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. :mrgreen:

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

Re: Low Oil Pressure..
 

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

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!

Re: Low Oil Pressure..
 

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

Re: Low Oil Pressure..
 

;) And welcome to the forum

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!

Re: Low Oil Pressure..
 

We both learned that lesson....;)

Re: Low Oil Pressure..
 

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

I had the same problem about 10 years ago.

Re: Low Oil Pressure..
 

change the oil filter. the first oil change i did I used a fram filter and the oil pressure was lower then what it was with the filter that was on the car when I bought it...not sure what that was but since the original owner didn't do anything to the car himself I'm going to assume it was a gm filter. Changed the filter the next day and the oil pressure was back to where it should be.

Re: Low Oil Pressure..
 

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

Re: Low Oil Pressure..
 

Mine gauge started pegging off the scale- kind of an erratic flutter sometimes.

same sensor issue? I do have the socket (haven't used it in 15 years).

Re: Low Oil Pressure..
 

Yes. And Yes it one of those tools that stays in the tool bag that you only get to you a couple of times in a single lifetime lol

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)