Low Oil Pressure.. - ZR-1 Net Registry Forums

maxxpower · 05-13-2011

Hi All...

It's been a while since I've been on the forums as unfortunately my '91 ZR has set idle for the better part of 2 years as life and building a new house got in the way. However it did get a little run time shuttling it from here to there. All I can say is, with as crazy as things have been the last couple of years, thank goodness the car always started, ran perfectly and never gave me a moments concern! Thank you Marc!!

Anyways, I had the car out yesterday getting my emission test done (had to put cats on it first) and when coming back I was flogging it a little bit (as I always do) and the LT5 didn't miss a beat, pulled strong, felt and sounded great! But, a few miles down the road I noticed the oil pressure about a 1/3 of what it normally is and when I slowed to an idle the pressure gauge went hard to 0! The gauge wasn't erratic at a steady rpm, but wasn't completely solid as it has been in the past. There was also no strange noises or warning lights, so I basically didn't let it go to an idle again and limped home where it sits now on the hoist. I had a good look and didn't see anything obvious so I pulled the oil drain plug figuring an oil change couldn't hurt anything and left it. I have run Amsoil in it since new and the oil always looks good coming out. This time was no exception, all looks normal. The car has 36K kilometers (23K miles) on it, most of them a 1/4 mile at a time.

I don't know if the few runs to 7K had anything to do with it or if this was just a coincidence? I was just wondering if there is a common item that others have had the same condition with or any thoughts as to what might be wrong... oil pressure sensor, switch, oil pump bypass stuck??

Thanks... Greg

gbrtng · 05-13-2011

Change the oil pressure sensor - it's behind the filter - common failure.

maxxpower · 05-13-2011

That's what I'm hoping for, I've already picked up a new sensor and will try it on the weekend if it ever stops raining here. : )

Thanks for the reply!

GOLDCYLON · 05-13-2011

Quote:

Originally Posted by gbrtng

Change the oil pressure sensor - it's behind the filter - common failure.

X2 and you will need a special deep socket to get it off.

GOLDCYLON · 05-13-2011

And welcome to the forum

maxxpower · 05-13-2011

Thanks to you also Goldcylon! In fact on my travels to the dealership to pick up the sensor, I met up with my Snap On dealer and got one of those deep sockets along with a new oil pressure test kit.

Although I am new again here, I was once a more active member as I have been a member of the ZR1net registry since the beginning (member 126) and the ZR-1 net before that, and the ZR1 Owners before that, etc.

Anyways, looking forward to the summer and new found time to enjoy it!

ittlfly · 05-13-2011

Quote:

Originally Posted by GOLDCYLON

X2 and you will need a special deep socket to get it off.

We both learned that lesson....

xlr8nflorida · 05-14-2011

Agreed, that is a 10 Minute job and $20 fix.

I had the same problem about 10 years ago.

Kevin · 05-14-2011

Quote:

Originally Posted by gbrtng

Change the oil pressure sensor - it's behind the filter - common failure.

even more common when you send your car to a dealership with an LT5 certified tech and they manage to bust yours...

maxxpower · 05-16-2011

Thanks all!

It ended up being the oil pressure sensor as everyone said. Once I returned my defective Snap On GM oil pressure socket.. ya, the original one wouldn't fit the sensor and turned out to be the first defective socket my 30 yr. vetern Snap On dealer has ever seen... lucky me, eh??!!

Anyways, checked the pressure with the mechanical test gauge and determined my dash gauge reads about 8psi high. Didn't leave it on long enough for the car to warm up, just wanted to make sure all was good... and it was.

Glad that's over. Next step, new rubber to replace my 2002 mint Goodyear F1's... (well, the fronts anyways)

05-13-2011	#1
maxxpower Join Date: Apr 2011 Location: Guelph, Ontario Posts: 9	Low Oil Pressure.. Hi All... It's been a while since I've been on the forums as unfortunately my '91 ZR has set idle for the better part of 2 years as life and building a new house got in the way. However it did get a little run time shuttling it from here to there. All I can say is, with as crazy as things have been the last couple of years, thank goodness the car always started, ran perfectly and never gave me a moments concern! Thank you Marc!! Anyways, I had the car out yesterday getting my emission test done (had to put cats on it first) and when coming back I was flogging it a little bit (as I always do) and the LT5 didn't miss a beat, pulled strong, felt and sounded great! But, a few miles down the road I noticed the oil pressure about a 1/3 of what it normally is and when I slowed to an idle the pressure gauge went hard to 0! The gauge wasn't erratic at a steady rpm, but wasn't completely solid as it has been in the past. There was also no strange noises or warning lights, so I basically didn't let it go to an idle again and limped home where it sits now on the hoist. I had a good look and didn't see anything obvious so I pulled the oil drain plug figuring an oil change couldn't hurt anything and left it. I have run Amsoil in it since new and the oil always looks good coming out. This time was no exception, all looks normal. The car has 36K kilometers (23K miles) on it, most of them a 1/4 mile at a time. I don't know if the few runs to 7K had anything to do with it or if this was just a coincidence? I was just wondering if there is a common item that others have had the same condition with or any thoughts as to what might be wrong... oil pressure sensor, switch, oil pump bypass stuck?? Thanks... Greg

