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Pontiac Grand Prix: Problems & Solutions
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sad mom....and even sadder son :lemon:
Not shifting into overdrive on the highway could be something as simple as low tranny fluid. Have you checked that? Must be checked with engine warm but not hot (about 20 minutes of light driving is good) and engine idling in park.
If you take it to a mechanic, they will hook it up to a OBD-II code scanner and find the system that is at fault for about $50. Then the fix itself could be something as cheap as spark plugs or as costly as EGR valve, etc.
If you are good with cars, certain auto parts stores will scan the code for free and you can look online to see what the code means, and attempt to fix it yourself.
Rob
Also consider the thermostat one last time. I've had one fail on me that was only a few months old.
At home, here are some things to try:
- As you try to start the car, does the tach show anything?
- Do you have spark on any cylinder? If you do, it's not the CPS. If no cylinder has spark, you still can't say it's definitely the CPS because it could be the ignition module or ECM. Maybe even ignition coils but it's very unlikely all 3 pairs of coils would go bad at once.
- If you don't have a scan tool but you have a scope or multimeter I think you can get a reading off the sensor wiring itself, BUT this is an undocumented way to test, so be careful. If you can probe the wires while someone else cranks I'd expect to see some kind of fast pulsing signal. Probably too fast for a multimeter.
I would have a friend drive beside you on each side, and behind you, on a bumpy road. He should watch to see if your wheels after hitting a bump, settle right down or if they continue to bounce a few times. Have him watch all four corners, one at a time as they hit a bump at speed, at least 25mph.
Bounces mean struts. On a 1996 it's a pretty easy job if you are mechanical. Try the test above and tell me what you learn. Also please share about any noises you hear when you hit the bump or afterwards.
Specs (just incase):
1998 Grand Prix SE
3.1 SFI Engine
175,000km (not sure how many miles that is)
thanks for reading, and thanks in advance for any information you guys can provide me with.
There has been a 89 3.1 Regal, 97 3.1 Century, 97 Cutlass Supreme 3.1, 95 Cutlass Supreme 3.1, and 02 3.4 Alero in my family. All these engines are close relatives of yours, with the 97s being practically twins.
The noise you hear is probably piston slap. It's a minor problem in these engines. My 95 3.1 has 152,000 MILES on it and ticks, but is running strong. Could be lifters too.
I would not worry about it. Use good oil, do NOT use oil treatments, and change the oil every 4-5k miles and you'll be fine. If I were you, depending on how much Lucas you put in, I'd dump it and start over.
If you want oil recommendations from me, tell me exactly where you live so I know the climate, and describe your typical drive (distance, speed, etc.).
If yes, it is likely to be piston slap. Quality oil will help. I suggest the Mobile 1 synthetic oil appropriate for your climate. I have a Sierra with 230,000 miles and a Grand Prix with 172,000 miles with strong engines and no piston slap. Never had internal problems on either. The secret is using synthetic oil and regular maintenance for the life of the engine.
If no, it may be in the transmission which would cause the sound to appear in the bottom end of the motor if front wheel drive. Try a power flush and filter change on the transmission. When the oil heats up it flows easier around metal shavings that may be blocking the pick up and circulation points.
for the oil information, I live in southern canada so its still bloody cold (well below freezing 10-20 fareinheit) in the winter and pretty warm in the summer (reaching 90-95 fareinheit. I live in a small town (very rarely city driven) and drive approx 40km (25miles i think?) to work.
I did just do an oil change on this car and probably won't bother again untill my 4-5,000km are up. but thanks alot guys it seems everything is pointing towards this piston slap, just the way it acts. by the time i am home from work its running perfect. I was lead to believe that a lazy lifter or lifter troubles wouldn't go away when the car warms up.
Sometimes very light, sometimes it goes on for a minute or two.
Momwag, is your Grand Prix a 3.8 or 3.1? The 3.8s aren't as prone to this.
Momwag is right about using the right oil.
Southern Ontario isn't too different than my northern Ohio climate. If you can find Mobil 1 0W-40 I have had excellent results with it. Sometimes you gotta look around to find a store that sells it. It flows fast at cold temperatures and startup, yet stays slightly thicker at high temps than a 5W-30.
If you just can't find 0W-40, go with Mobil 1 5W-30 in the winter, and in the summer 5W-30 but blend in 1/2 to 1 quart of the 15W-50 they have.
Your mileage isn't extremely high but it's hardly a tight new engine either. Remember, when GM spec'd 5W-30 for your engine, they had dino oil in mind. A synthetic of the same "rating" will flow much better when you look at detailed manufacturer specs.
As far as fixing it mechanically, I have no experience, but in all the online communities I participate in I haven't heard of anyone do it. Possible sure, but probably ridiculously expensive.
Just remember that for the most part this is a benign noise you are hearing and good oil will keep the car running for many miles to come.
Is the fuel pressure gauge showing roughly 40psi both when you turn the ignition to "ON" and when you try to start the car? It shouldn't change much as you're cranking away, have a friend watch it for you as you try that.
If you have good pressure, I would lean towards fuel injectors having gone bad. They are the last stop on the fuel's trip into the engine, more or less.
But before you diagnose those, I would make sure you have good spark. Buy a spark tester and check at the front ignition wires that are convenient (one or two is fine). If you find spark (and I bet you will) then it's time to Ohm test the injectors... on that car I think you'd have to take the upper intake off to do so. You basically unclip each injector's wiring connector and check OHMS. You may find from 1 to a few of them deviating from the rest. Off the top of my head I can't remember the correct resistance but for some reason "12" is stuck in my head.... I will have to dig that up if you need it. Usually what I do is test all 6 and the 1 or 2 that are the most abnormal get replaced.
If you use a high detergency gasoline on a regular basis, that will cut down on the need for cleaners. Do a google on "top tier gasoline" to learn more.
As far as professional fuel injector cleaning, it's not a bad idea, but GM injectors do fail electrically. It's common after 100k miles. So it's a better long term investment to replace them with new ones if you plan on keeping the car a while.
This is the only piece that lost illumination? Maybe it was coincidence that it went out from the crash.
i have had overdrive replaced but my car still clunk's when trying to go into the gear.
my Torque converter has been replaced as well as the solenoids. the service engine light is still on. the computer says its still my converter.
my windshield wiper fluid will not come out
my gas mileage is ridiculous and i have spent over 3,000 and still have not solved any of my problems
anyone have any ideas or suggestions?????
my key keeps getting stuck in my igntion. the car will not shut completely off when this happens. im afraid that if i don't figure out the problem soon that one of these times it is going to get stuck for good!!
any ideas or suggestions???
thankyou!!">
As far as the windshield washer, have you checked that the pump is definitely not getting power using a multimeter or test light? You could also jumper the washer pump to +12V on the battery and see if it starts pumping.
Unless people stand up to shady businesses (in any sector) they won't go away.
As far as the washer: when you apply the washer, do you hear the whirring sound it normally would make? If so - look for a disconnected hose under the hood or at the wiper arms. If not - check your fuses, and if you're able to, check whether power is getting to the washer motor.
Hope this helps
For the price you can buy a much better car!!!
hole so it keeps the button pushed all the time.
Heads up! keep an eye out for some "shift lock release" problems in the future.
Hope this helps anyone with stalling issues. Thanks for all of the help you all have given me.