birdman

iTrader: (1)

My 2000 GC (4.7L). I just had my oil changed a week or so ago. Before I got it changed oil pressue was fine. Now it maxes out but then it drops to normal pressue then bounces back up? has anyone seen this before. Oil level is fine. I just find it very strange. Everytime I see it high all I can think about is BOOM while on the highway!!
If I am crusin' at around 100 km/ph it rides high then if I step on it to make a pass roll for a bit around 120km/ph it drop down.

04WJGuy

Oil guages in these thing's are hard to trouble shoot. Mine sitts on zero for about 10 seconds then goes up to it's normal position and never moves until I shut it off. Other people say there's never stop moving.
You can always tap into the oil sensor location and install a mechanical guage if you want and run it inside or just pop the hood occasionaly to see what the pressure is.

CrazyWJ242

mine is the same as yours dan, 10 secs then constant pressure, just a bit above the middle, what that references to in pressure i dont know... but i believe this to be normal lol

going all over the place is reminding me when i had that floating valve in my Dakota's 5.9L when the float would happen, the pressure would spike up since the compression loss in that cylinder would go around the valve staying open and up into the crankcase...and changing the pressure until it was ventilated...

Trailhawk

i got a 96 GC (5.2) ran fine till i paid someone 2 change my oil (usually do it myself) got about 10 km and i lost all oil pressure... at first i thought maybe it was just a sensor, brought it back they changed it again they said it was dry underneath it wasn't leaking and now it knocks and pings... any ideas???

mattz

Hey birdman maybe its a bad filter. Very unlikly but possible. It was the only thing that changed. Might be worth just switching out the filter to be sure. What kind of filter did they put in? Usualy they use cheapos.

birdman

iTrader: (1)

I thought the filter too! oil has been changed again and still pressure is up and down and all over the guage! WTF I say! GC still runs okay though!

I just find it strange

mattz

I think you should try hooking up a guage and see if the pressure is fluctuating in the engine. And then you can determine if it is the gauge or the motor that has a problem. Also maybe check the sending unit and the wires.

WJCraig

I've had that a few times...well actually, the opposite of that. Dropped to zero then returned to normal with Fram filters...Or maybe it was just a coincidence that it happened soon after changing filters??? But it did happen twice...

rfdude

I just went through the pain of a bad sensor (99 GC with 4.7l)..mine was fine then one day I was driving to work and stopped at a stop light to hear the check engine light come on....looked down to find 0 oil pressure! Revved it back up and back to good. Stopped checked oil, all ok. Started back up and all fine again. This went on intermittently for 1 week and I finally couldn't take it anymore and bought a sensor (after reading many posts on the web). First sensor was an aftermarket one and worked for about 5 minutes then started leaking. I then read a post that mentioned to only use OEM sensors...returned defective one and bought OEM ($72), installed it and has work 100% ever since.

I read one post from a Mopar tech that 90% of all sensors fail (can easily tell by checking if they are leaking oil is the obvious way). They fail in various forms, from mine to what sounds like yours is doing. I would recommend changing out the sensor as a cheap fix first (be sure to check oil pressure first with a mechanical gauge before putting the new one in).

Good luck, hope this helps!