How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Pete Your Own Question
Pete, Technician
Category: Car
Satisfied Customers: 29057
Experience:  17 years automotive training and experience.
Type Your Car Question Here...
Pete is online now
A new question is answered every 9 seconds

I have a 2005 Tahoe with a new oil pressure. The oil still

This answer was rated:

Good afternoon. I have a 2005 Tahoe with a new oil pressure. The oil still has nearly half life and is filled. Still have oil pressure warning signal dinging.
JA: How old is your oil pump? Has the check engine light come on?
Customer: I understand the oil pump is fine...But i can check. The dealership didnt mention it
JA: Are you fixing your Tahoe yourself? What have you tried so far?
Customer: No I paid a mechanic to change sensor
JA: Anything else you want the mechanic to know before I connect you?
Customer: I also have read maybe my idle RPM is too low ??

Hi my name is ***** ***** I will be happy to assist with this today.In some cases I may need more info to assist better.I apologize for any delay.

Does your model have the engine oil pressure gauge and if so is this gauge reading pressure and if it is what is the pressure at idle and revved up?

Let me know so we can continue,thanks Pete

Customer: replied 7 months ago.
Thanks, Pete
Yes- It reaches the 40psi mark when revved, however, when the car is in idle the pressure drops to around 10. The tac drops to under 500
Customer: replied 7 months ago.
While you think, im going to crank up and read again and come right back

Unfortunately I am unable to place a call on this here myself but others see you have requested a call and may still call on this here.I can however continue here.

If you bump the throttle to around 700 or 800 rpm.Your oil pressure should be in these ranges:

Oil Pressure - Minimum - Hot
...................... 41 kPa at 1,000 engine RPM (6 psi at 1,000 engine RPM)
.................... 124 kPa at 2,000 engine RPM (18 psi at 2,000 engine RPM)
.................... 165 kPa at 4,000 engine RPM (24 psi at 4,000 engine RPM)

Since you are dropping to the 10 psi at 500 rpm this is within range but the gauge may not be fully accurate at 10 psi.If you have not had a manual engine oil pressure test done this should be done.If there is an issue with the actual engine oil pressure this will need looked into and repaired as soon as possible as low engine oil pressure will damage the engine internally.This can be a plugged up pick up tube or sludge build up or even worn engine crank or cam bearings or an issue with the oil pump itself.

Since the alarm is going off the computer still sees an engine oil pressure issue and the sensor is o.k. as it was replaced and the gauge is working so this usually does indicate an internal mechanical fault.

If more help is needed, use the reply tab to continue our conversation. If no further assistance is needed, kindly rate my service,your 5 star rating is appreciated.You can rate at any time and we can continue to work on your question as this will not close out your question.Keep in mind in some cases it can be difficult to fully diagnose or help repair your vehicle without seeing it and I work on delivering the best possible answer from what I see to work with.

Thanks Pete

Customer: replied 7 months ago.
ok thank youI just checked the gauges again.It is reading an idle of about 700 and 20 psi on the guageI have to rev to 3000 to see the gauge reach 40When hot and on the road the idle drops and so does the pressureNot sure if this is related but a couple of things i've read say it may be the intake filter or intake gaskets..?
Cluster failure?The dealer performed a diagnostics report which did not mention any of the aforementioned items
Customer: replied 7 months ago.
The engine currently sounds and runs very well

Your welcome

If the engine sounds good it is very possible this is the instrument cluster at fault.The oil pressure message should go off at 10 psi or above here.To be safe I would ask the dealer if they did or can do an engine oil pressure test to make sure it is o.k. mechanically.If it is o.k. then the cluster does need to be either sent in for repair or removed and replaced then programmed by a dealer.

Let me know if you need anything else and feel free to rate my help here as this is how I receive credit for my time.Your 5 star rating is appreciated

Thanks Pete

Customer: replied 7 months ago.
ive called the dealership and awaiting an answerIf it is the cluster - would the gas gauge also be affected? Because my gas gauge does not read accurately (showing full or empty arbitrarily)bot***** *****ne: based on what we've discussed, I should pursue the cluster repair (or replace) and programDid we eliminate the other possibilities in the analysis (dirty pick up, intake filter and gasket)?
Customer: replied 7 months ago.
actually - I just read report. "Oil pump is working as designed"

The gauges each have their own stepper motor to operate the needle so when one gauge is acting up the others will operate properly.The gas gauge issue is due to a faulty fuel level sensor in the fuel tank.This was a very common issue with the sensor needing replaced.

Since the oil pressure is going up and down on the gauge and is within range this does indicate the sensor and actual pressure are o.k. here.This leaves the cluster with an internal fault causing this issue needing replaced or repaired.

Thanks Pete

Customer: replied 7 months ago.
34;internal fault" in cluster
with an "internal fault" in the engine?

I apologize.Internal fault in the cluster itself.

Let me know if you need anything else and feel free to rate my help here as this is how I receive credit for my time.Your 5 star rating is appreciated

Thanks Pete

Customer: replied 7 months ago.
Haha - I guess you can tell I am no mechanical engineer!Thank you for your help!

Your welcome

Pete and 5 other Car Specialists are ready to help you