2005 Chevrolet Monte Carlo- High reading leads to conflict

Took my cream puff 2005 Monte Carlo (only 42,000 miles) to dealer for oil change, tire rotation,and premature transmission fluid change.—Oil pressure gauge was reading properly on my way in because I eyeballed it as I normally do with my readouts…On my way out, gauge read “high”. Before I left dealer, I notified Service Advisor. He said “drive it” and see if it self-corrects. I did; it didn’t.—Dealer has not accepted blame. If I need new gauge, estimate is over $600 because whole instrument cluster must be removed from dash. If only sending unit needs to be replaced, estimate is still outrageous at over $300…—Gauge was fine going in, broken coming out.Dealer says he is not responsible: I say it sure is one heck of a coincidence that the gauge broke while the car was in his shop.—Do you think that a service tech might have inadvertently pulled a connection or some such thing?

My guess it is your sending unit rather than the gauge, check that. Unit is around $12.
Did you check your oil level?


If the gauge reads high… why do you think the gauge or sender are broken? You may have a bad filter, a stuck relief valve, they put in too heavy oil…

Until you answer the question, you can’t assign blame OR, more importantly, fix the car!


The oil filter that was installed may have a stuck by-pass valve.

Try replacing the oil filter.


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This is quite easy to diagnose, provided the shop . . . I’m assuming this was a Chevy dealer . . . uses the factory scan tool, or an oe-level aftermarket scan tool

You hook up the scanner and select instrument cluster

then you choose functional tests

Then you choose “sweep gauges”

If you’re able to properly sweep them up and down, you know the cluster itself is fine

then you can hook up a mechanical engine oil pressure gauge and measure what the actual engine oil pressure is

Next you take a closer look at the engine oil pressure sensor

Personally . . . and based on professional experience . . . I doubt you need an instrument cluster

by the way, if the gauge is faulty, you do have options besides replacing the whole cluster. There are companies out there that repair your cluster . . . by soldering in a new stepper motor. A stepper motor drives each gauge. This is how it works. You bring them/send them the cluster and they fix it and return it to you. the good thing about this is that there’s no reprogramming involved

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