05-13-2011	#2
gbrtng Join Date: Feb 2006 Location: San Antonio area Posts: 1,179	Re: Low Oil Pressure.. Change the oil pressure sensor - it's behind the filter - common failure. __________________ “Buy the best example of what you want, and pay whatever it takes. That way, you cry only once.” ~ Bruce Meyer

05-13-2011	#3
maxxpower Join Date: Apr 2011 Location: Guelph, Ontario Posts: 9	Re: Low Oil Pressure.. That's what I'm hoping for, I've already picked up a new sensor and will try it on the weekend if it ever stops raining here. : ) Thanks for the reply!

05-13-2011	#5
GOLDCYLON Join Date: May 2007 Location: Peoria, AZ Posts: 9,155	Re: Low Oil Pressure.. And welcome to the forum __________________ GOLDCYLON - 91 ZR-1 #2014 GOLDCYLON - 90 ZR-1 #2794, 4L60e (Formerly Schrade's) GOLDCYLON - 11 CTS-V Arizona State Director 91 WHITE/BLACK #2014. 380 P&P&PCed,Ported Heads, Jeal Long tubes, Corsa Exhaust/FIKSE FM-5s /LED TLs, LED Headlights, Front Wilwood 6 piston narrowlite calipers and rear Wilwood caliper street shop mod,CNCed Coolant Pipes,TPI Cvr,Filter cover,Stainless Bolts, DRM/DOM PROM /ZFDOC mod build #102,DRLs,BMAD with stainless Debris Screen,Coplan Air Blaster, Pioneer APP Radio 4,Brey-Krause HB,Sub Bar,Fire extinguisher seat mount,DRM Coilovers,LEDs everywhere,Compass mirror (orange),V1 DIC hidden display, Homelink sun visor, Carbon Fiber top x3 and APSIS Carbon Fiber interior, APSIS CF Steering Wheel/NAPA Leather, Banski trailing arms, Guldstrand front suspension,urethane bushings from Prothane (total suspension) ZFDoc drive shaft safety loop, raptor shift light (orange),AO engineering louver front plate, Console seat cushion, 96CE seats with black custom Sheepskins, ss billet catch can,Viper remote entry/alarm,Cragar Rear Louvers,LED side louver lights, Dewitts Radiator with SPAL fans and a Woods 160 T-Stat 90 RED/BLACK #2794. 4L60e Automatic Stage V by RPM Transmission, TCI Dedicated TCM, OBX Stainless Headers, Corsa Exhaust, SAN Secondaries and Haibeck PROM, Exotic Muscle Coil overs, LED Interior Lights, LED Tail Lights, LED Headlights, 94 Sport seats with black custom Sheepskins , Cragar rear louvers, GS Front calipers, Banski Trailing arms, APSIS Carbon Fiber steering wheel, Front and Rear Baer Eradispeeds, DRLs, Guldstrand front suspension,urethane bushings from Prothane (total suspension), Dewitt's Raditor with Dual SPAL fans and a Haibeck 170 T-Stat 11 RED/GREY CTS-V

05-13-2011	#6
maxxpower Join Date: Apr 2011 Location: Guelph, Ontario Posts: 9	Re: Low Oil Pressure.. Thanks to you also Goldcylon! In fact on my travels to the dealership to pick up the sensor, I met up with my Snap On dealer and got one of those deep sockets along with a new oil pressure test kit. Although I am new again here, I was once a more active member as I have been a member of the ZR1net registry since the beginning (member 126) and the ZR-1 net before that, and the ZR1 Owners before that, etc. Anyways, looking forward to the summer and new found time to enjoy it!

05-14-2011	#8
xlr8nflorida Join Date: May 2008 Location: USA Posts: 1,096	Re: Low Oil Pressure.. Agreed, that is a 10 Minute job and $20 fix. I had the same problem about 10 years ago.

05-16-2011	#10
maxxpower Join Date: Apr 2011 Location: Guelph, Ontario Posts: 9	Re: Low Oil Pressure.. Thanks all! It ended up being the oil pressure sensor as everyone said. Once I returned my defective Snap On GM oil pressure socket.. ya, the original one wouldn't fit the sensor and turned out to be the first defective socket my 30 yr. vetern Snap On dealer has ever seen... lucky me, eh??!! Anyways, checked the pressure with the mechanical test gauge and determined my dash gauge reads about 8psi high. Didn't leave it on long enough for the car to warm up, just wanted to make sure all was good... and it was. Glad that's over. Next step, new rubber to replace my 2002 mint Goodyear F1's... (well, the fronts anyways)