C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

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Old Sep 14, 2014 | 02:17 PM
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I just bought my first corvette and I love it, it is a 1986. I had some major work done to it at a shop and now I have another issue. Whether at idle or driving my oil pressure shows fluctuation. It does not do it all of the time though. Sometimes it's stays at 80psi. Any thoughts? I could really use the help

Last edited by Barbara Wilson; Sep 14, 2014 at 02:20 PM.
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Old Sep 14, 2014 | 04:29 PM
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Barbara, i would think that the Gauge is may be incorrect. Check with the shop that did the work on it and ask what they may have done to cause this condition. What kind of work did they do that was Major? By the way, welcome to the Forum, you will find lots of help here....Many,Many Good People Here....
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Old Sep 14, 2014 | 05:05 PM
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Originally Posted by charliet615
Barbara, i would think that the Gauge is may be incorrect. Check with the shop that did the work on it and ask what they may have done to cause this condition. What kind of work did they do that was Major? By the way, welcome to the Forum, you will find lots of help here....Many,Many Good People Here....

The replaced the catalytic converter, replaced the intake gasket, slave and master clutch cylinders and did a tune up. I asked them what oil they put in and it was the very same that I use. I have done some research and read that it might be the oil pressure sensor. If so, is it hard to replace? Would love to be able to work on it myself
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Old Sep 14, 2014 | 05:08 PM
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I would change the sending unit first.
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Old Sep 14, 2014 | 07:06 PM
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Barbara, get you a Factory Service Manual also called FSM from ebay. It will have any and all info you require for do-it yourself type things..You can get the CD Rom that will help you pretty cheap....I don't think that the Sensor is hard to change, i just don't know where it is located on a 86. I have a 93...Charlie
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Old Sep 14, 2014 | 07:49 PM
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..... The oil pressure gauge sender is behind the distributor on the back of the engine ... it is the bell-shaped part with a single tab electrical connector ... the other sender is a fuel pump switch , it has two electrical tabs on it ....... You may be able to get at it with the distributor cap removed if you have small hands ........
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Old Sep 14, 2014 | 08:06 PM
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Originally Posted by We Gone
I would change the sending unit first.
This is a classic symptom of a sending unit and usually the problem. Easy to replace first and will probably fix it.

If that does not fix it, then a external oil pressure gauge should be connected to engine to measure the actual oil pressure. I would do this before I would ever replace the dash gauge and rip the dash apart.
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Old Sep 14, 2014 | 08:27 PM
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Originally Posted by Barbara Wilson
I just bought my first corvette and I love it, it is a 1986. I had some major work done to it at a shop and now I have another issue. Whether at idle or driving my oil pressure shows fluctuation. It does not do it all of the time though. Sometimes it's stays at 80psi. Any thoughts? I could really use the help
Nice car! These cars require a lot of tlc. Have fun with it.
Sam
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Old Sep 15, 2014 | 01:13 AM
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Originally Posted by Barbara Wilson
Whether at idle or driving my oil pressure shows fluctuation. It does not do it all of the time though. Sometimes it's stays at 80psi.
The oil pressure will show 80 PSI if the connector is not connected to the oil pressure sender. It sounds like your connection is intermittent. Check it out.

The oil pressure switch and oil pressure sender are located on the back of the block behind the distributor. The switch has a two-pin connector. The sender has a single-pin connector:



My intake manifold and heads were off when I took this picture, so your parts are going to be buried behind a lot of stuff...
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Old Sep 15, 2014 | 04:33 AM
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I would hold their feet to the fire because of the location of the sending unit. It could have easily been knocked loose or damaged by your shop while they were changing the intake gasket.
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Old Sep 15, 2014 | 06:50 AM
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First thing I would do is take it back to the shop and right then & there have them check the connector on the sender. It sounds to me like it is jiggling around a bit from engine vibration and just needs to have a solid connection. The fact that it sometimes stays on 80 is a sign that it is loosing it's contact.
Congrats on getting your Corvette and welcome to the forum.
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