nosnow

Basically, I purchased a new oil pressure sender for my 86.5 because my oil pressure gauge was not giving me an accurate pressure. When cold it would be at 5 bar but when warm it would stick at 3 and then jump to 5. I know warm oil causes oil pressure to fluctuate, the issue was that it wasn't reading in a smooth fashion and it was sticking.

I cleaned the oil diverter valve of all the oil sludge and put it back together as it came out installing the new pressure sender. I started the car and waited, the guage went up to 5 bars. I went for a test drive and no matter how warm the car got during idle the guage always showed 5 bars. Now if I turn the ignition to the "on" position the guage goes to 5 bars. I attempted to switch the wires but then the gauge went to 5 bars and stayed there even when the key was not in.

So, opinions please.... Did I put together the diverter valve incorrectly? Is the new sender a dud? Any other things I should look at?

joejoe

Sounds like the guage itself is sticking. Have you tried hitting the pod to see if needle drops? Have you checked the plug one the cluster itself?

IcemanG17

The typical failure mode of the pressure sender is to read 5 bar all the time...hot or cold.....normal is to be pegged at 5 bar when cold then slowly drop to somewhere above 2 bar at idle when warm...that quickly pegs at 5 bar at higher RPM's.....

Also when you change the sender also get the 2 springs that go above it....as they age a get weak it will cause hot restart low oil pressure and can contribute to warmer running temps

nosnow

It was a bad pressure sender. All fixed and working perfectly.

linderpat

can you post the process to fix/repalce? Mine has read at 5 bar the whole time I've owned it, and this has been on my to do list for awhile now....

ROG100

Ed,
If its pegged at 5 it means the sender is toast.
Just unscrews and replace and the wires need re-attaching.
Very straightforward.
Roger

leperboy

Can't it also mean that the wires are connected to the wrong posts on the sender? I think I've read a few cases where PO's have done this.

I would first switch the two connectors, see if that was the problem. It only takes a couple minutes.

Matt

nosnow

I used the following instructions

http://members.rennlist.com/v1uhoh/oilp.htm

The real problematic part is getting the sender seperated. While you are in there even if the upper housing stays you should take it out clean out the sludge and replace the springs. Remember to get all of the crush rings for this project there are two; one on the sender and one for the housing. I got everything from Roger.

nosnow

If the wires are crossed the needle stays pegged at 5 even with the key out of the ignition. That was my initial thought.

linderpat

thanks guys (and sorry for the hi-jack!). I'll do this job at next oil/filter change at the end of the driving season. Seems like removing the oil filter is the best way to go...BTW Paul - love the blue 86 - looks familiar

Mako 928

You can remove the oil filter without draining the oil. A little oil will spill out from the filter but thats it. Not having a gage that reads properly is very unsettling. Ask me how I know!