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Oil Pressure and Mileage

Old 01-18-2014, 05:43 PM
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Default Oil Pressure and Mileage

Hello. I have 2 questions that I would like to ask. I have a '95 Blazer with 250,000 miles. It runs well. My concern is that my oil pressure gauge reads 40 when I'm driving and drops to 22 or 24 when I come to a stop. My oil level is fine. Is this normal or is the oil pump going to fail? Also, a few months back I had the spider replaced. The Blazer runs smooth but my gas mileage is terrible. I'm getting around 12 to 14 miles per gallon. Can I adjust the engine so that it doesn't run so rich or is there a smarter way to fix this? Thank you.
Old 01-18-2014, 05:56 PM
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Both of my blazers did the same thing with the oil. My 4 door likes to start a little over 40 when its cold then as it warms up the pressure decreases. Seems to be pretty normal though. I just did an oil change and its still doing that.
Old 01-18-2014, 07:08 PM
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Mine has done that since I bought it with 50k. Now has 210k.
Old 01-19-2014, 01:59 AM
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O.K. I feel better about that now. Thanks for your answers. Now to see if I can do something about the gas mileage.
Old 01-19-2014, 09:25 AM
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Yup pretty normal... these engines don't produce much pressure at idle. Just like everyone else said, mine starts over 40 and drops down around 20 once warmed up at idle.

When i rebuilt the engine in my 97 i installed a high volume pump... that thing would peg the gauge cold and run around 40 hot idle. Might sound like a good thing, but that engine started leaking oil from everywhere after about 10k, i always figured the pressure was just too high...

As a rule of thumb, as long as it doesn't get below 5-10 at idle and increases with rpm you should be fine. Remember the stock gauge probably isnt too accurate anyways.
Old 01-19-2014, 12:28 PM
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thats fine. my daily driver idled at like 10 for a while. i eventually put in some lucas oil stabilizer stuff in there and its been at 20 since, even after a few oil changes. it may have just cleaned out the sending unit but id rather look at the 20psi then 10 any day
Old 01-25-2014, 10:25 PM
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Yup yup. It is common. Both my 2000 LT (sold it) did the same thing and so does my 2004 I just bought last week. Started at around 45 and once up to operating temp...drops to 25 at idle and 40 driving. I was wondering the same thing with my old one. But, once I got this one and saw it doing the same thing... I was much more at ease.
Old 01-26-2014, 12:51 AM
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your fuel mileage thing could just be the "winter blend" fuel... i always seem to get worse mileage in the winter and i live in southern cali where if you want snow, you have to drive to the mountains. just the gas companies making more money for no reason.
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