Topic: Oil Pressure gauge reading incorrect

[kohr]

Well I tried the switch today and it is worse.

Normal when hot I was reading 40 psi idle and around 65 at 3000 rpms

1st switch went bad because it was reading 20/40.
Tried a 2nd switch brand Duralast. Idle is 0.  1500 rpm it is about 15.  3000 it reads about 25.
Tried a 3rd switch brand borg warner.  It is doing the same as the 2nd switch.

I replaced the wire plug end as well.  It wire is loose I get max reading on gauge.  If wire is grounding it reads zero.

Engine is running fine.  I even had it dyno tuned while it was like this and they ran it close to 6000 rpms 30+ times while on the dyno.

The engine is not the stock engine.  It is a pontiac 400 that previous owner got from proformanceunlimited.com.

Any suggestions as to what to try next?

[Trevon]

Just me...but sounds to me like there is nothing wrong with that 1st switch...  Cause if thats wrong...mine would be bad too, but I know mines working.  Just ran it today, cold it was almost 60 then got down to 20 or so at a temp over 110, rev it and it jumps to 40, I don't know.  Sorry if this response annoys you, just thinkin'.

[kohr]

Just me...but sounds to me like there is nothing wrong with that 1st switch...  Cause if thats wrong...mine would be bad too, but I know mines working.  Just ran it today, cold it was almost 60 then got down to 20 or so at a temp over 110, rev it and it jumps to 40, I don't know.  Sorry if this response annoys you, just thinkin'.

Well for the 1st 3 weeks I owned the car it always idled hot at 40 psi and and 3000+ rpm it would be 65ish.  Plus it does not explain why the other 2 would be 0 at idle.

I think I will go get a mechanical gauge tomorrow so I can at least work from a good number.

[Trevon]

Okay, didn't catch the part about how it was when you first got the car, my bad.

[gilbertsta]

Since we are on the subject.... I just put a second stock gauge in my car. It pegs the gauge the same as the first one.....Probably the sender .....I guess

[kohr]

Well this is turning out to last longer than I hoped.  I got the mechanical gauge today and decide I would take off the steel line (it is about 6 inches) that went from the oil filter area up to connect to the switch.  Well as I was trying to remove it the line got all bent up.  I then when to build my new line using transmission rubber hosing.  As I was putting the screw back into the oil filter housing it seamed the threads on the housing were stripped but it was hard to tell if it was just the thread tape (I also removed the oil filter to see better).  Either way I thought I had it all installed correct.

I finally got it all back together, started engine and everything seamed fine at first.  The mechanical gauge was working but then I had a leak.  I could not tell if it was coming from the filter or where the fitting went into the housing.  I was hoping it was the filter so I went to get replacement and it is a non stocking part so I have to wait until Wednesday.  I am using a k&n hp 2003 because of the nut on the bottom.  With the headers around it is difficult to get to the filter.

So my new question is what is the part called that I screw the oil filter into and it has the connection that goes to the oil sender?  If the leak is from where the line connects then I might have to replace that whole piece that bolts to the block.  Attached picture of engine has it circled in yellow.  The screw hole for the line is behind the picture view (you see it looking from back on engine).  I wanted to know the name of it so I can try and find one just in case.  I have been searching oil filter housing but nothing returns.

I am also now considering an oil filter relocation kit because it was already a pain to access the filter and if I have to replace this whole housing area then I might be good to do this as well for future convenience.

[eroc022]

thats the oil filter housing piece, usually those dont mess up but i guess anything is possible, might just be the gasket that is on it got torn or ripped?

[kohr]

I am redoing that area now.  Removing the housing,  adding a plate to block I got from tin indian performance that let's me relocate oil filter.  Oil filter will be relocated and I will have a mechanical gauge under hood and get the one in car fixed.  The shop that is helping is guessing the 1st sending was never accurate so they will match the ohm sending unit to what it reads off the mechanical gauge.

While it is in shop I figured I might as well get brake parts swapped out with my new ones.

[kohr]

Housing treads were completely shot which was the cause of the oil leak.

The gauge, even though it tested fine, does not work correctly.  It would require a gauge replacement to make it accurate.

I ended up getting a remote oil filter housing plate to relocate the filter from http://www.tinindianperformance.com/Pontiac%20oil%20filter%20housing.htm.  Unfortunately when you mount the plate and install the hose fittings you cannot install  the hoses due to the headers and near zero clearance.  I had to get the plate modified where they welded some aluminum tubing at 90 degree down in order for everything to clear.  The oil filter is now behind the front right running light.