I ask this because about 5 yrs ago, my 95 se developed an issue where once I start the car. all gauges are fine.

but once car is up to running temp around 15-20 mins later the gauges act funny. my battery gauge will show 10 volts, mean while on my multi meter it reads 13.9, and my oil pressure gauge will go all the way down to red and set off the warning chime only when the car comes to a complete stop like at a red light, but once I step on the gas and take off again, oil pressure goes right back to 40-45 psi.

this has been happening for 5 yrs now. so im confused. confused cause when it first happened I did oil pressure test and it was fine, I removed my gauge cluster and cleaned all contacts and it still continued to do this.

someone said my engine can possibly have internal engine damage but it don't make any noises, it don't shake, it don't smoke, it has good power and pedal response so im stumped.

I even changed the oil pressure sender switch that's by the oil filter 4 yrs ago with a crappy duralast one and my issue still exsist.


can everybody please give me their thoughts on this weird issue ? maybe I should try to replace oil pressure sender again with a better name brand part ?

I have a feeling that the power or ground leading to the cluster has an issue. Does the oil gauge drop quickly/instantly or does it fall in a natural looking way along with revs?

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WHITE WHINE - 1992 SSE Supercharged 236.26 ci (.040 Over) 15.090 at 90.2 MPH on old engine w/ slipping trans & melted O2 sensor - Gen 3 M62 and matching TB, Gen 2 Pully, Zillamotorsports Ported LIM, YT 1.72 Roller Rockers, SII FPR & Injectors, Hypertech Thermomaster chip w/ 160 Thermo, TransGo Shift Kit, Infinity/Pioneer Speakers & a 10" Alpine Type R Sub, all the watts, 140 amp Alternator, Ricepipe CAI w/ heatshield, Pilot Angel Eye Foglights, Clear Corners, '02 17" Chrome Bent 5's, Magnaflow F-Body Muffler and Hi-flo Cat, Ceramic Coated Ported Exhaust Manifolds, Fan Override, Monroe Reflex struts, red calipers
2009 G8 GT - Sport Red Metallic, loaded, SOLO Axlebacks, Rotofab Intake, Tuned, autodim mirror, removed intake manifold cover, HSV GTS triple gauge pod, two tone red-hot shifter and HSV SuperSport steering wheel, GXP rear sway bar and diffuser, 3.45 diff and various Camaro suspension bits, LED Taillights

if im stepping on the gas the oil pressure stays constant around 40-45 psi. as soon as I left off the gas it drops all the way to red with same speed as rpms..

If you know the engine has good oil pressure, no worries on internal damage.

I have the pinout for the '93 and '98 if it helps. Expect to find that it needs to have the terminals resoldered to the PCB in the cluster and that there are some terminals on the wire harness side that need to be re-sprung (there is a small 'spring tab' inside the female terminal that is supposed to maintain contact between the two terminals), then cleaned with electrical contact cleaner and sealed with di-electric grease.

Also, check that all power terminals have battery voltage and that all grounds pass a continuity test to body sheet metal.

_________________
Boost addict


The Fleet:
'93 SSEi - Twincharged + manual Build thread
'97 Camaro - Top swap
'05 STS - V8, AWD, her DD
'92 Trofeo - Fair weather DD
'99 Montana - top swap 3800
'04 Sierra 2500HD - LLY Duramax

Current project:
Something cool, trust me.

Upcoming projects:
'92 Bonneville SSE
'87 LeSabre T-type
'67 LeSabre

Gone to greener pastures:
'84 Sierra Classic - Twin turbo 3800
'97 LeSabre - Top swap

RIP:
'86 LeSabre - pictures
'93 SE - L67

My bet is that the voltage to the cluster gets just low enough that some of the gauges drop too low, but it's not low enough to make the cluster freak out all together.

_________________

WHITE WHINE - 1992 SSE Supercharged 236.26 ci (.040 Over) 15.090 at 90.2 MPH on old engine w/ slipping trans & melted O2 sensor - Gen 3 M62 and matching TB, Gen 2 Pully, Zillamotorsports Ported LIM, YT 1.72 Roller Rockers, SII FPR & Injectors, Hypertech Thermomaster chip w/ 160 Thermo, TransGo Shift Kit, Infinity/Pioneer Speakers & a 10" Alpine Type R Sub, all the watts, 140 amp Alternator, Ricepipe CAI w/ heatshield, Pilot Angel Eye Foglights, Clear Corners, '02 17" Chrome Bent 5's, Magnaflow F-Body Muffler and Hi-flo Cat, Ceramic Coated Ported Exhaust Manifolds, Fan Override, Monroe Reflex struts, red calipers
2009 G8 GT - Sport Red Metallic, loaded, SOLO Axlebacks, Rotofab Intake, Tuned, autodim mirror, removed intake manifold cover, HSV GTS triple gauge pod, two tone red-hot shifter and HSV SuperSport steering wheel, GXP rear sway bar and diffuser, 3.45 diff and various Camaro suspension bits, LED Taillights

so should I remove the cluster and check all the connections ? and im pretty good with soldering, I have my own $150 soldering kit.. are there any pics floating around of what I should be looking for ?

I don't think I have any pictures of that from my fun with my cluster - I'll check.

