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Oil Pressure Gauge Issues


NAXJA Forum User
Hey guys, once again i need help. the patient - '96 Xj Country 4.0, aw4, 242. 158,xxx miles on her. this is my girls daily driver, about two months ago her oil pressure gauge starting reading all whacky, it would just constantly bounce around from 10-80 down to 20, up to 70, just constant random numbers. i figured yeah ok the sender by the oil filter went bad, well i finally got around to replacing this over the weekend. i go fire up the truck, (motor was cold) and the gauge goes to 50 psi, i hit the gas, still 50psi, i drive it down the road and it does'nt move, 50 psi, warms up to full temp, still 50 psi, so basically no matter the temp of the motor or position of the trottle the gauge reads 50psi and does'nt move. then i heard fram filters can do whacky things to our 4.0's so i changed the oil and filter yesterday with castol gtx 10/30 and a pronto oil filter, but i still have the same problem. Do the actually guages themselves fail?? its just weird that i had the original issue and changing the sender seemed to have made it even a stranger issue. any help is appreciated. thanx.
make sure you didn't get a sending unit for a jeep w/ idiot lights instead of gauges, I would think one for a light would work like an on off switch instead of off resistance explaining one pressure reading like your describing
I've replaced these several times on several different vehicles. They're certainly easy to mess up when changing filters if you accidentally put any pressure on 'em. They're more expensive but I've had the best success using OEM from the dealer. I've had more than one chain-store senders do exactly what you have described right from the get-go.
If you have to pull it out again, I would suggest hooking up a mechanical gauge temporarily so that you know the real story
Sounds like you got the wrong sending unit... Installing an "idiot light" sender seems like it would have that effect. As was said above, its an on off switch. I would see if you can return that one to the parts store...just tell them they looked your part up wrong, which they probably did.

When I worked at autozone, there were plenty of times that I looked up senders and it asked if it was gauges or lights. SO some lazy counter jockey probably just hit whatever came up...or didnt read the description under the part number.

Do you still have your old one? If you do there is probably a Chry. part number on it. That might help ya too. Most parts houses can cross reference OEM numbers... Good luck!

Sounds like the wrong sender to me the price of an idiot light is pretty cheap ($5) the gauge is about 15 to 20 the physical size is bigger than the idiot light sender as well.