Page 1 of 2 12 LastLast
Results 1 to 10 of 20

Thread: RPM not super steady?

  1. #1
    Senior Member Getting Dirty superacerc's Avatar
    Join Date
    Sep 2010
    Posts
    801
    Rep Power
    14

    RPM not super steady?

    Here's a question I'll put to the forum. The XK has never really idled very steadily. Most of the time its not bad but sometimes hunts around a little bit. Anyone else ever have this issue? It doesn't cause any problems and it's not drastic by any means but the lights will dim a little cause it'll idle really low and waiver around. It almost seems like it's too low in general.
    Ideas?

    P.S. I feel almost guilty for the amount of time i've been looking at the Subaru forum for my forester. I'm not used to having so many options on everything!! I can read for hours.
    2007 Commander 4.7L, QTII, OEM Towing Option, tow hooks, 2"OME + 1/4" rusty's leveling spacer, Bilstein 5150 Rear Shks, Rear sway bar removed, 4xguard front skid, Offroad Unlimited Defender Roof Rack, Hella 500FF lights, 265/70/R17 BFG KM2 M/Ts 1.5" Rough Country Wheel Spacers
    http://www.theultimatejeep.com/showt...acerc-s-Garage

  2. #2
    Junior Member Looking for Dirt
    Join Date
    Jul 2011
    Location
    Houston, TX
    Posts
    24
    Rep Power
    0
    I have the 4.7l as well and have always had a very steady idle. In fact, when I first bought it there were times sitting at a stop light that I could barely tell the engine was running.

    I only notice the slight fluctuation in RPMs when the AC compressor kicks on and off. Have you tried cleaning the IAC valve to see if that has any affect?
    2006 Jeep Commander, 4.7L, QT2, Dark Khaki. Rocky Road lift in front (w/bilstein struts), Old Man Emu HD springs in rear (w/Old Man Emu shocks), Goodyear Duratrac 265/70's on stock rims, AFE CAI, all mopar skids. 4xguard front guard, belly guard, rock rails, and rear sliders.

  3. #3
    Lifetime Member Getting Dirty strokeZ's Avatar
    Join Date
    Aug 2010
    Location
    Houston, TX
    Posts
    344
    Rep Power
    14
    Every once in a while it wandered a bit - but rarely happens after I installed the Jet Stage 1 Chip.
    2012 Jeep JKU Rubicon - 4-1/2" AEV lift w 35" Toyo's

    03 BMW Z4 2.5i ESS Stage 2 Supercharged, Custom Suspension, Stebro Exhaust, Hamann Side Skirts

    85 BMW 535is Lowering springs, bilstein sport shocks, extra attitude

  4. #4
    Senior Member Getting Dirty superacerc's Avatar
    Join Date
    Sep 2010
    Posts
    801
    Rep Power
    14
    It does it with the air off or on. It's definitely not from the A/C. It's just a random fluctuation. Almost feels like it wants to shut off on very rare occasions. It's always done this (or at least since i've been in houston).
    2007 Commander 4.7L, QTII, OEM Towing Option, tow hooks, 2"OME + 1/4" rusty's leveling spacer, Bilstein 5150 Rear Shks, Rear sway bar removed, 4xguard front skid, Offroad Unlimited Defender Roof Rack, Hella 500FF lights, 265/70/R17 BFG KM2 M/Ts 1.5" Rough Country Wheel Spacers
    http://www.theultimatejeep.com/showt...acerc-s-Garage

  5. #5
    Lifetime Member Getting Dirty Matt's Avatar
    Join Date
    Feb 2011
    Posts
    7,771
    Rep Power
    22
    2007 4.7L uses an IAC right? Might want to try cleaning the valve to see if that smoothes it out (or just replace it depending how many miles you have)

