Joined Dec 24, 2004. My Car Shakes While Idling – What now? Add a comment . This is with AC and Heater off and no other heavy electric load. At 2500 rpm I have 9.6 volt etc. If it shakes while it idles, you could be in for a visit to the mechanic.When your car is functioning properly it should run smoothly in all driving modes – moving fast, slowly, stopped and idling. my foot is on the brake) the needle of the RPM Gauge bounces upward slightly, then immediately returns to normal. 110 1. 2001 dodge dakota 3.9l rough idle at start up rpms bounce around then engine dies, sag, and surge when in a pull like - Answered by a verified Dodge Mechanic. The rpms on my 2006 Dodge Dakota are jumping up while driving on the interstate. If you think that you have an issue with your A/C system but you are not sure which component is causing the malfunction it is a good idea to hook your compressor up to a pressure gauge.. An A/C System that is working properly should have 150 PSI on the high side and 30 PSI on the low side. I put in a new alternator, battery, and regulator. I also found that putting the car into neutral does not stop this; I have to throw the car into park. Now release the throttle and watch the gauge as the speed drops. I can build engines but I'm a wiring idiot. this also happens sometimes when i stop behind the red light. When the car is of I have 12.4 volts. gbp . my car has the same exact symtoms with the rpms moving up and down it only got worse finally i lost acceleration and the cause was a bad throttle body its an electronic part and i have 69000 miles on a 99 1.8t also i would check there just because its clean doesnt mean its working properly. The idle drops to 500 rpm when the AC compressor cuts off then bounce 1 time or 2 to get to 750. The RPM scale is what tells you how much your engine is running. Currently the engine starts and revs to 2000 rpm then will slowly start to drop to about 900 (the usual cold engine idle speed, no ac) It will hold steady there for a bit then start to bounce a little with an occasional drop to almost stall then a spike and a return to idle. So it's possible the PO replaced them but neglected to mention it. While sitting at a stop light, with the AC on, I noticed a groaning/rubbing sound coming from the engine compartment. Normally, a vehicle should have a smooth and consistent RPM rate of around 1,000. No tach bounce when cranking. They look to be in very good condition - no corrosion and solid, clean wires and connectors. AC compressor is a smaller engine in itself and puts a lot of stress on car’s engine. Garage keep atleast 50 degrees ... Could be a bad pulley on the AC compressor as it starts up causing more load on the engine. 2012 Ford Fusion groaning noise when defrost or AC on. but I don't think it is, so that means that the engine really isn't going faster. Run the engine at idle, low cruise (1800 to 2200 rpm) and high cruise (2500 to 3000 rpm). It's not dependent on RPM. After a few more stops I noticed that the sound was happening when the car was in gear and stopped (low RPM) and the AC fan was on 3 … The rpms bounce back and forth between 400 and just over 1000 rpm, it will continue doing this until I apply gas. Show 34 more comments. Note the vacuum readings, and any fluctuations, at each speed. DC controls adjust speed by varying the voltage sent to the motor (this differs from AC motor controls which adjust the line frequency to the motor). Cause: Defective bearing and/or pulley.. AC Compressor. My Accord is smooth. Then idled at the same 800rpm. It held the rpm solid. Anyway, I just noticed today that while my car is in drive, but stationary and idling (i.e. my car's rpm bounce when im at idle. We use cookies to give you the best possible experience on our website. when im at a stop light or parked, my 98 Honda Accord Rpm will automatically move up a little, like if im stepping on the gas pedal, which im not so it’s kinda weird, and when the rpm goes up, it makes my car move forward, so i have to step on the brake harder to keep it from moving. When the compression kicks in, the idle goes to 850 without dopping, likes it's supposed I think. the RPM is Okey when i “start” the car, however when i push the gas to start driving, the RPM goes up to 4k and 5k and the car does not run or runs supper slow (an RPM of 5k with a speed of 5MPH). As soon as I accelerated, it stopped. If your vehicle is falling below or rising above this you may be dealing with an idling issue. First, ignore my redness. I have a 2014 jeep patriot 2.4l and occasionaly on start up the rpm will bounce and the lights in the head lamp will flash then the jeep will settle down and idle fine . RPM s-p-i-k-ing/rough idle with A/C on? I have a 2006 Ford Taurus. I’m not 100% sure but the last two times, the AC was on/may have been just switched off (also the car is warmed up by this time). Drives ok and rpm are ok till about 10 miles then rpm jump to 7000 rpm and above. Moseley, Virginia. Swapped reference sensors. It's an automatic transmission and it does it when in P and D. Doesn't makes sens to me. I've noticed over the past few weeks that my '99 V6 idles a bit rough while the AC is on, as well as minor RPM s-p-i-k-es. 0 /1024. Next, hold engine speed steady at about 2500 rpm for 15 seconds and read the gauge. I am quite familiar with what the a/c compressor does to the engine idle. When I start the car, I have 11.5 volts at idle. lights flickering, gauges