20 Most Recent 2004 GMC Envoy - Page 8 Questions & Answers

The valve body has failed inside the transmission. . It's possible the shift solenoids or the transmission control module are faulty as well.

If there is an OD button on the gear shifter or has two drive ranges on the shifter then yes

Sensors for the engine control module or the module itself change timing . If something goes wrong, the module goes into what's called the limp in mode. It keeps the engine running so you're not stranded. It only allows limited driveability, just enough to get you home or to a repair shop.

Mass airflow meter is faulty

The pulley has a bearing in it that needs to be replaced. Special tools are needed to take the clutch plate off to release the snap ring holding the pulley on the compressor.

There is a solenoid that opens the freon flow into the back evaporator. It isn't working correctly.

The moisture drain for the air conditioner is there. When it plugs up, excessive humidity removed by the A/C will leak out onto the floor board.

Internal governor, low hydraulic pressure, bad vacuum modulator. A transmission overhaul will fix it.

vacuum

Lots of things can cause this. A circuit breaker(not a fuse) could be open, the seat control switches may have failed. The seat rails may need lubrication, the motors may be bound, the body control module may have failed. Test all of the above and you will find it.

There are rubber suspension parts that may be worn . I would inspect the entire suspension for worn parts.

That means the air has left the shocks. The compressor may have a bad fuse or have stopped working all together. The level sensor may not be operating either. .

You have to take the wheel bearing nut off the axle and pull the bearings with it.

You can't adjust the codes. When the cruise control is working properly again, the engine light will stay out once it is reset.

Look on the underside of the relay box cover. If it only has numbers, look in your owners manual for the identification .

Its inside the connection where the suction hose connects to the evaporator. You must release all the freon out before you open the hose or you'll get a face full of compressor oil.

On the Mass airflow meter where the big air inlet hose from the air filter connects to the engine The throttle linkage operates it.

Junk yard

Automatic idle module isn't working. Isolating the knock is going to be more difficult. There are many reasons an engine knock develops. It will take a good mechanic to tell for sure.

Look on the intake manifold. There is a raised # 1 usually on the left front of the engine.