Buy Now | Log In | ALLDATA Corporate Site | AutoZone.com
Back To Home Page
Log In To Your Subscription
Go To ALLDATA Back Home
Buy A Subscription! Back Home About ALLDATA Information View Sample Vehicles Read Testimonials View Factory Service Bulletins and Recall Titles Contact Us
Dowload Our Navigation Chart
February 2015: New vehicles added including 2014 GM.
• View New Vehicles
October 2014: Release of 2013 along with initial 2014 Vehicles
• View Vehicles
View All News and Updates:
• Go To News
Tech Tips
  Read All Tech Tips

ALLDATA Tech Articles Are Updated Weekly
• View All Tech Articles

  Dodge Durango: Brake Pulsation Problems In Paul's Durango
• Read Dodge Article
 
Fixing A Smelly Audi Audi Tech Tip: A4 begins to Smell caused by a Faulty Hose Composition
• Read Audi Article
Why Do You Need To Change Your Timing Belt? Why Replace Your Timing Belt
• Read Belt Article
Jim Grant Tech Tips Jim Grant Tech Tips
A collection of helpful articles based on reader submissions
Home >> Featured Tech Articles >> Go Back
   
  Jim Grant's Tech TipsJim Grant's Tech Tips
Below is a collection of Jim Grant's Tech Tips sorted by Vehicle Make. These Tech Tips were answers to questions submitted to Jim by ALLDATAdiy.com users over the course of many years.
If you have any questions, please feel free to email us.
 
 

Miscellaneous
Acura
Audi
Buick
Cadillac
Chevy
Chrysler

Dodge/Plymouth
Ford
GMC
Geo
Hyundai
Honda
Isuzu

Jeep
Lexus
Lincoln - Mercury
Mazda
Mercedes
Mitsubishi
Nissan
Oldsmobile
Pontiac
Saturn
Subaru
Toyota
Volkswagen
 
   
  Jim Grant's Tech Tips

’00 Jeep Grand Cherokee, Oil Pressure up and down

Q: I was driving down the interstate in my ’00 6 cylinder Jeep Grand Cherokee and I stopped at a station. When I started the engine there was no oil pressure. After checking the oil & everything else it came back. Now about once a week the “check gauges” light comes on “no oil pressure” after it runs a little while it comes back. I changed the oil pump and the sending unit, oil and filter but it has not helped. The idle pressure is not as good as it once was but it’s okay. Seems to be a ghost. Is there such a thing as an oil switch on this model? I only know about sending units..

ED

A: The first thing you should know is that the oil pressure gauge along with just about every part of your instrument display is computer generated. That’s right it is not real. It is only the result of a computers interpretation of data that is then displayed on the instrument panel. The only hard wired (stuff that is connected to what is it’s displaying) is the 4 wheel drive indicator, left and right turn signal indicators and the brake warning light. Maybe they didn’t trust the computer with that type of information, who really knows? An oil pump is a mechanical device and when worn, loose or with a restricted pick-up screen can be erratic. If the engine has worn bearings then oil pressure will be low all of the time and not just once a week. You’ve done all of the right things with replacing the oil pump, etc. I hope the oil pan was cleaned and the pick-up tube & screen were replaced with the new oil pump. But now there’s a question of was the oil pump really the problem? Well the oil pressure gauge said there was a problem. But was it? Replacing an engine in today’s vehicles is big money and having that engine fail some place other than in a garage driveway causes more money and aggravation. Here’s what I would do. I would install a mechanical type oil pressure gauge. The type that has a line that takes oil right from the engine to the gauge for the pressure reading. You could do it 2 ways, just monkey it in as a temporary device or install it neatly for the long haul. Then just drive the vehicle and compare the dash display oil pressure to the gauge pressure. If there is a disagreement I would trust the mechanical gauge over the computer’s interpretation. If the oil pressure really does drop on both gauges, then you’d better be looking more closely at the engine’s lubrication system. If it goes the other way? Don’t you just love computers!

 
     
Have any Questions About ALLDATAdiy.com? Please Email Us
Buy Now | Log In | About | Sample Vehicles | Testimonials | Join Affiliate Program