You would be looking for a cold/cracked solder joint on the cluster connection. You usually need a magnifying glass to see them, and sometimes they just are not visible:

(example of a cracked joint)


Here is something I put together for another type of wire terminal. It's a cross-section view of the female terminal. The blue tab at the bottom would be the locking tab that holds the terminal in the connector, and the red tab is the one that keeps positive contact to the male terminal, that can sometimes get bent. It should touch the top of the female terminal as illustrated:

_________________
Boost addict


The Fleet:
'93 SSEi - Twincharged + manual Build thread
'97 Camaro - Top swap
'05 STS - V8, AWD, her DD
'92 Trofeo - Fair weather DD
'99 Montana - top swap 3800
'04 Sierra 2500HD - LLY Duramax

Current project:
Something cool, trust me.

Upcoming projects:
'92 Bonneville SSE
'87 LeSabre T-type
'67 LeSabre

Gone to greener pastures:
'84 Sierra Classic - Twin turbo 3800
'97 LeSabre - Top swap

RIP:
'86 LeSabre - pictures
'93 SE - L67

thanks matt, as soon as I get this replacement transmission put in Friday/Saturday I am going to jump right on removing the cluster fcuk and checking for broken/cracked solder joints on the pcb. you rock dude.. I just hope this is my issue.


and just out of curiosity, is it possible for a 3800 motor to have enternal engine damage to cause low oil pressure but still run strong and sound fine for 5 yrs ? lol

Honestly the 3800s have proven time over time to surprise us and run under unthinkable circumstances, but honestly, if it ran with LOW ENOUGH oil pressure, you'd likely be hearing from the motor by now. If the pressure was low enough, you would likely have heard noisy lifters, and could have spun some bearings. If the motor is quiet and acts happy, I'd say it's fine.

_________________



Joseph

Current: 2013 Infiniti G37 Journey
1999 Infiniti G20T - Sold
1999 Buick Lesabre - Race Couch - gone but not forgotten

I agree - I had almost zero psi on the gauge at hot idle after putting the L67 in the Bonneville - which explained the lifter ticking which turned into a racket you could hear a mile away, I put 20k+ miles on it that way - but I never spun a bearing or seized the crank (still needed machine work to fix though). I'm not kidding, my wife was in my car (That's why!!!!), picked me up after explicit instructions to keep it off idle: and not doing so. I heard it, was thinking 'that poor car', and then it pulled up to the door...

General rule of thumb - 15psi per 1000rpm on the mechanical gauge. If that checks out, then the problem is most likely in the cluster connections.

_________________
Boost addict


The Fleet:
'93 SSEi - Twincharged + manual Build thread
'97 Camaro - Top swap
'05 STS - V8, AWD, her DD
'92 Trofeo - Fair weather DD
'99 Montana - top swap 3800
'04 Sierra 2500HD - LLY Duramax

Current project:
Something cool, trust me.

Upcoming projects:
'92 Bonneville SSE
'87 LeSabre T-type
'67 LeSabre

Gone to greener pastures:
'84 Sierra Classic - Twin turbo 3800
'97 LeSabre - Top swap

RIP:
'86 LeSabre - pictures
'93 SE - L67

ok so I found oil in the connections of the oil pressure sending switch.. I cleaned off connections and blew then clean with a air compressor, then used electronic cleaning spray on them. but cant see if that was the problem as I have the old trans out the car and will be putting the replacement trans in this weekend when I get more time..

what are your thoughts on this ? why would oil being coming out of the connecter side of the oil pressure switch that screws in above the oil filter ?

Usually that's a sign that the sender is physically failing inside.

_________________

WHITE WHINE - 1992 SSE Supercharged 236.26 ci (.040 Over) 15.090 at 90.2 MPH on old engine w/ slipping trans & melted O2 sensor - Gen 3 M62 and matching TB, Gen 2 Pully, Zillamotorsports Ported LIM, YT 1.72 Roller Rockers, SII FPR & Injectors, Hypertech Thermomaster chip w/ 160 Thermo, TransGo Shift Kit, Infinity/Pioneer Speakers & a 10" Alpine Type R Sub, all the watts, 140 amp Alternator, Ricepipe CAI w/ heatshield, Pilot Angel Eye Foglights, Clear Corners, '02 17" Chrome Bent 5's, Magnaflow F-Body Muffler and Hi-flo Cat, Ceramic Coated Ported Exhaust Manifolds, Fan Override, Monroe Reflex struts, red calipers
2009 G8 GT - Sport Red Metallic, loaded, SOLO Axlebacks, Rotofab Intake, Tuned, autodim mirror, removed intake manifold cover, HSV GTS triple gauge pod, two tone red-hot shifter and HSV SuperSport steering wheel, GXP rear sway bar and diffuser, 3.45 diff and various Camaro suspension bits, LED Taillights

Had a Chrysler Fifth Avenue that had the same issue, only with the idiot light. it would be fine until it was at operating temp and it would flicker and then stay on at idle. was the oil sender. i replaced the light with an actual gauge after that happened TWICE.

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1992 Pontiac Bonneville SSE (3800 Series I, 277K miles and counting! with a horrific knock sadly)