Question about 2008 Jeep Cherokee Grand

Open Question

08 Grand Cherokee, high idle (1500) on start

Every single time idles high regardless of outside temp or the temp of the engine. I could drive 50 miles turn it off and restart it immediately and idles fast. tranny jerks into reverse sometimes going to drive. I cleand the air sensor and the airflap on the other side of the air intake canister

Posted by on

6 Suggested Answers

  • 1 Answer

SOURCE: Heater blows cold air when idle

Sounds like you may have a partially plugged heater core. You could flush this out separately, from flushing radiator & engine block. Diconnect heater hoses going to your heater core and clamp off, so not to loose coolant from engine. Now hook up separate hose to one side of heater core pipe and flush out with typical garden hose. Repeat procedure on both heater core inlets. Reconnect original heater hoses and test difference. You may have to add an additional litre of antifreeze. If this don't work i suggest changing heater core. Good luck.........Ron.

Posted on Jan 03, 2009

  • 137 Answers

SOURCE: Having trouble keeping my 98 jeep grand cherokee running

i recommend cleaning the throttle plates. they are located unter the intake hose form the engine to the air filter housing. if you open them with the engine not runniong you will see they will be covered in carbon. use a good carb cleaner and a rag to wipe them clean

Posted on Jan 20, 2009

  • 6982 Answers

SOURCE: Valve knocks when running reaches 1500 rpm

First, nothing you have done has anything to do with valve tappet noise. What is your oil pressure? Have you positively identified the noise as a lifter (tappet), OR COULD IT BE AN ENGINE BERARING OR WRISTPIN? Other than tearing it down and replacing lifters, rockers or pushrods or possibly even the cam, if oil pressure is good, change the oil and put a quart of Marvel oil in there. If that does not clear it up in a few days, you will have to go inside the engine. You likely have over 160k on that engine...consider using a replacement. Get an older tech to listen to it...it takes years to be able to differentiate between different component noises with any accuracy.
Personally, without hearing it myself, I'm betting it's a rod knock.

Posted on Feb 20, 2009

r_mcalhoun
  • 166 Answers

SOURCE: 96 jeep cherokee idles high/accelerates by itself

try unhooking the cruse cable

Posted on Jul 20, 2009

  • 6982 Answers

SOURCE: 93 jeep grand cherokee. Starts and idles ok.

Being injected, the control system varies fuel quantity and does not directly regulate air flow. Therefore, having black soot on plugs tells you that there is too much fuel going into the engine. The O2 sensor tends to react to, more than control that. Missing can be the result of plug fouling. Backfire may be the result of a too rich fuel mix permitting unburned fuel to enter the hot exhaust where it re-ignites.
Where I would look first in your case is to the manifold air temp sending unit and the coolant temp sender as well. If either or both are out of range the computer may "think" it is running a cold engine and therefore adding additional fuel for cold start up,and not switching to normal run mode when the engine reaches operating temp. Once the plugs foul the engine will continue to run poorly regardless of other conditions. You can test each component individually using either chilton or haynes manual as a guide. You will need a decent digital multi-meter to do the tests.
You can also have a code test done at most major parts stores, but often if sensors are not bad enough to set a code but together are causing a problem, you may not see anything except the O2 sensor.
There are other possible causes such as worn out injectors, but most often that won't happen in all cylinders at the same time. Do testing first, correct whatever you find and then make sure plugs are clean. If after running, the O2 sensor continues to register a fault, then replace it.
Good luck...any further questions are welcome and don't forget to rate answers!!!

Posted on Feb 22, 2010

Testimonial: "Thanks. We will try it."

  • 645 Answers

SOURCE: my 1993 jeep grand cherokee laredo idles rough

usually rough Idle is not noticable at high ildle. Once it is idles normally try Disconnecting one injector at a time. If the idle stays the same than that cylinder is the culprit. Remove that spark. If it is wet than do a compression test. Should read better than 100lbs of compression.If compression is good take a spark plug and hook it into the end of the plug wire.Lay it across the intake,start the car and watch for spark. If you have spark than you probably have a bad injector. A miss will cause the vehicle to idle high. The computer is trying to keep the car from dieing out. Hope this helps. No spark do a tune up.

Posted on Dec 05, 2010

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

1996 Jeep cold start heater location


It likely has EFI (electronic fuel injection) and an idle air control valve that regulate idle speed. They can get gummed and fail to have a fast idle when cold, or get stuck the other way, and have a too fast idle all the or regularly take its time slowing down after you take your foot off the gas. An engine temp sensor can also cause a lingering high idle if it reports the engine as still being cold after warm up.

Aug 15, 2014 | 1996 Jeep Grand Cherokee

1 Answer

What is diagnostic code 22 for a 1994 Jeep Cherokee grand limited


That code is for the engine coolant temperature sensor. "...input above maximum acceptable voltage." I would try a new temp. sensor. If that doesn't fix it, you may need to have an engine scanner hooked up, and see what the sensor is sending to the computer, and go from there.
A bad coolant temp. sensor can cause hard starting like your symptoms.
.

Apr 25, 2014 | 1994 Jeep Grand Cherokee

1 Answer

High idle 2003 grand Cherokee 4.7 ho


spray carb cleaner to cold intake a see if the idle changes this is a way yo look for a vacuum leak

Aug 15, 2012 | 2003 Jeep Grand Cherokee

1 Answer

Engine stalls at idle at 35 mph at 60 mph speeds


I think you mean the engine stalls or cuts out at Idle/30/60 mph.
More info wanted,as first is it a Man/or Auto ,what engine have you got 6 or v8??? When last servised by who,How many miles on the clock,dose it smoke when driving or starting ,are the revs ok on idle ,,about what temp dose it run at the 30/60 mph etc etc???
PLEASE send all info, ..
Ron.

Nov 30, 2010 | 1997 Jeep Grand Cherokee

1 Answer

96 RS Camaro High Idle on Cold Start.


you prob need a coolant temp sensor

Oct 30, 2009 | 1996 Chevrolet Camaro

1 Answer

Cold idle stays on too long


Has it always behaved the same? It has sensors that detect engine temp, outside temp, humidity and altitude to give you the perfect fuel air mixture for the conditions. 1300 to 1500 rpm is not unusual for cold engine warm up. You could have a bad sensor, but the codes should have revealed that problem. 10 minute warm up is not outside the norm. at idle, but 7 miles driving should make it happen a little sooner. As for the the stick moving when you "get on it", that is normal engine "torque", your engine mounts give just a bit to allow movement and to keep that "torque" from being transferred to the body/framework of the vehicle. You have hard rubber mounts. As they "fatigue" you will notice this movement increasing slightly.

Jun 10, 2009 | 1989 Toyota Pickup SR5

1 Answer

No/low oil pressure, high engine temp


I think you have a bad ground on your engine gages...but, more importantly, have your oil pressure checked by a mechanic.  If it is indeed only 20 pounds the engine is sadly on it's last legs.
When you receive advice from this website you have to understand that without the item in front of us, we are only able to provide "a best guess" as to what the problem might be based on you description of the defect.  If you haven't described a clear and precise description of the defect you decrease the chances of an accurate reply.  Thank you.   

Apr 28, 2009 | 2002 Jeep Grand Cherokee

1 Answer

Car stalls


Here is the most common cause of surges and stalls and low idle, it is the idle speed control air-bypass valve and throttle valve (IAC for short), they get full of gunk over the miles and cause idle issues (stalls, low idle) like yours, Get a can of intake cleaner from any local parts store, not carb spray, intake cleaner, it is made by a company called CRC, remove the air intake hose to the engine, hold the idle high so the engine won't stall, then spray the can of cleaner into the intake while keeping the engine running, use at least 1/2 the can, shut down the engine and disconnect the battery for 5 minutes, then restart and complete a number of mixed driving cycles, town, freeway, stop and go etc., after a few days the problem will go away as the system will relearn to the clean intake.

Jan 14, 2009 | 1998 Jeep Grand Cherokee

Not finding what you are looking for?
2008 Jeep Cherokee Grand Logo

Related Topics:

54 people viewed this question

Ask a Question

Usually answered in minutes!

Top Jeep Experts

yadayada
yadayada

Level 3 Expert

60960 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

21949 Answers

Jeff Turcotte
Jeff Turcotte

Level 3 Expert

6812 Answers

Are you a Jeep Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...