Low Oil Pressure

Oil Pressure Very Low on Jeep Grand Cherokee

Q:My Vehicle is 1996 Jeep Grand Cherokee with a 5.2 liter engine and the oil pump failed on vacation. The mechanic replaced the main, rod bearings, seal and oil pump. Now when the engine is started cold the oil pressure is fine. After warming up the idling oil pressure is 20 PSI and drops to just above zero when placed into gear. When the Jeep is moving down the road, the oil pressure is 20-30 PSI.


A: I’m concerned a bit with your oil pressure readings. The first thing you should do is have a mechanical oil pressure gauge installed and check the readings to confirm that the dash display is accurate  If the mechanical reading is the same as the dash gauge readings then you have problems, and here is where I have a problem. Why were the rod and main bearings replaced? The likely answer is because they were damaged. If they were damaged what did the surface that they rode against look like? I’ll tell you right now, damaged! If an engine loses an oil pump and the main and rod bearings are damaged I can assure you that the surface (crankshaft) that they ride on was damaged as well. So now ask yourself what happens if you place new parts against damaged old parts? I’ll save you the time, you get low oil pressure. When the oil pump failed the rod and main bearings rode against the crankshaft main and rod journals with no lubrication. The bearings are the soft part, but the surface on the crankshaft went down with the bearings. If I’m wrong then you have bad camshaft bearings. In either case, the engine has to come out of the vehicle to repair it correctly. Or should I say pull the check book out to repair it correctly.

Cruise Control Not Working On Jeep

Jeep Cherokee Cruise Control Has No Power

Cruise Control Fuse Location

Q: Its a 1996 Jeep Grand Cherokee and I cannot find a fuse for the cruise control, and it seems to have no power to it. The light on the dash will not come up when the cruise control is activated. I have looked under the hood and on the passenger side door panel fuse holders, and the cruise control doesn't seem to be indicated in those two areas.


A: You’re not really going to find a fuse for the cruise control on your Jeep. Why? The cruise control unit is controlled by the vehicle computer and receives its power supply from the same computer. If power is not being supplied to the speed control servo you want to inspect the stop light switch. The stop light switch, on your vehicle is really 3 switches in one. One part of the switch is for the stoplights. The other two parts are for the cruise control and, if not operating correctly, the cruise control will not operate. Also be sure to check the vacuum supply to the cruise control unit. It is not uncommon for a vehicle of that age to have cracked vacuum hoses. A cracked vacuum hose will result in a loss of vacuum supply. Too little, or no vacuum supply equals no cruise control. There are a few checks you can make with a voltmeter, but to get down and dirty with the cruise control on your vehicle requires a computer scan tool too.

Check Engine Light Comes ON again n again

Jeep Cherokee Check Engine Light Will Not Reset

Q: Problem noticed on 1996 Grand Cherokee Lorado has 97K on it. I have taken care of the vehicle pretty well. Recently driving in upstate NY the check engine light came on. When I shut the it off and started it after a few minutes, the light remained on. I went on to remove the battery cable in order to reset the computer; this worked for a little while maybe 3 weeks. Within that time, I was getting very bad gas mileage, so I changed the O2 sensor. The one near the exhaust manifold was fouled and checking the one on the converter was ok . Also I’ve poured Textron additive because it was sluggish on initial take off from a stop. At times I’d lose power when I accelerated hard in overdrive. The light went on again, even when I reset it again by removing the battery cable it came on within the hour and the mileage is still bad. What do you think could be the cause of this problem, or do I need to go to the dealer for a diagnostic check up.


A: Yes you need to go to a dealer or and independent repair facility to get the answer to your vehicle’s problem. Also, whatever you do, "do not" unhook the battery before you go! Unhooking the battery causes the computer not only to reset, but in the process all information that the computer has to share, with the technician servicing your vehicle, is lost. An empty computer file will have no diagnostic information and you will get a bill for telling you there is nothing wrong. So, make the appointment, drive the vehicle and leave the battery alone. With the Check Engine Light on the computer will have the information you need to get your Jeep back to good running order.

Vehicle Goes Opposite direction at Sharp Turns

Turning Issues and Thumping Problem


Q: While engage the 4WD on 1996 Jeep Grand Cherokee, and turn to sharp corner, the front wheels sort of take me in the opposite direction and a thumping takes place...it is also really hard to steer. This only happens when I take a sharp turn doing 5 mph or when I turn at a green light, turning sharp while accelerating in the turn. Others have told me that they have the same problem with their Jeep. Is it true that Chrysler Corp had a recall for this problem in 1996?