  6. #6
    Senior Member Getting Dirty criket's Avatar
    Join Date
    May 2011
    Location
    Dobson, NC
    Posts
    647
    Rep Power
    13
    Long shot but maybe it could be the oil pump? Do you have an oil pressure gauge on your dash? Reason I say oil pump is this past weekend, I was driving my brother in law's chevy truck and at the stop lights, the oil pressure would drop and it would almost stutter out. I put it in Nuetral and rev the motor a bit and it was fine. It didnt' do it constantly but it happened a few times.
    SOLD - 2005 | WK | Khaki | 3.7 | QT1 | OME HD Front Struts | Rusty's 2" lift in Rear w/ Monroe load levelers (F150 version) | 265/70 Nitto Terra Grapplers | 17" Moabs | 1.5" wheel spacers | Pinch weld mod | Rear fender trim mod | 4xG Matrix w/ reciever hitch | 4xG Belly guard | SOLID Diff cover | Cobra CB radio | 4xG CB radio antenna mount

  7. #7
    Junior Member Looking for Dirt
    Join Date
    Jul 2011
    Location
    Houston, TX
    Posts
    24
    Rep Power
    0
    Quote Originally Posted by Aggie07 View Post
    I only notice the slight fluctuation in RPMs when the AC compressor kicks on and off. Have you tried cleaning the IAC valve to see if that has any affect?
    Sorry, I was not implying that your A/C could be the issue. I was simply stating that is about the only time my RPMs fluctuate, which is normal.

    My suggestion was to clean your IAC valve, or like Matt said, get a new one if you have high mileage already.
    2006 Jeep Commander, 4.7L, QT2, Dark Khaki. Rocky Road lift in front (w/bilstein struts), Old Man Emu HD springs in rear (w/Old Man Emu shocks), Goodyear Duratrac 265/70's on stock rims, AFE CAI, all mopar skids. 4xguard front guard, belly guard, rock rails, and rear sliders.

  8. #8
    Lifetime Member Getting Dirty Matt's Avatar
    Join Date
    Feb 2011
    Posts
    7,771
    Rep Power
    22
    Loss of oil pressure is due to a loss of RPM, not the other way around. Mechanical pumps depend on engine RPM to pick up the oil.... so if the engine starts to stall for some reason you will lose oil pressure.

  9. #9
    Senior Member Getting Dirty superacerc's Avatar
    Join Date
    Sep 2010
    Posts
    801
    Rep Power
    14
    Sorry bout that. I saw a bunch of A's and C's together and missed IAC. I've never cleaned one before. Any tips? I take it it's on the throttle body.
    2007 Commander 4.7L, QTII, OEM Towing Option, tow hooks, 2"OME + 1/4" rusty's leveling spacer, Bilstein 5150 Rear Shks, Rear sway bar removed, 4xguard front skid, Offroad Unlimited Defender Roof Rack, Hella 500FF lights, 265/70/R17 BFG KM2 M/Ts 1.5" Rough Country Wheel Spacers
    http://www.theultimatejeep.com/showt...acerc-s-Garage

  10. #10
    Lifetime Member Getting Dirty Matt's Avatar
    Join Date
    Feb 2011
    Posts
    7,771
    Rep Power
    22
    yup. easiest thing to do it look up your IAC on a parts website so you can see a picture of it (if you dont know what it looks like)... they're normally very easy to get to.

    To clean it you can fill the ports up with carb cleaner/gum cutter/etc... let it sit for ~15 minutes.... dump it out... refill and let it sit for another 5-10 minutes.... then spray the hell out of it.... let it dry and reinstall. Sometimes this work and clears up the issues for a long time, other times it works for just a few days and the symptoms come back (in which case you'd just order a new one).

Page 1 of 2 12 LastLast

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Super Sliders
    By Knappster in forum The Steel Armadillo
    Replies: 246
    Last Post: 04-26-2013, 10:36 AM
  2. Benelli M1 Super 90 Shotgun
    By Knappster in forum Guns / Firearms Discussion
    Replies: 2
    Last Post: 11-25-2010, 10:47 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •