Oil Pressure Gauge issue

[grimm]

I've searched around the forums but I didn't find anything exactly like the issue I'm experiencing.

So within the last couple of days, I've noticed that my oil pressure gauge will drop to zero. However, under normal acceleration or steady speeds, I will get an average 40-60 lbs on the gauge, at a complete stop it will hover around 18 lbs. Sometimes heavy braking will dip it to zero, sometimes heavy acceleration will dip it to zero, and sometimes it's just random. I don't get any check engine light, or check gauges light (which I know both work).

So am I lookin at a potentially faulty gauge or relay? Does this happen when oil levels are below what they should be? Or am I going to have to prep myself to replace the oil pump.

Thoughts please. If you need more info I can try to provide some. Thanks

 

[fowldarr]

I'm having the same problem. Don't have an answer, but I'll be watching this thread for the genius with the right answer

 

[grimm]

Well, I'm going to start by checking oil level and quality and take it from there. I'll post any updates. Meanwhile, if anyone has any advice or ideas, feel free to chime in.

 

[Siler5]

I have a 2003 Tahoe and had eratic guages I took it to the dealer and they told me that the whole guage cluster needed to be replaced it is covered under a chevy warranty and will cost $100 and the warranty is good up to 100,000 miles after that it will be more like $500. The symptoms vary from dash lights going out and different guages sticking and not reading accurate. Thats my two cents.

 

[fire730]

The OP has a 97 listed in his sig. The NBS are the ones with the cluster problems.

I have never seen an issue on an OBS cluster. I would just start with replacing the sending unit or at least checking the plug and wiring to the sender.

 

[99_2door]

what should the gauge be reading normally? at idle, under load, and cruising?

 

[97srad750]

Could be the oil sending unit. Although it wasn't my problem when mine did something similar, and that was the suggestion I got. I changed the oil and put a heavier weight oil in it and it was fine.

If you are scared about it I'd get a pressure reading. It could be the oil pump

 

[grimm]

My repair manual shows that 18 psi should be the minimum at idle. Which is about what it shows (18-22 psi at idle). I'm getting the proper amount of pressure at idle, under load, and at cruising speeds, as well as the initial cold start, so I think the oil pump is functioning normally.

I checked my oil, quality looked fine, but level was a little low, which may be the culprit. I'm going to pick up some oil and a filter and do an oil change after work and see how that goes. I suspect this will help the issue. I'll keep you posted.

 

[moviewithnotitle]

I have had this problem for years on my 96'. It's normally an indication of "slightly" low oil level. Read this as less than a 1/2 Qt low. After an oil change my gauge reads fine for a while until a couple of issue kick in and the oil level drops slightly.

I have had two issues with oil:
1st - I get blow-by when towing my boat. The boat is about 4800lbs with the
trailer. Under heavy acceleration I get this.
2nd - I had a leaky oil line into the radiator on the motor side. my Mechanic picked it up and after that was replaced, this have been good for about 6months now. But the guage still 'dances' when I am nearing a oil change.

I'm fine with this as long as it stays stable during normal operation, which it does.

Switching to synthetic didn't make a difference as I have been using Syn for about 6 years now and it's done this all along.

 

[97srad750]

My repair manual shows that 18 psi should be the minimum at idle. Which is about what it shows (18-22 psi at idle). I'm getting the proper amount of pressure at idle, under load, and at cruising speeds, as well as the initial cold start, so I think the oil pump is functioning normally.

I checked my oil, quality looked fine, but level was a little low, which may be the culprit. I'm going to pick up some oil and a filter and do an oil change after work and see how that goes. I suspect this will help the issue. I'll keep you posted.

Add a little oil and see what happens. The only true way to get an accurate pressure reading is with a mechanical gauge. I suspect you're fine.

 

[grimm]

Thanks for the input guys. I'll post an update when the oil is changed, the filter replaced, and everything at proper levels.

 

[grimm]

Sorry to bring back my old thread, but I figured it would be good for someone else to know if they see the same thing. My oil pump is fine. The sending unit ended up being okay as well. I change the oil and filter and made sure I was at the proper levels and the problem has stopped. As it would turn out, I was just a little low on oil. If your oil pressure gauge dances around, try the simple solution first. It may not be as big of a deal as you think.

 

[crmzendrgone]

I have the same but opposite it redlines and even further as seen in the image I posted on the temp gauge thread. I have done mulitple oil changes and no change i have not check with a manual guage yet but when I get free time I will try that. HOPE IT ISN't the pump.

---------- Post added at 07:36 PM ---------- Previous post was at 07:36 PM ----------

here

http://tahoeyukonforum.com/forum/showpost.php?p=203264&postcount=5

 

[grimm]

Hmm, that one almost seems like a faulty gauge or sending unit, but I can't be 100 percent sure. Manually check you pressure to see if its within spec. If so, then you're alright and just have a false reading.

 

[crmzendrgone]

What is the specs

curb idle and 3000 rpm???

Anyone have an idea what the psi should be at those rpms?

 

[grimm]

I'm not 100 percent sure if this applies to the older TBIs, but I would imagine so. According to my manual :

-Cold start up should be around 45-60 psi, in all rpm ranges
-After warm, you should be seeing a minimum pressure of 18-22psi at idle.
-Under load should be around 45-60 psi, once again
-Cruising should warrant about 40-45 psi.

If you check you pressure manually and you get roughly those results, you should be okay. Maybe someone with a pre-96 truck will chime in with more info, just in case the specs are different for the TBIs (I don't see why they would be though)

 

[crmzendrgone]

Cool THANKS!!! at least it is a guide line to follow.

 

[faze]

In my 95 my guage cluster did start to go and my OP was the first guage to act badly...in my case it was either reading correctly or too high.

The guage cluster didn't seem to surprise the part guy at my gm store...rather than drop 500 on a new one I just put in a mechanical guage.

After a while my volt meter began to read low as well.