20 Most Recent 2002 Jeep Grand Cherokee - Page 4 Questions & Answers

Mechanic seems rather odd considering it is the function of a mechanic to discover what is wrong. If owners knew what was wrong with their vehicles there wouldn't be much point in mechanics serving a four year apprenticeship learning the core skills and taking loads of exams. I was in training for seven years and I think I managed to scratch the surface but very little more than that. If it sounds like metal-to-metal contact, it probably is though the noise doesn't necessarily account for the poor ride. You have described symptoms that seem like a car with worn shock absorbers... It is worth noting not all shock absorbers are the same. I once fitted Gabriel brand shocks to a car and the resulting ride was so teeth-rattlingly hard it made the former ride seem luxurious by comparison. It is also worth noting that an unwise type mix can cause a most uncomfortable ride that one correspondent described as a sideways bounce. Such things would not account for the knocking noises. Modern vehicles tend not to be fitted with suspension bump stops but instead are fitted with similar hard foam components that act as auxilliary springs, often fitted on the piston rods of struts and semi-struts. These components are soon damaged if the car is driven with dud shocks, is heavily loaded or driven hard over rough ground. Speculation is pointless. In reality the pathway to a diagnosis is for an experienced person to go for a drive and then take a look underneath.

Seems to be having problems with the alternator. Alternator itself can be bad, but also the voltage regulator, which sits inside the PCM (powertrain control module). Don´t continue using with battery voltage around the 10V, because it will ruin your battery as well. Completely charge the battery with an external battery charger and let the alternator be checked out first.

was there a problem in first place to go to garage, have you looked at the oil yourself ? if there is no abnormal gear change or sounds i would think it would be fine. some gear oil is black in colour this can be normal. if anything the oil should only be checked for metal contamination. i.e its lost its viscosity and metal is rubbing on metal. i would think by now you would need the oil change if it has not been done but that is the only thing that should be done. if every thing is working fine just change oil.

Have you checked the front drive shaft U-Joints for excess wear and run out?

you need to have someone with a reader hook up to your jeep and clear the codes. even though you replaced the sensor your computer thinks it is still running on a faulty sensor

you meant its a NO CRANK engine.silent starter, say the word silent.even the starter relay must click.and if head lamps die, so will be the starter.due to a dead battery,sounds like a bad battery to me. dead or only DISCHARGED.if the Charge/battery lamp is off in the cluster driving. its ok. the alternator.starter car with the jumper cables connected and not next day.only live jumps matter. or you go know where.if you want to walmart they have tool there thattests the alternatorbattery and for phantom drains all in 6 min work, the tool does all the work.if the battery is charged, it will crank I betits discharging.for 1 of 3 reasons.1: its bad.2: the charge system is dead.3: phantom drains, it goes dead as you sleepthe head lamps dead is the big clue there.

forums cant fix tranmissions nor diagnose them. its like 1000 page book, why not buy a book on transmissions first. the see why it takes special testing. your trans shop is a crook. why not buy a scan tool (way cheaper than $3000 by 10 to 1) then scan it when it fails make sure engine does not overheat or trans. make sure no Px7xx codes. (trans codes) that is what you skipped, and the crook too, then you go broke.

post a questions or RTM here is the book posted 300 times here WJ jeep see them> read the engine pages..... its there, step by itty bitty step. http://jeepdied.com/books.html

