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#192 of 361 1998 Grand Prix SE 3.1 Questions.
Oct 06, 2009 (10:20 pm)
Hello everyone. First off, thanks for taking the time to read my post.
I have recently bought a 1998 Pontiac Grand Prix SE 3.1 for $600.
When I purchased it, it had the Low Coolant light on, and check engine light on.
I knew right off the go what the coolant light was. Damage to the intake manifold gasket due to the DexCool that was in the cooling system. I had that replaced. The Low Coolant light is still blinking, I'm thinking it is a bad sensor because I had also just replaced the radiator cap and upper hose, no further leaks are found in a pressure test. Oil was changed when intake was replaced as to get out all the coolant/water from the engine oil. This is not my main problem.
The main problem is the car has a somewhat of a rough idle. More now than before.When you start the car (It starts fine by the way) the RPMs fluctuate from 500 RPM - 1000 RPM. It doesn't die out, but sounds sluggish. It is fine while moving, and when it slows back down to idle, it fluctuates only minorly.
The Check Engine light I am getting is for a Camshaft Positioning Sensor.
I know where it is, and how to change it. But, would this be the reason of why it is acting so strangely?
#193 of 361 Re: 1998 Grand Prix SE 3.1 Questions. [esone]
Oct 09, 2009 (1:02 pm)
Hello, well if you currently being advised that the camshaft positioning sensor needs replacing: this may solve your problem but if it continues then you will more than likely need to replace the crankshaft positioning sensor also since they both work in conjunction with each other. If you get a automotive manuel for this you will find and read about the " Hall Effect ".... Good Luck with your new toy! smv1
#194 of 361 Still not working...
Oct 12, 2009 (4:13 pm)
I had my 2002 grand prix at a local mechanic with stalling issues. Sometimes it would start, and stalls near idle, but has also stalled while driving. He initially fixed some vacuum seal and that didn't do the trick. He replaced the crankshaft position sensor and that didn't work either. I took it to a dealership where they put in a new PCM and ignition control module, not a damn thing. The service engine light just came on (after all of this work) and it's reading P0300, multiple random misfires, and i have no idea what the problem is. It will start and run beautifully sometimes, other times it takes multiple attempts to stay running (will turn over, quickly die), and often it will run very rough and will "rev" for no reason. Anyone!?
#195 of 361 Re: Still not working... [jessewoo15]
Oct 12, 2009 (7:48 pm)
I wrote earlier that I solved my problem (all the same symptoms) by just cleaning up the battery ground cable. It cost next to nothing if you or a friend can do that yourselves. Check for voltage drop or whether there is any resistance between the battery negative terminal and a good ground spot on the engine. I did not spend a single penny on replacing any of the components mentioned. It worked for me. It may not work in your case but it is worth a try. Please let us know the results if you do that.
#196 of 361 At A Loss With Similar Issues
Oct 13, 2009 (1:23 pm)
I have a '99 Grand Prix GTP with about 65K on it. Car never had any problems until recently, and I'll explain: I purchased gas at a diff gas station than I normally do (I try to stay with one particular "brand"), got the premium as always, no issues. After getting home and trying to start the car back up again it kept sputtering when I accelerated, and died out when at a complete stop. The car will start back up again, no problem. If I get the car to maintain a certain speed (highway driving, for example) I have no issue with stalling or sputtering when accelerating. It seems to happen if I am: A) at a complete stop - it will sputter, jerk forward, then sometimes die out (not always though). B )if I am starting to accelerate after a stop/starting up the car will start to sputter. If I let it run idle the car will sputter, and the lights will dim as well with each sputter, as well as the RPM gauge moving up with each sputter. I have already changed my fuel filter, and I had added some Lucas fuel additive in case it was bad gas. Is that a possibility? I still have not run all of this gas out of my tank (I got a full tank) I also had taken the car to both Autozone and Advanced Auto Parts for the free diagnostic check and neither place showed my car as to having any codes to figure out what the problem could be. (also there is no Check Engine Light on). I don't have a lot of money (paycheck to paycheck living here lol), and since no codes/engine light are coming up then what could the issue be? Any help would be appreciated, thank you so much!!
