From MyHonestMechanic.com

Front End Problems
1994 Jeep Grand Cherokee Noise On Turns
By Austin Davis
Sep 3, 2008, 11:17

Reader Question
Hi Austin,

Just wanted to know your opinion on a problem I'm having. I currently own a '94 Jeep Grand Cherokee Laredo and its been a worthy on and off-road vehicle.

Lately I've been noticing the Jeep "lugging" when I turn the wheel 3/4 to a full turn. Its usually more evident when I'm coming into my driveway or pulling into a parking stall. When backing out of a space, I don't notice the lugging. Could this be a problem with my front axle?

Hope to here from you soon,
Jon




Hi there Jon,



I think what I would first do would be to clean your throttle body. This should be part of your routine maintenance anyway, and a dirty throttle body causes all kinds of low speed/idle complaints.

It’s pretty simple and fast to do and any fast lube place should be able to do it for you while you wait. We charge $80 in my shop. If nothing else, you should notice a much smoother idle and faster starts.



Here is more info on the throttle body

Throttle Body Cleaning



Blessings,

Austin Davis


Hello again Austin,

I recently just changed my oil and cleaned my throttle body as you suggested. The Jeep does start faster and idles much smoother but it hasn't improved the problem.

I have noticed that the lugging and jerking on a 3/4 to full turn does get better during cooler weather though. Someone suggested that my tie rods are shot, someone else said to just replace the front axle and swap one for one from a jeep in a salvage yard. What's your opinion on what I should do?

Also on another note... my friend has an older Jeep like mine (not so sure if its a '94 or what), but his jeep has some drive train noise he can't get rid of. =\ How do you suggest he fix this problem?


Many Thanks,

Jon



Hello again Jon,

I am still under the assumption that this is an engine driveability issue not a suspension or steering linkage issue....do you concur? I also do not think this is a safety issue or an issue that SHOULD require spending lots of time and money trying to solve, or at least from what you have told me in email.

To me, this still sounds like a low idle or a rough idle issue with the engine. When you turn the wheel hard to one side at slow or low speeds you are lugging or straining the engine slightly.

If the engine idle is too low, the computer will try to increase the idle speed during this load time to prevent the engine from stalling. I am assuming you feel this sudden increase in idle speed and that is producing the jerking sensation.

Some vehicles have a Power Steering low pressure switch that is located in the high pressure Power Steering hose. This switch increases the engine idle speed when the power steering load is too high...usually during low speed turns or when parking. I am not sure if your vehicle is equipped with one of these or not, but would be worth a look.

So, cleaning the throttle body and increasing the base idle would be the first place to start. Do you have a Tachometer? Is the engine idle speed to low with your foot on the brake, A/C on and engine running in Drive?

I would expect it to idle at about 800+ RPM in this situation. If you are less than 800, maybe you can get a fast lube place to try and manually increase the base idle speed for you slightly and see if that helps. Other than that, I can only suggest you have a mechanic drive this vehicle with you and see if they have any ideas.

On your friends vehicle....these older Jeeps are just noisy, especially in the drive line and tire tread. I would make sure the rear end and transmission has plenty of fluid in them and I would inspect the u-joints and tires for wear. I would say that 90% of the time with drive line complaints a unevenly worn tire is the culprit.

Try moving the rear tires to the front and see if the noise changes, and if it does he might need new tires to quiet the noise. SUV type vehicles really need to have the tires rotated and balanced every 10K miles or so to prevent uneven noisy tire wear.

Blessings,
Austin Davis

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