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2006 Trailblazer LS EXT 4WD
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Discussion Starter · #1 ·
Have found this site to be a wealth of information! I have a 2006 Trailblazer LS EXT 4WD wit 257, 000 miles. Through the information here I have learned that the indicated oil pressure is a computer fantasy. I have an issue with a fluctuating oil pressure. My daily drive is a 140 mile round trip. The pressure is fine (40plus) until I get to the first stoplight about 25 miles away. The pressure drops to zero as soon as engine RPMs drop the idle. A little pressure on the gas pedal and up it comes. This is very frustrating and I am checking oil levels daily or every other day. Seems to losee a bit over several weeks (also have oil in the intake box) but I keep up with it.

Is there any way to get an accurate pressure reading?
 

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2004 chevy trailblazer_lt
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1,117 Posts
Welcome to the Forum!

Well, the only way I know of is to get a mechanical oil gauge and plumb into the engine to see what the oil pressure actually is.

Good Luck!
 

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2004 gmc envoy_slt
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2,589 Posts
It might be a matter of a weak oil pressure switch or you actually do have low oil pressure at idle. Changing the switch should give you an answer.
 

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2002 chevy trailblazer_lt
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1,112 Posts
Installing an old school aftermarket oil pressure gauge helps for peace of mind. Knowing the true oil pressure is useful. Also, this may come as a shock to some but the stock oil pressure switch cycles at about 3 psi!!

57171
 

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Hmmmmmmmmmm... you might need to get the oil pressure gauge for my 1956 Case VAC/VAN tractor.

It runs at 10# at full throttle and idles at 3#.

The gauge sweeps a whole 270° from ZERO to 15 lbs.
 

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2005 gmc trailblazer_ls
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163 Posts
Most likely this is a cause of the failing oil pressure switch. It may also starts leaking small amount of oil at the connector. If you decide to replace it go with OEM. Do not buy after-market they don't work well. Had the same problem.

Sent from my SM-G955U using Tapatalk
 

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2008 chevy trailblazer_lt
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10 Posts
I replace my oil pressure switch about once a year! It always plugs up then drops to zero. Just put a new one in a week ago actually
 

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2006 Trailblazer LS EXT 4WD
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2 Posts
Discussion Starter · #8 ·
Out of curiosity....besides at the pressure switch at the filter housing is there another place on the 4.2 I6 where a mechanical guage could be tapped in?
 

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2002 chevy trailblazer_lt
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Out of curiosity....besides at the pressure switch at the filter housing is there another place on the 4.2 I6 where a mechanical guage could be tapped in?

Sure is.. several actually but this is the favored spot....

57195
 
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