reservoir.
Remove the coolant hoses from the pipes at the front of the engine.
Remove the negative battery cable from the left cylinder head. Refer to

Caution
Before servicing any electrical component, the ignition key must be in the OFF or LOCK position and all electrical loads must be OFF, unless instructed otherwise in these procedures. If a tool or equipment could easily come in contact with a live exposed electrical terminal, also disconnect the negative battery cable. Failure to follow these precautions may cause personal injury and/or damage to the vehicle or its components.


in General Information.
Remove the positive battery cable from the battery and body retainer.
Remove the PCM case and the PCM.
Remove the right sound insulator.
Remove the engine wire harness electrical connector and the vacuum line under the instrument panel.
Remove the wire harness from the pass through at the cowl and pull the harness through the cowl.
Remove the three electrical connectors from the A/C line near the engine cowl.
Remove the vacuum hose from the "T" fitting near the engine harness pass through.
Remove the right and left front wheel speed sensor electrical connectors.
Remove the MAP sensor and the control motor near the master cylinder.
Remove the engine harness retainer from the brake booster.
Remove the two hoses from the power steering cooler.
Remove the engine harness from the hood fuse panel.
Remove the three relays from the lower radiator and the electrical connector from the ABS modulator.
Remove both tires and wheels.
Separate the drive axles from the steering knuckle. Refer to Drive Axle On-Vehicle Service.
Remove the post oxygen sensor heat shield.
Remove the post oxygen sensor wire harness connector from the body.
Remove the intermediate pipe hangers form the intermediate pipe. Refer to Engine Exhaust.
Remove the catalytic converter from the pipe. Refer to Engine Exhaust.
Remove the steering coupling from the steering gear. Refer to Steering Wheel and Column.
Remove the fuel line bundle from the transmission.
Remove the battery wire from the generator.
Remove the A/C manifold from the A/C compressor. Refer to Compressor Replacement in Heater Ventilation and Air Conditioning.
Remove the ABS modulator from the frame and support.
Position the powertrain support table J 39580 under the frame and lower the vehicle onto the table.
Remove the six frame to body bolts.
Raise the body off the powertrain.
Remove the coolant crossover pipe from the engine.
Remove the Park/Neutral switch from the transmission.
Remove the engine wire harness.
Remove the exhaust "Y" pipe. Refer to Engine Exhaust.
Remove the accessory drive belt. Refer to Drive Belt Replacement .
Remove the power steering pump and hoses. Refer to Power Steering Gear Replacement in Power Steering System.
Remove the generator and the bracket. Refer to Generator Replacement in Engine Electrical.
Remove the A/C compressor and the bracket. Refer to Compressor Replacement in Heater Ventilation and Air Conditioning.
Remove the idler pulley.



Remove the right engine to transmission brace.



Remove the lower engine to the transmission brace.
Remove the left engine to the transmission brace.
Attach the engine lift to the engine.
Remove the left engine mount and bracket.
Remove the left exhaust manifold. Refer to Exhaust Manifold Replacement.
Remove the flywheel inspection cover.
Remove the torque converter from the flywheel.
Remove the right engine mount bracket from the engine.



Remove the transmission (bell housing) to engine bolts.
Remove the engine from the transmission and frame assembly.
Remove the cross under pipe, EGR.
Remove the right exhaust manifold. Refer to Exhaust Manifold Replacement.
The intake manifold. Refer to Intake Manifold Replacement .
The left side cam cover. Refer to Camshaft Cover Replacement.
The right side cam cover. Refer to Camshaft Cover Replacement.
The crankshaft balancer. Refer to Crankshaft Balancer Replacement .
The engine front cover. Refer to Engine Front Cover Replacement .
Align the timing marks.
Remove the chain tensioner from the timing chain for the cylinder head being removed.
Remove the cam sprockets from the head being removed. The timing chain remains in the chain case.



Remove the timing chain guides. Access to the retaining screws is through the plugs at the front of the cylinder head.
Remove the water crossover.
Remove the left exhaust manifold. Refer to Exhaust Manifold Replacement.
Remove the right exhaust manifold. Refer to Exhaust Manifold Replacement.

Important
Do not reuse the head bolts after removal. New bolts have a special coating used for bolt retention after installation. This coating remains in the cylinder block threads after removal so proper cleaning of the cylinder block threads is important.


Remove and discard the cylinder head bolts.

Important
With the camshafts remaining in the cylinder head some valves will be open at all times. For this reason the cylinder head cannot rest on a flat surface with the cylinder face down, or valve damage will result.


Remove the cylinder head gasket.

Notice
Carefully clean the aluminum gasket surfaces in order to prevent damage to the sealing surfaces. Use only plastic, wood, or dull gasket scrapers, such as J 28410. Follow the manufacturer's recommendations to dissolve gasket materials with chemical agents.


Clean the gasket surfaces.
Clean the combustion chambers.
Clean the head bolt threads in the cylinder block with a soft brush or the equivalent.

Caution
Wear safety glasses in order to avoid eye damage.


Clean the head bolt bosses in the cylinder head with compressed air.

Time sert time lol....
requires kit a must.........

[mtflight]

and a tip, NEVER use a wire brush or Scotch Brite, when cleaning "with a brush" by soft brush they mean nylon or painting brush, etc.

[kreeger]

Thank you for all the feedback. I went out and bought a chevy colorado pickup with the new all aluminum vortec 5 cyl engine. This time I purchased the 100K warranty. And I will religously change out the coolant per manufacturer guidelines. I hope I don't get burned twice with a GM aluminum engine. This time around I will actively monitor for common problems and try to avoid them.

I will keep the cadillac and make it a long term project. Or i might try dump it off for $1000. It only had 100k so probably has alot of life left in it.

[kreeger]

I found this in an article:

DETROIT -- A number of components made from steel sheet, including a critical cylinder head gasket, are used in General Motors Corp.'s new Vortec 4200 Series inline six-cylinder engines for trucks.
The cylinder head gasket, which is one of several parts made from stainless steel, is a three-layered component that GM powertrain engineers said was designed for sealing durability. The coated gasket is expected to withstand more than 150,000 miles of operation in the vehicles in which the new engines are used, starting with GM's 2002 Chevrolet TrailBlazer, Oldsmobile Bravada and GMC Envoy sport utility vehicles.



I hope they are using this technology in the northstar engines too.