IT DONT WORK THAT WHY. (on/off) NO ENGINE STATED, SO on exact answers. 4.0L or 4.7L ??? The engine cooling and HVAC rules govern this (computer tables and logic) the service manual cover that, did you SCAN the PCM at the failure then scan it again after, no? did you know some cars run the fans parked to prevent overheat soak damage to the engine and trans? all have hood sticker warning telling you to stay way from fans, , until fully cooled engine or pull battery neg lug for safety. just saying that so you are safe fiddling all cars. the fan(s) run via truth tables, logic (computer) if cold outside why run a fan?, and waste fuel and cause green house gasses for fun. or make noise for fun, answer it doesn't. it runs the fan ONLY when needed, is the answser and is very complex, the newer the jeep gets. On most cars even as old as 1995 , the condensor fan control would stay off if ambient temps are below 50f. this is not new logic. Chapter 24 covers HVAC. in The service manual SM. not only that, you failed to test the AC per the SM and failed to scan the PCM to see if there are HVAC faults. causing this fan disablement's. on purpose. this car come with 2 type HVAC, manual and ATZ (climate control fancy) the rules for each are not the same (potentially) the PCM controls the radiator fan on the 4.0L with a relay. so is 100% pure (ATZ/BCM/PCM) logic doing that. the 4.7L has hydraulic motor powered engine cooling fan as you many not know the A/C condensor rams hot AIR to the front of the engine RAD and cause it to overheat so the engine fan is very much part of this regulation system. The AC will also shut down for many AC related errors and will do so if the engine or transmission over heats. Self preservation. there are 3 , 4.0L systems, for fan control clutch fan or electric and one has a PWM modulated fan control module (its a transistor not relay in this case) her is what chapter 7 states PWM FAN CONTROL MODULE - 4.0L DESCRIPTION The pulse width modulated (PWM) radiator cooling fan relay is located behind the front bumper fascia below the right headlamp. OPERATION The PWM relay is used to control the speed of the electric radiator cooling fan. It allows for multiple fan speeds. This allows for improved fan noise and A/C performance, better engine cooling, and additional vehicle power. PWM relay operation is controlled by the Powertrain Control Module (PCM). To operate the PWM relay, the PCM looks at inputs from: † Engine coolant temperature † Ambient temperature from the body controller † Vehicle speed † Transmission oil temperature † A/C switch position (A/C request) the SM does not list all rule and tests for this device. more..? here more quotes from your missing book If an open or shorted condition has developed in the relay circuit controlling the electric radiator fan or fan control solenoid circuit controling the hydraulic fan, a Diagnostic Trouble Code (DTC) can be set. If the problem is sensed in a monitored circuit often enough to indicated an actual problem, a DTC is stored. The DTC will be stored in the PCM memory for eventual display to the service technician. fans stuck on quotes 1. Fan control sensors inoperative. 1. Check for DTC's. Verify sensor readings. 2. Fan control solenoid stuck 9on9. 2. Check fan operation speeds. Refer to fan speed operation table. 3. Fan control solenoid harness damaged. 3. Check for DTC 1499. Repair as required. 4. Transmission temperature too high. 4. Check for transmission over temp. DTC. 5. Engine coolant temperature too high. 5. (a) Check coolant level. Correct level as required. (b) Thermostat stuck. Replace thermostat. (c) Water pump failed. Replace water pump. (d) Coolant flow restricted. Clean radiator. (e) Air flow over radiator obstructed.Remove obstruction. the 4.7 liter engine the fan speed is base on above and says, A/C system pressures. the 4.7 then can can run at 500 rpm even when OFF. (SM) now how to test the fan. get engine hot, (drive 10miles say) then park, and lest engine idle until the engine overheats it will (but not in alaska, dig?) and then the fans come on at bout 225f .. (about this is ball park) electric fans if using a 4.7L say so, its totally DIFFERENT

without knowing the code numbers it is difficult to advise it could be a cam/crank position sensor failing, bad ground points Leave the ECM as it is running good and if that is failing there will be a heap of other problems check all harness connections for corrosion of pins even the plugs on the ECM check for cracked wires to the crank position sensor as it is reported that if that insulations is not in good condition then the sensors will give an intermittent problem

The transmission torque converter is not in lock-up, as the rpm is too highShould be about 2,800 tops at 65mph

make him do it again... ?

Try balancing & rotating the tires. If the sound is gone, problem solved. If it is rotated to a different spot theres the answer

typical jeep gremlins on a 17 year old car mechanics either replace all the computers and modules or throw lots of unnecessary parts into it with minimal results needs a volt meter an LED test lamp and a lot of time tracing the wiring faults starting at the battery through to the ECU and ignition

is this car in uSa, NO,or Europe?, you posted to a USA forum. ok? our USA Cherokee ended 2001. so my guess is you have a European Cherokee? KJ is like our KJ Liberty, using our name car is not the same,. (kinda SAME,but not identical) Forget that. ill answer simply, fuel tank has fuel pump to a filter above and fuel lines to the v6 fuel rails and last the Injectors, that is all there is on fuel side the injectors are fired by complex electronics called EFI try Chevron techron additive to tank (read bottle side do as says) end snake oil fixes....bla bla... rough idle is misfire, and 50 possible causes #1 cause is NO TUNEUP in last decade #2 did you scan it yet, to see who is misfiring, seems not. and more lots lots more, if not above one is bad fuel.. old or someone put wrong or bad fuel there. lots. P= fuel pump below F= fuel filer is here 2002.(again,USA MARKET) WHY ASK YANKS THIS? why not get the car serviced and now make it worse.? guessing.tune up, spark parts, filters. like that?do that?

the 2002 grand Cherokee WJ jeep, can be quada-drive ?or quadra-trac- II NV247 (transfer case)regardless of that... stay out of 4wd low, use low only on ice or dirt, dead slow.it will grind a bit going into low. low is never to be used on dry pavement.dry means, no ice.the book on car is clear, its for rock crawling off road only. (super low speed), put at least on tire on dirt then drive slow and shift out of 4wd LOW, lock,.if not, damage to the drive line can happendo not attempt this moving fast ever, (into or out of LOW)RTM, read it 2 times.

its grand cherokee, WJ jeepif it has quadradrive,its full timebut do no use 4wd low on pavement with no icegot this, see the words there?http://jeepdied.com/QD.JPGit can also have quadra-trac2, but it has same rules.missing 4wd low. requires no driver inputs.(means full time)first learn what is there (they are options,)this 4wd systemthen look it uphere and readhttps://en.wikipedia.org/wiki/Jeep_four-wheel-drive_systemspost a photo of your stick shifts, relatedand its obvious what your car had new, in 4wd.ok.check all fusesthen scan it.using any OBD2 scan tool, modern.that is first.if the scans tell you there are problemsthen work them or ask for helpor read the service manual on 4wd diagnosis.or get it serviced.