something wrong with my car, RPM issues

Discussion in 'The Garage' started by mozirry, Apr 3, 2009.

  1. mozirry

    mozirry Senior member

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    I think my car has way too high of a idle RPM,

    I've been trying to figure out why my MPG have been so awful lately (I have a 96 saturn that rough starts every morning), and I think it may be a more serious issue then a dirty fuel injector.

    When I start the car in the morning, I have to rev the engine up to over 2000RPM for a few seconds before it will start to idle on its own. It's fine while driving, stopped, re-starting, but the process has to start over again if I leave the car unused for over 8 hours.


    Basically, when I am at a dead stop, I RPM at around 1000-1200 RPM. When I let my foot off the brake without touching the gas peddle, it revs up to 1500 and I can cruise at 30 mph on flat roads without even touching the gas peddle.

    Pushing the brake I always thought was just bad brakes, now it feels like I'm trying to stop a car that has a foot on the accelerator.



    125,000 miles
    96 saturn sl2
    -------------------------


    How serious/not serious does this sound and what type of problems could be underfoot?
     
  2. Vette73

    Vette73 Lifer

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    Is the engine light on?

    Remove the idle air valve and clean it well. Then spray carb cleaner into the hole it came out of. Reinstall and see what happens.

    Also the PCV valve on the top of the motor, look at the hose that connects it to the intake. Is it cracked/leaking? It would be bad on the bottom so you need to remove it to check it out.
     
  3. boomerang

    boomerang Lifer

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    There's a sticky thread at the top of this Forum that asks for Year, Make, Model and Mileage. We know it's a 96 Saturn but that's about all so far.

    There was a thread here within the last month with hard starting problems. There was some discussion and it appears that the Saturn model in that thread was notorious for coolant temperature sensor problems.

    Here's the thread. http://forums.anandtech.com/me...284861&highlight_key=y The OP never responded back with the results.

    I think you've got more problems than that. I'd be looking to make sure the throttle body is not coked up and not allowing the throttle plate to fully close. This could explain your high idle and resultant stopping problems.

    Read that thread through. There were some links to Saturn forums. There was mention of other sensors that are problem children.
     
  4. Vette73

    Vette73 Lifer

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    ^

    I am usually pretty anal about drilling that into people but in 1996 there was only 1 motor for a Saturn and that was the 1.9L. It came in either a Sohc or Dohc setup. The L series did not start until 2000.

    So he has a S series Saturn with a 1.9L, with either a DOHC motor or SOHC.
     
  5. boomerang

    boomerang Lifer

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    Oh OK, I'm not that much of a car guy anymore. I didn't know. :)
     
  6. nerp

    nerp Diamond Member

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    02 sensor maybe?
     
  7. mozirry

    mozirry Senior member

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    Hopefully it's not expensive whatever it is heheh, but nevertheless, car gets me to work which is all I use it for
     
  8. EightySix Four

    EightySix Four Diamond Member

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    Check your air filter.
     
  9. mozirry

    mozirry Senior member

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    update, trying to drive the car is much much worse, to the point that I could barely get it to idle w/out stalling while going to walmart + getting gas today. Pretty embarrassing lol, but I was able to get it back home.

    =(

    I will do one last run through standard checkups in case I missed anything (fluid levels, air filter, battery) but right now my car is not driveable.

    Basically it took a nosedive over a span of 2-3 weeks. I will take my car in to my mechanic and just leave it there and see if I can get an estimate, if it's too much, I'm not sure what I'm going to do.... I have a secondary vehicle that works great, but eats up gas like a hog.

    Either way, the saturn's gas MPG took a nosedive as well, it get 18mpg city when I filled up today
     
  10. mozirry

    mozirry Senior member

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  11. arrfep

    arrfep Platinum Member

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    Have you changed the ECTS (Engine Coolant Temperature Sensor)? Saturns of that vintage are notorious for that sensor being problematic. It's made of resin, and eventually corrodes/cracks in the hot coolant. You can pick up a new brass one at Autozone for under $10. Changing it will fix a myriad of problems.

    I've got a 95 SW2 that recently had very similar problems. I changed the ECTS and pulled the EGR valve off and scrubbed the hell out of it. It was caked over with carbon deposits, and barely opened and closed. I also cleaned the throttle body which was also gunked up with carbon buildup.

    One of these three repairs, or the combination of all three, did the trick. I went from not being able to start the car when it was warm, having a very rough/high idle to a strong start every time and a very smooth idle. Throttle response is also much better.

    Give all three fixes a shot. There's tons of tutorials online and you can do all three (even change your PCV valve) for under $20. PM me if you need some tips.

    Edit: Just an FYI, I read your later posts and see you were getting bad gas mileage. I was dealing with that too, around 17mpg if I was lucky. I'm still on my first full tank after the repairs, but I'm on pace to hit probably 24-25mpg now. Still a little low, but I've got more work to do.
     
  12. Zenmervolt

    Zenmervolt Supermoderator<br>The Garage<br>Elite member

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    This post has some very good advice. I believe that the items in this post would solve the issues that the OP is having. Good job.

    ZV
     
  13. heymrdj

    heymrdj Diamond Member

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    Definitely check out that ECTS. It controls how the PCM feeds the motor to a good extent and can cause alot of issues for such a cheap part.
     
  14. mozirry

    mozirry Senior member

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    thanks! Since this is a relatively new car for me, I don't have a haynes/chiltons manual for it yet but I'm going to go grab one to see if I can locate these parts and see if I have the tools/knowhow to resolve them. My only engine bay room work is replacing spark plugs/filters.



    Here are some updates today I opened up the hood and w/ a flashlight looked around at the engine while I saw it idling.

    I noticed that the fan in the radiator is not moving, and I also notice that a 12-15 inch rubber hose going from intake air to area near the spark plugs on the engine block is very corroded/cracked, but does not appear to be leaking air.


    Thanks again for the posts, hopefully I can find this!
     
  15. MikeMike

    MikeMike Lifer

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    your radiator fans will kick on/off when they need to.. they wont always be on, nor will they always be off...

    perhaps change the intake hose?

    those model years saturns are almost bullet proof, but they will burn oil at some point... so keep up on the oil
     
  16. mozirry

    mozirry Senior member

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