Zoidman

Hello Everyone, sorry for the story that I'm about to write, but please help my diagnose the 0 oil pressure reading. I'm listing all the events I can recall to help with providing the clearest picture possible.


This weekend I took my C5 for a drive in the mountains on an extremely windy road (something like a Go-cart track for cars), but at the very top of the road when I started to slow down and check my gauges I started to notice the oil pressure gauge was going nuts!

The gauge was dancing around then dropping quickly, soon the Check Engine light popped on and the car started digging in warning, and eventually the gauge dropped to zero. I pulled over immediately and shut the car down.

After letting it sit a few minutes I decided to check it again and the pressure was reading zero still. I had noticed before the car was stopped that the oil pressure reading was strongly related to the RPM's of the car (when going around the last few turns). Also I did not notice any sounds or noises out of the ordinary with the engine, and the engine temp stayed consistently around or below 220 degrees.

Now I'm stuck WAAAAY out in the middle of nowhere, in an extremely obscure mountain road and have to get out (reads No cell phone). So I crank over the car and do a test with the RPM's and again notice that with increased RPM's the pressure does go up a little, so I hold my breath and start driving. I shift into a low gear and keep the RPM's up and after a minute or two the oil gauge pressures return to normal and drive the rest of the way back home.

The next day, the car acts more or less normally except that the Oil pressure seems to read and stay a little higher than what (I think) it should be, and takes a lot longer to normalize to around 40 PSI.

When accelerating to freeway speeds with a cool engine the Oil Pressure gauge goes up to about 62 and takes about 10 miles to drop down to around 40 PSI.
With a warm engine at a stoplight the PSI's dropped as low as 26PSI but typically hover a little higher (29 to 32 PSI).
The PSI has not gone any where near 0 again since that first incident on the mountain, and I've been watching it very closely.

I took it the same day to a Corvette specialty shop. The guy hops into the driver seat and at a park rev's the engine to see how the oil gauge readings respond. His diagnosis was that the oil sending unit is going bad. He said this is because the gauges response to engine RPM changes was laggy and slower than it should be, which is a sign of a failing sensor.

When I bought the car in early april of this year it had a bad oil sending unit, pegged out at 130PSI, I replaced that with a BW Sending unit and after that all seemed well.

Now here I am about 4 months later and I'm seeing this issue? Any ideas?


Thank you everyone for help!

Zoidman

I think my options right now are to throw some money at it and replace the Oil Sending Unit again, which isn't cheap (Corvette shop quoted me at 300 bucks for parts and labor) to hope that fixes it.

Or preemptively replace the Oil pump, which is very expensive (around 1200 for parts and labor)... and 400$ more for a new cam because why not? I'm already there lol.

Another options I've been thinking about is getting an oil sender relocation kit with a mechanical gauge on it to make it much cheaper in the future to replace the oil sending unit.

This of course lets see the actual PSI of the engine regardless of the electrical unit, but again, I don't want to needlessly throw money at the car. The kit's I've seen for relocation are about 240$, and then add the cost (300$ish) of the sensor and labor to install the whole thing. That's almost half the cost of just just replacing the oil pump.

Again I ask, what does the mighty Corvette Forums hive mind have to say about this issue?

3boystoys

Test the oil pressure with a MECHANICAL gauge first.

Smoken1

Read this thread 52.00 to relocate the sensor if you want a gauge its a little more
http://forums.corvetteforum.com/c5-t...post1586674601

Boss75

Have you checked your oil level?

65GGvert

An oil pressure sensor is around $40. If you use one of the three methods available on this forum, the labor is free. Make sure you really have oil in the pan. Check the oil pressure with an external gauge. Not necessarily in that order.

Zoidman

The oil level is where it should be on the upper side of the good level. No leaks around the car, and the engine is clean (no sign of oil leaks) as far as I can see, although I did note the radiator fluid was low.

I forgot to mention that the day before all this happened I swapped out the AC and Drive belts with new Gatorback belts, but I don't think that would matter.

Does anyone have a part number or a link that I can use to order a pressure gauge to check? One of the threads I read about a similar problem was a guy who couldn't figure out how to hook the gauge up to his car, something about a wrong sized adapter, and I want to make sure I get the right one.

Catman58

I agree with 3boystoys test it with a mechanical gauge

runner140*

Thanks, I couldn't find it.

Zoidman

I have all the parts picked out and ready to order, but I don't know what mechanical gauge to get for the inline kit.

Does someone have a part number or link for the inline gauge?

3boystoys

Any oil pressure gauge will work, I think on the LS1 there is an oil port near the oil filter. Try search on the site here to find it.

OR

http://www.thirdgen.org/techboard/lt...echanical.html

See post #6 for a pic.

OR you might want to watch this:

Zoidman

What I am trying to do is something like this http://www.dpecorvettes.com/gpage7.html
Where the gauge is built into the extension kit, but I can't seem to find anywhere that lists the part number for the gauge or the t-junction.

I was able to find this T-junction http://www.summitracing.com/parts/var-92846/overview/ PN: VIAIR Multi-Port Fittings 92846

Would that, combined with say, this oil pressure gauge And put inline with the rest of those fittings linked earlier work?

Specifically I think the T-junction would fit between the EAR-64191914ERL, and the SUM-220121 with the oil pressure gauge coming out of the top of the junction?