Jumpy/high oil pressure

[motogman]

73 with an 86 mostly stock 3.2L.

I did not have the car on the road/running for a few years and have it going now. However, the oil pressure seems to be running higher than I remember. With some revs, i.e. max oil pressure, it reads up to about 140 on the gage.

Is this a problem to be real worried about?
What can be done to assess if it is sender or real?

I appreciate your help and comments.

[Flieger]

You might have the wrong sender. They went to a one with a different range of resistance and this will cause old gages to read wrong. Is it the sender from the 86 or the 73?

[motogman]

Flieger...

I am not sure 100% if the sender is from the original 73 or 86. My guess is it was in the motor and is the 86.

However, I don't think it did this or read high a few years ago, so I am not so inclined to think what I am seeing is because of the sender. However, you bring up a useful point. I have a couple of other cars which I could do a little swapping with to see if a different sender does the same thing. Then the question becomes ... how many different senders are out there, what are the differences, the part numbers and usage etc.

Ah... the rat holes we can go down once the contagion has set in....

I will do some more research but if someone has some references or listing of oil pressure sender usage... please share.

[Flieger]

Pelican shows one for 1965-1973
http://www.pelicanparts.com/cgi-bin/...%2520Each%2520

And three for the 1973-1989

http://www.pelicanparts.com/catalog/..._pg2.htm#item9

[motogman]

You are quicker than I on the research. Thanks

[Flieger]

I think I was getting confused on threads about people having the wrong temp sender for their gage, so I should have realized the pressure sender would be the 86 one. That is the part that moved from the fan side to the flywheel side I think. But I think there is still the issue that the gage needs to match the sender since there are different resistance ranges.

[edmayo]

What gauge do you have in the car, 0 to 5 bar or 0 to 10 bar (or 140 psi) now look at your sender (you'll need to remove it to see this) it will either be stamped 0 to 5 or 0 to 10.

[motogman]

Hi Ed...

I was hoping you would see this and comment. I have the 140 gage and the sender ... well I just went out to pull it and it looks like it is a 25mm to get it off but I don't seem to have one narrow enough. Do you have any tricks other than getting a 25mm shortie and grinding it thinner?

What I am really concerned about is if the higher pressure is something to worry about and what might cause it. I don't think it is a gage/sender miss match because it did not always have this problem and nothing has changed other than the pressure being measured.

Can you provide some overview of which motors used the 5 bar and which used the 10 and why?

BYW... I will send you a PM also.

[edmayo]

I use a 25mm 3/8" drive crow foot which I grind thin enough to grip just the hex of the sender, then an 8" or so extension and a long 3/8 drive ratchet handle to get me high enough to allow for ratchet handle movement and leverage. I think you'll find that your sender is a 5 bar sender if it's the one from the 86 engine. I think the 5 bar gauge started at least with the SC models, or maybe 77, not 100% sure. I'm not sure if possibly the problem has surfaced because of previous operation with the mismatched units possibly damaging the gauge. Either way you need to either change the sender to match the gauge or change the gauge to match the sender. If I have a doubt as to what the pressure really is then I use a mechanical gauge with a temporary hookup to compare the readings at various RPM levels.

[motogman]

Thank you Ed. I had a 1" crows foot and it did the trick. And yes... we have a winner. As much as I don't remember this being a problem in the past and don't remember changing the pressure transducer... Ed nailed it. The pressure sensor is a 5bar unit with a 10 bar (140 psi) gage.

Thanks Ed.