Marlon Targa 86

Had a great track day at Streets Of Willow, except:

During the 3rd session I noticed my oil pressure gauge was stuck around 2.5. No lights came on, engine temp was fine and had no loss of performance. I immediately went back to the paddock. Turned off the car and checked the car/engine:

- it had no oil leaking
- no smoke anywhere
- checked oil level and it was fine
- oil warning light was off

I decided to call it a day and started driving home. Started the engine, at idle the gauge bopping around at 1. When I rev'ed the engine, the gauge went back to 2.5. About a mile out the oil pressure was back at where it normally was, between 4 and 5.

I called my mechanic and he asked me to check everything again (oil level, leaks, smoke, loss of performance,...). Everything checked out and I drove back to the track. I drove 4 hot laps and the gauge functioned fine. All of the sudden, same thing: back to 2.5.

I finished the track day and drove home. For about 70 miles the gauge stayed around 2, sometimes just above 1 while driving 75mph. A couple of miles before I got home, the gauge was functioning normal again.

Do I have a bad sender? Bad connection? Doesn't seem a mechanical issue to me, or is it?

Marlon

Marlon Targa 86

I found this thread dealing with the same issue: LINK

In that case it was a bad sender. Sounds very similar to my issue.

Marlon

Uber 911

Had a similar problem, check your earths down where the battery is in the trunk. There's a big bunch down there..

whalebird

good advice above^^^. It's always a good idea to secure the ground points all over the chassis as a matter of practice. FWIW, make sure the big braided ground strap from the gearbox to the chassis is secure. It is located on the "nose" of the trans and connects to the body just forward of the front trans crossmember on the passenger side. Also, there is a group of grounds located on the drivers side of the intake manifold that should be checked periodically.
It's one thing to have your glove box light act up, but the oil pressure gauge stabs at your emotions when it acts funny(or not funny).
I'm going to shoot from the hip and call it a sender/gauge issue.
Good luck and let us know your findings.

rusnak

At some point, the negative ground cable on the battery should/ will be replaced. I found mine to be too short and too frayed for me. I installed a much longer, heavier one with my last new battery.

whalebird

Rusnak, I was looking for a part number for Marlon and noticed two different pressures(80/150) listed on Pelican. This, I presume, is dependent on which gauge is being used, no? I also told him(PM) that it was a simple in and out, but now I'm second guessing myself..."It might be hard to get a wrench in there, it seems like somethings in the way" I keep thinking. I really need a 911 I can run out and look at before I start giving advice LOL. He wants to try and do this himself and I don't want to mislead him. Any thoughts my friend?

rusnak

Yes. It can be done, but you need to have the right tools. Marlon, some guys use a crows foot wrench, and other guys have gotten away with just a long socket extension and some sort of stubby wrench.

Maybe Ed Hughes can weigh in on this, but I would think the amount of time is dependent on the tools and experience combo.

There was a guy named RNLN (Ron) who had an epic tough battle, and some seem to do just fine. You might need to remove the ac bracket, but that just depends on the tool selection you have.

I just happen to have both the camera and my 911 here, so I'll pop back in w a pic.

whalebird

Here we go...I try to give advice and end up asking rusnak in the same thread. I need to quit before iceman extenguishes my torch and banishes me from air-cooled island - to the 944 ghetto...and I'm out of tikki dolls.
rusnak you are 110% sterling across the board. I go home from a day at work in a good mood because of threads like this. Thanks.
Marlon, we will get you going. There may be an ohm test for the sender; I'll keep digging.

rusnak

LOL! No no no....wb you have strong medicine. Porsche gods protect you.

I'm having a dickens of a time w autofocus.....but guess what. I just found manual focus. Back in a bit.

And 10.0 megapixels is amazing, or my eyes are getting middle aged. I need a new ac belt it would appear.

Marlon Targa 86

Wow, thx guys! Ok, so I did locate the sender unit. Funny thing is, at the track after I noticed the sender was acting up, I opened the deck lid and looked at the very unit. Something in me told me that had to be it. The Porsche Lords were speaking to me.

Anyway, I need to go out and get a crows foot. 24mm right? And an extension.

How do I pop off the wire? Just pull?

Marlon

whalebird

A search on pelican gave me the late Warren Hall's post that there is no "easy" ohm test.

whalebird

a gentle tug should unclip the wire.

Marlon Targa 86

I'm thinking of ordering these:

OIL PRESSURE UNIT


OIL PRESSURE UNIT SEAL

What do you think?

Marlon

rusnak

Man...I was going to post an exploded parts diagram, but this shot shows it pretty dang good.

Somone later will find this thread and go "hmmm....I need a crowsfoot wrench for that".

You might Vise-Grip the old one off once you have the new one in hand, but don't ever admit to that (j/k).

whalebird

That looks correct Marlon-single wire. I feel certain you can get the old one off rendering it useless(channel locks), but you want the new one in your hand (and the crows foot to install it). This is just a referance and not advice...try not to damage anything.