OT MAF sensor on a 2001 Impala 3.8l

[Im Lon 2]

Can anyone help?

I have been having an issue with my car surging at 55-60 MPH when I would let off the Gas for the past month. Yesterday it started doing it at any speed and the check engine light finally came on so I could test out the Codes. The code came up as P0102. But when the guy was testing it he said it sounds like a vacuum leak.

So... Last night we took apart the Air Filter box, and the boot that connects the filter box to the Throttle body. The Sounds sounds like it is coming from inside the Throttle body itself. I have checked all the air lines and cannot find anything wrong with any of them. Does anyone know what this noise could be caused by? Maybe one of the hoses is clogged?

I do know that when you shut the car off, the sound keeps going for 5 sec's or so.


Any Suggestion would be appreciated

 

[DARKSILENTTYPE]

Replace the MAF . The noise you here is probably the A/C stabilizing

John

 

[Im Lon 2]

Thanks John.

Which sensor is the MAF? the one on the Boot? or the Throttle body?

One of the sensors and a Security Star nut that has to come out. Is that the one?

 

[DARKSILENTTYPE]

MAF = Mass Air Flow Sensor

Go buy on and you will see were it goes . Its the square piece with one connector at the end of the throttle body.

John

 

[scbadiver]

I agree with John. Go with a MAF sensor.

 

[Im Lon 2]

That is the one I thought it was. It is the one with the goofy screws I have to take out.

The Sensor in the boot is that an O2 censor?

 

[DARKSILENTTYPE]

know you have four sensor right there iac valve , maf, tps, and egr valve . Once you get the new MAF you will see were it goes no problem .

The one in the boot is the MAF

John

 

[Im Lon 2]

I was also told on a Car Forum that it could have something to due with the throttle sticking? One of the problems I noticed last night explains why when I step on the gas that it sticks (in the morning, or after the car has sat for a while.) When we had the Car apart last night we noticed that the throttle is gummed up in side the throttle body, causing the throttle to stick.

The car forum said that the MAF should be the last thing to replace because it is probably a problem before the MAF, but the MAF is catching the problem and sending a signal to the Engine light not necessarily it being the MAF itself even though it is what is throwing the code.

Before I spend 150. on a sensor (the size of a soda cap) I'm going to clean the Throttle body with some throttle body cleaner, then put everything back together and test it again. They also said to take the Throttle body cleaner and spray it around the air lines if the engines idol increases you can find the leak vacuum leak if there is one.

Not 2nd guessing you John. Just have been given so many try this try that. Right now I want to take the cheapest way first since I already have to clean the Throttle anyway before I put everything back together.

 

[Im Lon 2]

<a href=showthread.php?s=&postid=10013815#post10013815 target=_blank>Originally posted</a> by DARKSILENTTYPE
The noise you here is probably the A/C stabilizing

John

What do you meen by A/C ( not cold air A/C right)

I'm no good with cars, as you can tell. My head is spinning.:spin1: :fun5: :crazy1:

 

[DARKSILENTTYPE]

yes air conditioning . Try turning the car off after running it for a short time without the AC on and see if the noise is gone after shut off .

John

Not 2nd guessing you John. Just have been given so many try this try that. Right now I want to take the cheapest way first since I already have to clean the Throttle anyway before I put everything back together.

I understand trying to save money trust me .

 

[panaboy95]

try the choke spray. clean the throttle plate with choke spray and if you have an old baby bottle brush laying around use it to clean the plate. then when you are running it if you here a hissing and think it is a vacumn leak spray the choke spray around the area you will notice the cars rpm change. you have just found the vacumn leak. you should also clean the sensor. take it off. it is a tamper prof torx. get some electric cleaner and spray the little wires in the sensor. i also use a q-tip and clean them but be carefull the little wires break.

i really doubt it is the sensor. the sensor reads how much air the intake is getting. if the computer thinks it is getting more air than what the sensor reads (a vacumn leak) it will turn the check engine light on and think the maf is reading wrong.

another way to check a maf is just to tap on it. if it changes the way the car is running. it is probably bad.

 

[Im Lon 2]

Last night Rich and I took off the Throttle body, and replaced the Throttle Body gasket, cleaned out out the throttle body with Throttle body cleaner, and a tooth brush.. Looked like new when I put it back together. So far it sounds and seems to be running smooth.

 

[sirreal63]

You can't kill a 3.8 series II. It was one of the best engine designs ever made. Be careful to never touch the sensor wires on the maf, if you do clean them off with alcohol.

 

[Im Lon 2]

Okay Car seem to run fine for about 5 days after cleaning everything and replacing the seal to the throttle body.

My light for the MAF sensor is no longer on since then..

I do have another thought.

About a month ago before this problem started, I forgot my wallet at home and my fuel light came on, on the way to work. I had to drive all the way back home from work about 60 miles after the light came on. I wonder if the fuel filter could be clogged a little, causing not enough fuel, and then with to much air, if that could have set off the MAF sensor a week ago?

Any thoughts?

 

[capncapo]

I would think that if you're filter was clogged enough to make the sensor think that something was wrong that it should still be sensing the same problem. You haven't changed the filter so it should still be running lean if the filter is clogged.

Changing the fuel filter is something that you should do as a part of regular maintenance anyway so now might be a good time to do it.

 

[sirreal63]

The PCM for the 3.8 is a highly adaptive computer. It has built in fuel tables to account for that. The PCM will change fuel and timing curves based on what the MAF tells it. I looked into the programing of this PCM several years ago and it is a very sophisticated device. I would still change the filter, though it is probably a tank mounted filter and a pita to change.

 

[panaboy95]

the filters on those cars are pretty easy to do if you can get the car high enough at home. they have a screw in connection on one side and a quick disconect on the other. the new filter should come with the clip. i ussaly recomend replacement every year or 30k. a clogged fuel filter is the number one cause of fuel pump failure. and the pumps on those cars are a little high. not as bad as some though.

 

[rams]

how many times has stupid said it would be a lot easier if it was a hemi?

 

[Im Lon 2]

Replaced the MAF car run's fine.. Well almost have another problem now. when it rains it pours

Three days ago my car starting get a chirping sound.
Now, sometimes I get a No Noise at all, a Chirp, or even an Ear piercing Squeal. :eek1: It will do it when Idling or even accelerating down the road.

The Power steering was really low when I checked it Friday night, so I topped it off, Still get the same noise. So I'm not sure if that is the problem or not. Car Turns fine?

I have Read that it could be either the Power Steering or the Tensioner. Is there a way to check which of the two I should replace first? Belt was replaced back in Oct and has been very quite till now.

 

[sirreal63]

The power steering rack on front wheel drive GM cars has a history of going out. My old company car which was a Regal had two of them in a 100k miles. FWIW that is about a 2k dollar repair. Let's hope it is more simple than that.