20 Most Recent 2001 Jeep Grand Cherokee - Page 2 Questions & Answers

Your catalytic converter is not doing it's job efficiently enough and it is setting off your sensor. This problem is emissions problem and usually has no effect on the operation of your vehicle( unless the converter clogs) As long as you don't live somewhere they do emissions test you don't really have to worry about it. However if you want to fix it you can take converter off and run a straight pipe or to do it "right" you could go pay way to much to get a new converter put on.

The OBDll system will need to be reset with a scanner. Waiting for the computer to do a system can take time and mileage.

Three possible solutions:

1. Bad Thermostat

2. Fan Relay (most likely)

3. Bad Fan

When the GC reaches a temp of 180 Deg. F the fan relay sends a signal to the fan to turn on, once the temp lowers (around 155 Deg. F) the relay turns off the fan, and so the cycle continues. If the relay is bad there will be no signal to the fan to run. While you are driving your vehicle there is ambient air moving thru the radiator, cooling the engine, but once you encounter slow/heavy traffic or stop there is no air moving and the temp goes up, the fan will not kick in and the vehicle will overheat.

If the fan motor is not working the same will happen, but a more expensive fix, as the motor comes with the fan.

If the Thermostat is stuck in the open position, the water travels to fast in the engine and heat exchanging is not an efficient process, therefore the vehicle might overheat when stopped or in slow traffic.

With all the problems, you might have a module problem. Make sure it is alright.

Or they gave you the wrong line. There may have been a design change though. Ask the dealer

Sounds like the relay that runs the fuel pump. The computer may be reading no oil pressure and shuts the engine down Check the oil pressure when it starts with a manual gauge. You may need to prime the oil pump.

I got this free Pdf manual from reliable-store for free and I don't think Ive visited a mechanic or fixya for help for more than 3-4 times out of the 20 times I fixed the chipper in these 4 years

it is on the valve body. usually in a solenoid pack

The electronic fan relay on this model fails very often, causing the problem you describe. I attached a picture of the location.

I suggest you get one of those manuals people get nowadays to do it yourself.. My nephew use it to repair my car and it's totally repaired now. Here's the website he bought it from. reliable-store.com

Steve is right on the money. You engine is staying cold too long. I assume you probably don't have hot heat like you use too either.

try air mass meter

If there was a trouble code, the code should tell you which one? bank 1 or bank 2, and or sensor 1 or sensor 2. Bank 1 on a v engine is the bank with number one cylinder. Bank 2 is the other bank. Some sensors are labeled upstream and downstream in relation to the cat, before or after. Upstream is senor 1 and downstream from the cat is sensor 2. Is it clear as mud?

I would check to see if the vehicle had an accident and the inner panel or insulation was not installed or not installed properly. Check the under side of the vehicle on the passenger side and make sure the rocker area is not damaged if the vehicle went off road and hit or landed on s large rock. If you have a vent not the inner kick panel, the vent may not be closing if it is electronic or the vent is not closed completely.

The car Gods created check engine lights so people don't have to guess at where to start. Get the codes read. Then you'll have a starting point. Waste of time to guess until you do that. Check engine light on Part Ricks Free Auto Repair Advice

If you have a high mileage vehicle, or you have purchased this Jeep second hand, it could be a clogged cooler that is causing the overheating issue. How did the fluid look when it was drained? Pull the lines off at the transmission and at the cooler. Use compressed air with a rubber tip to blow out the cooler lines. If the lines are not clogged up, then focus on the cooler itself. If it is the original cooler the factory installed, it may need to be replaced just based on age. Hot and cold temps will cause ANY material to fatigue. Is the cooler clean (no debris between the fins or behind the cooler)? If you live in a dusty environment, this could cause enough heat build up. To increase the cooling efficiency, you can move up a size on the cooler and you can use some spacers to increase the gap between the back of the cooler and what ever it is mounted next to. More air behind it will help it cool a little better. Since it is a Jeep, if you have off road lights or a winch mounted in front of the cooler, you may want to consider mounting it someplace else to maximize the air flow it receives. Other than cooler woes, I don't have many more guesses. If it were electronic you may or may not be getting a Check Engine Light. Might want to call a local dealership or a transmission shop to see if they have seen anything like this before.