Skip the auto shop - Our mechanics make house calls

Q: My oil pressure gauge read high with lights on

asked by on

My oil pressure gauge reads a little over 40 normally but when I turn my headlights on, the gauge reads over 90 and I don't know why..can you give me some advice on how to fix this problem?

My car has 280000 miles.
My car has an automatic transmission.

The oil pressure gauge uses a resistance sensor to supply the oil pressure reading from the engine’s actual oil pressure. The oil pressure sensor on these engines may leak and get oil in the connector and cause erratic readings on the gauge.

I would first replace the oil pressure sensor and clean the connector. Then see if the problem still happens. The head lights may somehow be feeding back into the instrument cluster. This would need extensive testing if that is the case by removing the cluster and checking all the grounds and connections of the connectors on the back of the cluster.

Also, all the headlight grounds will need to be checked. There are two grounds to look at. One on the back of the cluster and the other on the instrument panel frame behind the instrument cluster. Check both these grounds to see if one is loose or broken.

If you need some assistance with these checks, get some help from a certified technician, such as one from YourMechanic. One of our mobile technicians will be able to come to your home or office to diagnose this electrical issue and help you fix it accordingly. Best of luck.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  1. Home
  2. Questions
  3. My oil pressure gauge read high with lights on

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Rough idle and smoking issue

Hello there, many faults will cause your 1999 Dodge Durango to have a rough idle and smoke. There are several different colors of smoke that can come from and engine. Grey smoke is typically oil, black smoke is unburnt fuel...

Q: Evap solenoid hoses routing

Hello. The EVAP solenoid is located in the top left of the engine near the throttle body. The hose for the EVAP solenoid should be in the same area. This hose is small and attached to other EVAP components. There...

Q: P0068? Runs rough and idles high

Hey there. This may be a sign of a faulty MAP sensor. The Manifold Absolute Pressure (MAP) sensor is a key sensor because it senses engine load. The sensor generates a signal that is proportional to the amount of vacuum...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.