20 Most Recent 1999 Buick Century Questions & Answers

nope you have to replace them.when brake booster diaphram leaks you cant plug them.i have bought one at salvage yard in good shape.until i got a new one.get your brake booster from inside salvage yard where they stock them inside out the weather.dont take any brake booster off old outside cars been in all kinds bad weather. there vacuum diaphram probably dried up will leak also.

1999 Buick... | Answered on Dec 01, 2019

HI. The cap will be 4 1/2 Quarts. That will include the filter as well.

1999 Buick... | Answered on Feb 21, 2019

most cars have it printed on decal the body under hood it will say 134-a capacity 2.3lb ,when adding Freon allways follow detailed instructions .if system has been emptied you may have to use Freon with oil in it

1999 Buick... | Answered on Feb 21, 2019

there is a light sensor locate up in defrost area of dash cover that controls the on and off of head lights

1999 Buick... | Answered on Oct 27, 2018

The fans should switch on automatically when the engine temperature reaches the prescribed temperature. Probably around 95C

1999 Buick... | Answered on Feb 27, 2018

Your high beam switch is bad most likely.

1999 Buick... | Answered on Feb 03, 2018

check for a vacuum leak.

1999 Buick... | Answered on Dec 18, 2017

Both radiator fan relay's ????? There are three relay's !
DTC P0481Cooling Fan Relay 2 Control Circuit
Circuit Description
Output Driver Modules (ODMs) are used by the PCM to turn on many of the current-driven devices that are needed to control various engine and Transaxle functions. Each ODM is capable of controlling up to 7 separate outputs by applying ground to the device which the PCM is commanding on. DTC P0481set indicates an improper voltage level has been detected, which controls the Cool Fan 2 and Cool Fan 3 Relays.

Check cooling fan maxifuse 15 amp. This fuse supply's B+ voltage too cool fan relay's 2 & 3 control side . The PCM supply's a ground to energize these two relay's , the PCM is not seeing the correct voltage that it should be . The fuse could be the problem , an open circuit , the transistor or driver as GM calls it output driver module . The number 1 relay is working fine , with A/C on # 1 relay is turned on or energized by the PCM for low speed operation .
There is a good video on youtube on how this three relay cooling fan system works an how to trouble shoot .
Relay Driven Dual Cooling Fan Diagnostics

1999 Buick... | Answered on Nov 03, 2017

Unfortunately, you've got serious problems. The GM 3.1 and 3.4 engines have a nasty habit of breaking camshafts. For some reason, which I have yet to determine, the cam bearings seize on the cam and the camshaft ends up breaking in half. The engine will continue to run, albeit very poorly since all the cylinders are not working because the rear half of the camshaft, which runs the oil pump, is not spinning.

1999 Buick... | Answered on Oct 28, 2017

With engine running what is voltage reading at the battery ?
Also a bad diode trio in the alternator will cause this problem if everything thing is charging ok

1999 Buick... | Answered on Oct 03, 2017

From what you said I would think you have a bad/loose connection. I have never had to change the fan resistor but from what I under stand usually when the resistor is bad the fan only run with the fan speed on the highest setting. If the fan quits working try putting the fan on the highest speed setting, see if fan starts working. Sorry but that all I got for now.

1999 Buick... | Answered on Sep 10, 2017

the inlet valve will be in line with the inlet port
the exhaust will be on line with an exhaust port

1999 Buick... | Answered on Sep 10, 2017

Most likely a bad wheel bearing, or wiring to the wheel bearing. I would start by having it scanned to point you in the right direction. (What bearing to look at). Could also be something in the ABS module.

1999 Buick... | Answered on Aug 15, 2017

Is the coolant full ? Any discoloring of the coolant ,look like muddy water ? gm dexcool antifreeze if mixed with regular green coolant can gum up the works , clog heater cores , radiators etc.... Have you ever had the thermostat changed , cooling system flushed ?

1999 Buick... | Answered on Jul 31, 2017

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