A: Did you know that many 4x4 or All Wheel Drive (AWD) vehicles are not really 4x4/AWD? Many of these vehicles are either a front or rear wheel drive. It’s the technology designed into the drivetrain of these vehicles that allows them to transform, in merely a second, into a 4x4 or AWD vehicle, and you’ll never feel it happen, unless there is a problem with a device called a Viscous Coupler. A Viscous Coupler compares front wheel speed to rear wheel speed. If a difference is noted (rear or front wheels spinning) the Viscous Coupler engages and directs power to the wheels that are not spinning as well, making them all work together. If your vehicle is feeling jerky, and acting as if something is binding while turning sharp at low speeds, then the Viscous Coupler should be inspected. Diagnosis of the coupler takes a whole 5 minutes, but the repair will put a sizable dent in your checking account.

Vehicle Shudders while going Uphill

Jeep Grand Cherokee, shuddering

Q: Its the 1996 Jeep Grand Cherokee with 72K. All routine maintenance performed regularly without any missed. The vehicle is in great working order except for the following problem. Our check engine light keeps coming on when accelerating up hills at 55+mph. When we are about at the crest of a hill the light starts flashing then when the vehicle starts to down shift it starts shuddering real bad. This shuddering will last until you back off the gas and slow down. We have had the valve springs replaced, then had the mechanics do some work (because of the codes thrown) and this last week a new computer was installed. Two days after the computer was replaced the check engine light came back on under these same conditions. What could be the problem?

A: ALL DATA IS GREAT SOURCE. Join ALLDATA.The ALLDATA Information System shows several Technical Service Bulletins (TSB’s) that are related to driveability problems with check engine lights coming Here is the procedure explained for you to understand.
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The computer will report information to the technician that is not valid and send him/her down the wrong diagnostic path. With the recent replacement of the vehicle’s computer I would hope you got the latest and greatest software update. No, your Jeep isn’t running on Windows 98. If the computer is up to speed then the concerns move to the ignition and fuel system. If the problem is happening as the transmission down shifts and the engine RPM jumps higher than the norm, there may be a problem with the ignition wires. Strange as it may seem, we’ve found that under load and high engine RPM tired spark plug wires will introduce an immensely confusing engine skip that will not only turn the check engine light on, it also sends the computer into the high alert mode causing the check engine light to blink. The blinking check engine light on most ‘96 and up vehicles is the computer attempting to alert the driver to the pending doom of the catalytic converter. In closing, do not ignore the fuel system as a possible cause. A fuel pressure gauge should be installed and the vehicle driven in a manner that causes the engine to go into convulsions. Only then could you be sure of the abilities of the fuel pump. The fix will likely be simple. It’s finding the cause that will drive you nutz.

All Gauges Not Working

Troubleshooting Gauges Issues On Jeep

Jeep Cherokee, Gauge Problems 

Q: All gauges: The speedometer, tachometer, and gas gauge on 1996 Jeep Cherokee not working.Tried replacing the instrument cluster pod and still have the same problem. When they went out they would work off and on and the needles bounced around at times, then went out for good. Any suggestions?


A: Start with checking the fuses. The number 7 fuse in the fuse panel is a main player in powering up the instrument cluster in your Jeep. You should also realize that the action of the instrument cluster displays (speedometer, tachometer, gas gauge, etc.) are primarily a result of information processed by a computer called a Body Control Module (BCM). Because so many of your gauges are acting strangely the BCM is suspect. The BCM does have built in diagnostic abilities that can be accessed with a scan-tool. Virtually all of the lights and gauges on your dash can be operated via the scan-tool, through the BCM, for confirming function. Before replacing any more costly instrument clusters or installing a replacement BCM (the cost of a replacement BCM will create respiratory problems), be sure to check the fuses and electrical connectors. Proper diagnosis will save you money.

A/C blows on High Mode Only

Hi Speed A/C Blower Only For Jeep Cherokee

Q: Suddenly, Air condition will only work on the HI setting on my 1995 Jeep Grand Cherokee. If  set  to any other setting, no air will blow out. This sounds like an electrical problem but I’m not sure. Any ideas?

A: A very common problem.Your Jeep may be in need of a blower resistor. When you turn the blower speed control you’re directing electricity though different paths, all of which go to the blower motor. When you select low speed through mid speed you are really directing the electricity through a part called a resistor block. The resistor block has different resistors that control the amount of electricity that goes to the blower motor. But why only high speed? When the blower speed selected is high the resistor block is by-passed and full electrical power is directed straight to the blower motor. In most cases all that is needed is a new blower resistor block to return blower speed control.