Hum/noise on driver's side dash

SOURCE: buick lesabre nightmare 2

• The PCM doesn't even see the O2 sensor until engine temp has reached operating temp,the vehicle goes from open loop when cold,to closed loop when warm,where the PCM uses the O2 sensor to measure the rich/lean of the exhaust content,and from that,adjust fuel richness to achieve 14.7 to 1 air/fuel ratio.So when cold,the O2 sensor is out of the picture anyways.When unplugging sensors,it can be deceitful.The PCM has a program whereas,if a critical sensor (such as the mass air flow) is somehow damaged and out of the picture,the PCM will substitue a generic value that will allow the engine to stay running.So,by unplugging the MAF,it did try to run on it's own better than plugged in,there's the problem area.The vehicle is running better with the MAF unplugged,because the MAF is likely bad,and the PCM is substituting it's generic value when it IS unplugged.Something to recheckThe PROM update is a newer program for the PCM,and likely won't fix it unless the PCM is bad.I would try a good used PCM as a last or later resort,because i have seen my fair share of defective PCM's too.I have taken some PCM's apart,and found capacitors that had gone bad and leaked all over the circuit board,mostly Honda and Mitsubishi and Chrysler though.Good luck,keep me posted.

ZappaNut

• 960 Answers
• Posted on Nov 18, 2008

SOURCE: location of air ride pump

it should be right under the hood (follow the small air lines to it)
If it is not there , then they hide them under the rear quarter panel on some models.
Follow the lines from the shocks to it .

SOURCE: Replacing spark plug wires on 1995 Buick Riviera

You need to drain some coolant. Loosen and disconnect water lines by the firewall- the ones in the way of your wire change. u need to get a diagram of the firing order of the engine so that those wires are correctly connected to the coil packs.

SOURCE: 92 Buick Le Sabre engine stumbling/hesitation

Have you checked fuel pressure? How about spark on all 6 cylinders? Maybe a coil?

SOURCE: Have a leak under passenger side dash when it rains. I think the door under the cabin air filter isnt closing is it an easy fix

Having just repaired this problem in a 1998 Buick Regal, I can tell you that fixing the water leak is actually quite easy. It took me quite a while to track down the source of water, but I have discovered that it comes through the cabin air filter. There is a seal on the passenger side of the cowl (A two piece unit, black plastic, against the windshield) that seals it to the windshield to prevent water infiltration. It is very small and somewhat hard to miss. I took the cowl off to change the filter when I discovered this.

You can make a diverter to go over the air filter under the cowl, or even easier is to use some clear RTV silicone (avalible at any automotive and most hardware stores) and put a good bead on the old seal. When you re-install the plastic cowl, be carefull where it goes against the windshield to make sure you don't "smear" the silicone. After you re-install the plastic retainer hardware, smooth out the bead and clean up the excess silicone(a wet finger and some old cardboard works great). Let it dry and clean up the water in the passenger compartment.

Cleaning up the water is the hard part. Removing the plastic trim around the door (if you grasp the trip peices firmly they just pull up off some metal clips,but they can be quite stubborn) you will notice the carpet just pulls up. At the bottom front corner of the front doors the carpet has a plastic hook that is around one of the trim clips. Lift it off that and the rest of the carpet towards the firewall just pulls up. If it has been a long problem, your carpet may be moldy. Also, the carpet edges and some of the more hidden panel clips are very sharp and may cut you while you are poking around, so be carefull.

Since the water entered through the air filter and right over the fan, you will at minimum want to replace the filter. I had mold and moss growing on mine. My fan also squeels and chirps now, so I know it got wet. Not much to do about that but replace it or carefully lubricate the motor.

In your question you mentioned a door underneath the filter not closing. On my '98 Buick Regal there is no door or valve of any sort. The filter sits right above the fan blades. It is the cowel's job to prevent water from entering this part of the vehicle. I hope this helps you fix your problem.