going wild, radio resets, ac loses powe 2005 town and country headlights flicker as well - Chrysler 2005 Town & Country question RPM Fluctuations And What They Mean The smaller parts of your vehicle might not seem like an issue, and most of the time, many people don’t even notice when an issue is present — but these small quirks might be the predecessor to a larger issue. if i am on the regular streets is normal.. does it when put it on drive and put the AC on.. the RPM starts to bounce does it when the car is on a stop light i have to hold the break down cuz the car would start to move forward with each jerk. Typical no load or synchronous speeds for an AC fractional horsepower motor are 1800 or 3600 rpm, and 1000-5000 rpm for DC fractional hp motors. I … It was idling at around 800rpm before the AC, turned on the AC and it flickered for half a second. Jan 26, 2005 #1. 10/12/2018 by Robbie Capps. So when you are driving, and the RPMs bounce like that, then the car SHOULD also move a little faster. 93ClipseVA Proven Member. Between 40-50mph the rmps will suddenly, intermittently bounce up and down about 100-200rmps for a short second. I have a 2012 Fusion and when the AC is on or defrost I get this groaning sound. Your car should run smoothly, whether moving or stopped. Cleaned the IAC. at first i thought it was just because it was cold, but it would still do this when its warmed up. Mine is a 1999 Honda Accord ex and when I push the brake the engine revs up to 1000 rpm and then drops down, it also makes a air leak sound when I press the brake petal.. the motor does have a air leak sounds coming from behind the head. with carburator cleaner and it done ok for about 35 miles then. When I let off the throttle and push in the clutch the RPMs bounce exactly one time to 1500 and then settles down to about 900 where it should be. Incidentally, both lifted right out, which leads me to believe they were replaced recently. Rpm Bounce At Idle Posted by 93ClipseVA, Jan 26, 2005. I recently had and issue come up with my rpms bouncing. My RPM arrow jumps up a bit when I have the car on Parked and turn on the AC. 0 items. Toyota just released an extension to the faulty fuel pumps that cause low rpm … When I kill it RPM stays locked on 5000- 6000 rpm. 1. It seems to make the rpms bounce. I … it does it when i am on the highway the whole car jerks with the rpms going up and down for a while then its normal . Also, I can feel a slight drop in power from 3500-4000 RPMs. I have a 2014 Rav4 and recently changed the Transmission. ... (6MT) rpms drop to 500, lots of vibration then they bounce back up. When I turn the AC off, the RPM revs slightly, then falls back into a smooth idle. I have a 67 Satalite with a 1972 480 horse 360. Hey guys! When you turn on the vehicle AC, engine triggers some … If the car starts to RPM higher than usual but the car hesitates, bucks, runs rough at idle or won't go and you have high RPMs… (1) I've always had noticeable bounce in my RPMs on my 09 Traverse LS when idling. The speedometer scale is tells you how much the vehicle is running when the engine is running. The bad guides allow the valve to move around a bit while the valves are at their lowest opening point, and the bad lobe will effectively kill that cylinder at low lift. Read on to learn a few of the reasons why your engine may have a rough idle, how to identify them and some simple fixes to try. RPM acting crazy. Sometimes continuously, other times, just a couple times. Hi, 2006 OBW 2.5: when ideling, and only when AC is ON, RPM goes up and down in a steady 3 sec rhythm. aed all amd ars aud awg azn bam bdt bgn bhd bmd bnd brl byr cad chf clp cny cop crc czk dkk dzd egp eur fjd gel hkd hrk huf idr ils inr isk jod jpy krw kwd kzt lbp lkr mad mur mvr mxn myr nok nzd omr pen php pkr pln qar ron rsd rub sar sek sgd thb tnd try ttd twd uah usd uyu vnd zar. Could this be a problem? Pulley bearing wear. understanding air conditioning gauges. As I rev the engine e I lose voltage. 2. When the rpms are at 700,( when AC is on ) it is smooth with zero vibrations. I have no engine mods and keep up with preventive maintenance. Appearance: With the engine off and the belt removed, manually rotate the pulley.If you notice noise, resistance or roughness, the problem is likely to be pulley bearing wear. The RPM fluctuates continuously by a few hundred RPM's. RPM jumped back up to 7000 and above . This is not that. It is dependent completely on whether or not you are able to feel it due to the truck being stopped or not. this is not happening when the AC is off. The more I accelerate the louder it gets. A vacuum gauge needle that vibrates rapidly at idle and then seems to smooth out with rpm can indicate bad valve guides or a bad cam lobe. It does this repeatedly jumping up to 1 and then going back to close to 0. 1500 rpm I have 10.4 volts. Be more concerned with your RPMs when driving the Traverse. Some dude with 170,000 rep power negged me from 62 green to -27,000. Then when I left for lunch I made sure I started the car and watched the rpm needle and to my suprise it does bounce and dip 200-300rpm when I first start the car. I turned on the AC this morning while stopped at light. , clean wires and connectors few hundred rpm 's recently changed the Transmission replaced recently they look to in... But it would still do this when its warmed up speed steady at about rpm! 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