Oil pressure needle bouncing around

**austinWS6** · 03-23-2009, 11:57 AM

My oil pressure gauge is bouncing around in a way that it had never done before. It is moving back and forth very quickly, but not the entire range of the gauge. Kinda like a 1/4 inch back and forth. This is on a 2002 WS6 Trans Am. Any ideas what might be causing this? All the other gauges are working normally.

**FORD RECOVERY EXPERT** · 03-23-2009, 12:08 PM

either sender / gauge servo Problem, or loose connection....

**Justin93** · 03-23-2009, 12:26 PM

Have you recently done any work to the motor? or is it still stock? I had this happen after a head and cam swap and it turned out to be a incorrectly seated oil pump O-ring.

**ebdboudreaux** · 03-23-2009, 12:35 PM

what #'s is it staying between?

**austinWS6** · 03-23-2009, 12:40 PM

Engine is still stock, and no, I have not done anything recently. I did just get the car repainted and put in a new radio. But, it was working fine after that. I just noticed this yesterday.

As for the range, I'd have to look again to see what range. I think it was in the normal range, it just acts like it has the shakes. :P

**shady milkman** · 03-23-2009, 12:51 PM

mine started do that a little more then usually..but i broke the shit out of my opsu and replaced it and am working out alot of weird things after my ls6 intake manifold

**austinWS6** · 03-23-2009, 01:11 PM

Did replacing the oil pressure sending unit fix your oil pressure shake issue?

**shady milkman** · 03-23-2009, 06:40 PM

Originally Posted by austinWS6

Did replacing the oil pressure sending unit fix your oil pressure shake issue?

not really...i just fixed it not long ago..it still moves..but doesnt bounce...my opsu broke durring the ls6 install ..so my needle wasnt moving at all

stayed at 0 ...but after i replaced it it jumped a little but now it is much more stable..oddly enough

**Justin93** · 03-27-2009, 05:24 AM

Originally Posted by shady milkman

not really...i just fixed it not long ago..it still moves..but doesnt bounce...my opsu broke durring the ls6 install ..so my needle wasnt moving at all

stayed at 0 ...but after i replaced it it jumped a little but now it is much more stable..oddly enough

Did the wire to the sending unit have any damage? I just did a fast swap for one of my buddies in a local Fbod club that Im in and when he pulled the intake out he snagged the wire and tore off some of the insulation, which caused his bouncing issues. A little electrical tape solved his problem.

**shady milkman** · 03-27-2009, 05:30 AM

no it looked good..i didnt torque down the opsu enough so i was getting a oil leak...my needle is much more stable now that i torqued it down...and now it chills out at closed loop at 40-43psi and durring cold 60psi..i couldnt tell you what it would be at if i went wot before closed loop...i dont do that

**TransAm11973** · 03-29-2009, 07:51 AM

austin,....is it bouncing when you are sitting at a light or is it bouncing while you are accelerating?

**TransAm11973** · 03-29-2009, 07:53 AM

mine moves a little bit when i am sitting at a light, but only maybe 4-7 psi..then once i get on the gas it all even from there. I would say that if its a massive fluctuation while at a light or during accel then you sending unit is bad....or may be the actual pump

**austinWS6** · 04-09-2009, 07:36 AM

It's bouncing almost all the time. I bought a new oil pressure sending unit and I'm going to try that this weekend...

**Circa307** · 04-11-2009, 10:09 PM

mine does that WAVING thing bad. what is it??? did you ever figure it out??

**austinWS6** · 04-17-2009, 10:20 AM

I think replacing the oil pressure sending unit will fix it. But, I've been too busy to replace mine yet. It's on the backside of the intake manifold near the fire wall. I have the part, just no time so far...

**halosix90** · 05-19-2009, 08:58 AM

Did anyone confirm that this issue is a bad pressure sending unit? My car does this almost all the time. Doesn't matter if it's in park or in gear but it seems to be more drastic when it's in gear. Gauge bounces all over the place. Doesn't seem to be burning or leaking oil. Could it just be the gauge that's bad? If it's the sending unit, how difficult is that to replace?

**shady milkman** · 05-19-2009, 12:35 PM

Originally Posted by halosix90

Did anyone confirm that this issue is a bad pressure sending unit? My car does this almost all the time. Doesn't matter if it's in park or in gear but it seems to be more drastic when it's in gear. Gauge bounces all over the place. Doesn't seem to be burning or leaking oil. Could it just be the gauge that's bad? If it's the sending unit, how difficult is that to replace?

well mine has settled down since i last posted...i would think its the opsu ..its easier and cheaper to fix then a gauge. the opsu is behind the intake manifold
..if you get a opsu socket that fits it..you dont need to remove the intake to change it...so its a relatively easily fix

**Y2KPewterSS** · 05-19-2009, 07:47 PM

Mine bounces around too. I changed the OPSU and that helped some, but it still bounces around at a light or during idle. Its not a drastic bounce, probably 5 PSI if that. I bought a new oil pump that I will probably swap out soon, but I don't know for sure what the cause is.

**shady milkman** · 05-20-2009, 09:05 AM

Originally Posted by Y2KPewterSS

Mine bounces around too. I changed the OPSU and that helped some, but it still bounces around at a light or during idle. Its not a drastic bounce, probably 5 PSI if that. I bought a new oil pump that I will probably swap out soon, but I don't know for sure what the cause is.

yea its normal i am pretty sure..since oil pressure is resistance and is never at a constant level unless the car is off