#197 of 361 Re: At A Loss With Similar Issues [severedstar]
Oct 13, 2009 (1:39 pm)
I had similiar problems, car would start then stall, idle would bounce around. The problem is your fuel injectors and body is dirty and you need it professionally cleaned by a pontiac dealer. It's called a BJ Fuel inject and they take off the cover and clean all of the injectors and body. It costs about $100 but well worth the money as I immediatly saw a jump in my MPG's. Used to be around 19-20, now I'm around 23-25. The cleaning will pay for itself in no time. I made no other changes at the same time and this immediatly solved my problem. I did change the oil & filter, fuel filter, and air filter about a month after just to make sure my car had everything it needed to last. You have to remember that the oil is the blood of your car, the engine is the heart, the air filter your lungs, collant is your clothes to keep you at the correct temp, and the gas is your food (fuel). If any of these gets clogged up you are going to have problems. You should always check each of these things everytime you get an oil change done to make sure there is no problems (except fuel filter as that can wait 4 or more oil changes).
#198 of 361 Re: At A Loss With Similar Issues [severedstar]
Oct 13, 2009 (1:40 pm)
I've been there: I really hoped at first that my car's issue was that one day I had simply gotten gas at a cheapie place. $811 in repairs later, I'm sad to say that it wasn't.
However, I'll also say: The guys at the garage NEVER had a problem with the car.
For them, it always ran great.
For me, it often refused to start or just died in the middle of traffic.
The car runs fine now, but I feel some loss in power -- as if the V6 has gone down to a fully functioning 4-cylinder.
#199 of 361 Re: Still not working... [pat_from_grove]
Oct 13, 2009 (4:25 pm)
thank you for your response. I did indeed try that fix. I used a wire brush to clean up the terminal, the screw, and the frame of the car where they all bolt together. I was initially encouraged because my car started quicker than I'm accustomed to, however it faded within minutes as the car stalled while idling. I spoke with the dealer again today who had been working on it. They test drove it last week with an Ignition Control Module (factory) from a spare engine they had in the shop and they said it never gave them a single problem. After installing my aftermarket part ("standard" brand) it didn't give me any problems after 3 short trips but sure enough, it stalled out again. This is the first time the CEL came on too, code P0300 (random multiple misfires), and the engine was oddly "revving" after a cold start, it would run rough too. They're going to put their ICM back in and let me test drive it for a few days, assuming it doesn't give them any problems. I'll keep my fingers crossed.
#200 of 361 Re: Failing to start/ studdering then stalling [rjp81489]
Oct 14, 2009 (10:02 am)
If your friend believes that you are getting a fuel cut; then I would suggest that you check your fuel preasure with a gauge. the guage will cost $35.00 to $45.00. If you do have low preasure, I would estimate that a new fuel pump will be aprox - $300.00 ..... Good luck and please post your result's....Sergio.
#201 of 361 Re: At A Loss With Similar Issues [05grandprix]
Oct 14, 2009 (11:25 am)
Actually last night on my way home from work on the highway at 60MPH it decided to die out, I was able to get on the shoulder, kick it in neutral, and crank it back up with no problem. That was when my Check Engine Light FINALLY came on. A blessing in disguise! I took it to autozone, a code came up for bad/defective MAF sensor. The ACDelco MAF sensor is around 300, the Cordone brand is 150. Do I really need the ACDelco MAF sensor? I am also going to buy an air filter no worries there. But its double the price of the off-brand, and I know ACDelco is GM made but I don't really have that kind of money to spend right now and I need the car to run smoothly so I don't end up sh*tting bricks on the highway again LOL. By the way 05grandprix, I get 25 MPG right now, but then again I do a lot of highway driving (50+ miles daily). I had my oil changed in Sept, and I get it changed religiously along with checking coolant/power steering fluid levels etc. Ive had the car for 6 years and Ive put 15-20K on it, it's only been the last few months with my new job downtown that I've had to drive so much, but I would still change my oil and everything accordingly. Thank you for your advice everyone!!! I just need to know now if I really do need the ACDelco MAF sensor or if the off-brand is just as good due to $ issues. Thank you!