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Buick Century Custom Related Questions

Does the refrigerant in your Buick A/C need to be topped up? Need help to decipher fault codes on your Buick Century Custom? These are typical areas where users need help. A reliable source for assistance is a verified mechanical Expert.

Read on to learn how Experts have helped users by answering these and other Buick Century Custom related questions.

Can a Buick Century Custom engine be cranked without the ignition key?

No, this is quite impossible. The vehicle’s computer has an anti-theft feature which will shut down the fuel injectors when it senses an attempt to crank the engine without the key. There is no way to work around this safeguard.

Can A/C refrigerant be self-charged in a Buick Century Custom?

Yes, this is possible using a can of refrigerant available at most parts stores. Connect the can, in accordance with the instructions which come with it, to the low pressure port on the car system. Now turn the A/C on for about five minutes which should be sufficient to automatically complete the charging process. It is possible to overfill the system, but excess refrigerant will be released by the pressure port so no damage can be done.

What is fault code P0420 on a Buick Century Custom and how to overcome it?

P0420 is a fairly common fault code which indicates that the catalytic converter is failing. This impacts its ability to neutralize exhaust emissions as it should, which is detected by the car’s oxygen sensors. This fault code is set when the converter is deemed below threshold and due for replacement. Provided there are no leaks and misfires, the solution is to replace the cat converter. Avoid installing aftermarket converters because most are not up to standard and will not be capable of erasing this code.

Should the lower intake manifold gasket be replaced when there are no signs of oil leaks?

When the manifold gasket fails coolant could leak out onto the engine where it burns off, leaving no traces of leakage. However, a clear indication of leakage is a drop in coolant level, a red flag for gasket replacement. Avoid installing aftermarket gaskets and stick with factory original Buick Century Custom parts. The material in replacement gaskets has since improved to ensure better sealing and extended service. When replacing a manifold gasket be sure to replace the lower intake manifold bolts as well, and torque them in the recommended sequence.

When the head gasket and all hoses were recently replaced how could there be traces of oil in the coolant?

When replacing the head gasket the intake manifold gaskets should also have been replaced. This could be the source of oil in coolant or it could be oil residue left from before the gasket replacement. It would be advisable to drain all coolant, flush the cooling system and charge it with fresh coolant. If traces of oil still appear then further investigation is called for because, in the worst case, there could be a hairline crack in the block.

How to troubleshoot a starting problem on a Buick Century Custom when the engine is hot?

The ignition control module may have failed which is a known problem on this car. It may also be the PCM but a failed ignition module is more likely. If they are both OK then the starting problem could be due to a fuel pump relay issue.

What causes transmission shifting to become stiff when a Century Custom warms up?

Chances are that that the transmission pressure control solenoid and TCC solenoid are stuck in the open position. This is often caused by small particles of sediment or debris in the transmission fluid. Both can be cleaned by draining and flushing the transmission and replacing the fluid. If the problem persists both solenoids may need to be changed.

Many problems with a Buick Century Custom are outside the understanding of the average user. Consequently, an owner is driven to despair when the vehicle develops an issue. Fortunately, that’s the case; you can ask a verified mechanical Expert online. Experts will answer all questions concerning the Buick Century Custom. And all this can be done from the comfort of your home and at your convenience.

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