Heyy guys, saw someone with an 88 that had this problem, wondering if you could help me send an answer. Thanks!

a while ago, my oil pressure sender went bad. so we bought a new one. but the gage is still reading no, or very low oil pressure and it usually comes up when the revs. go up and then falls back off. we (my dad and i) know that the engine has pressure because when the same engine was in the other car it was fine; and i just drove it and it didnt die. could it just be a wiring problem, or something else? if anyone has any suggestions, they'd be very welcome. its an '88, no turbo, just incase you were wondering.

-thankx

 

The gauge may be broken. This is very common. Verify pressure with another gauge.

 

Try an aftermarket CHEAP mechanical gauge like a SunPro. I bought one of these a few years ago for maybe fifteen bucks or so. It confirmed that the oil pressure was good and it was a sender/gauge problem (stockgauge that is).

There is a slight problem finding the right fitting for an aftermarket gauge to fit the stock hole. I've done this several ways. One way is to cut the mushroom part of the sender off and drill and tap the proper threads inside the leftover part of the sender that will be the same as your aftermarket gauge. Then just screw the original sender threaded part into the block.

Another way is to remove the banjo bolt that connects the oil cooler return line to the rear side housing. Drill and tap the proper threads for your aftermarket gauge into the center of that banjo bolt and reinstall.

SummitRacing, Pegasus, JEGS etc sell adapters. I think 1/8 BSP are the threads in the block. You might check that out for accuracy. Do a SEARCH on this forum for 1/8 BSP.

I'd bet your oil pressure is fine and dandy. That sender cost a bit? eh?

A jpg of the SunPro with the home made adapter made out of the OLD stock oil pressure sender (mushroom cut off....drilled and tapped bottom half).

I couldn't find my drilled and tapped banjo bolt. It's out there somewhere.

And the SunPro IS acccurate. I checked it against my Fluke PV350 transducer (another good way to check oil pressure). Plenty good and fine readings.

 

Here's another jpg but al little different. I show the oil sender and try to show where I cut the boss off it and then drilled and tapped the remainder. An example of the finished product is shown also.

Also shown is the banjo bolt I referred to. I can't find my drilled and tapped one but it looks similar to this one.

See the BLACK item? Square in shape? Its the oil sender CONDENSER. This item was originally bolted to one of the clutch slave cylinder bolts and HAD a single wire on it. Yellow/red in color I THINK. So what I did was remove this item. Then I put a resistor of serveral K ohms in line with the wire that was connected to this condenser and gnded the other end of that resistor. Anyway I tried several different values of resistor til I came up with a combination that made the gauge read fairly accurate at idle AND 3000 rpm. Just something to do on a slow day.

 

If you have a gauge that shows somewhere around thirty/forty lbs at 3000 rpm and the engine is fully HOT, when you hold it at 3000 rpm, I can make a jpg of how you can couple a couple of resistors and tie it to your oil pressure condensers wire so the gauge will show more accuratly. It helps to actually KNOW that your pressure is really good and the gauge is the culprit causing the low showing.

IF you find the pressue is actually low, then I wouldn't do what I'm suggesting above.

 

Thanks for the info!