RichardL

The oil pressure readings on my '89 Carerra are becoming increasingly erratic! Sometimes everything seems to be OK but most of the time the needle stops suddenly at 2 bars. Then at the next set of lights it returns to 1 and then works OK for a while more!
Is this more likely to be a guage or a sender unit problem?
If it's the sender unit how do I change it? It looks very awkward to get at!

Brian Olsen

[quote]Originally posted by RichardL:
<strong>The oil pressure readings on my '89 Carerra are becoming increasingly erratic! Sometimes everything seems to be OK but most of the time the needle stops suddenly at 2 bars. Then at the next set of lights it returns to 1 and then works OK for a while more!
Is this more likely to be a guage or a sender unit problem?
If it's the sender unit how do I change it? It looks very awkward to get at!</strong><hr></blockquote>

Brian Olsen

[quote]Originally posted by RichardL:
<strong>The oil pressure readings on my '89 Carerra are becoming increasingly erratic! Sometimes everything seems to be OK but most of the time the needle stops suddenly at 2 bars. Then at the next set of lights it returns to 1 and then works OK for a while more!
Is this more likely to be a guage or a sender unit problem?
If it's the sender unit how do I change it? It looks very awkward to get at!</strong><hr></blockquote>


Richard,
I'd vote for the oil pressure sender. Mine has failed twice. Removal & replacement is very easy, if you use a crow's foot of the correct size, and a ratchet extension. I believe I used 15/16", which is about 24 mm. I'm not 100% sure of the size, though, since I'm at the office now. Get a replacement, and see what size wrench fits, and get a crow's foot of that size. Removal and replacement will be almost impossible otherwise. The sender costs about 50 USD.

Regards. Brian

an6drew

Brian,
did you need to remove the A/C compressor & mount or anything else to do this? I've just received a replacement sender for my '82 SC. Havent got the crowsfoot yet, but it looks like it'll be extremeny tight in there?

thanks,
Andrew

RichardL

At the risk of sounding stupid ...... I am Irish! What's a "crows foot"?

Chris Martin

I replaced mine with a socket, no bid deal. This was about a year ago, but I think I did remove the AC bracket.

nylart

Before you spend any $ on the sender or the guage, check the wire from the sender to the gage. If iy is not making a solid connection from one end to the other, you can get erratic readings. Also check the wire connector at the sender. The wire could be broken inside and you can't tell just by looking at it. Hold the connector in one hand and wiggle the wire to see if it is loose. Replacing the connector saved me about $50 on my 84.

Art

HarryD

[quote]Originally posted by RichardL:
<strong>At the risk of sounding stupid ...... I am Irish! What's a "crows foot"?</strong><hr></blockquote>

Richard,

No dumb questions!!

A crows foot is an open end wrench that allows you to attach it to a rachet handle.

They look like this:



BTW. I was in Dublin years ago and I still think the Irish are some of the finest folks on earth.

Cheers!

RichardL

Thanks Harry!
Funny .... but I've never seen a "crow's foot" before even in fully equipped workshops but they look really useful! With my rather rudimentary engineering knowledge they look like they would try to push a nut rather than turn it ... but obviously not!

Bill Pauling

Richard,

If the oil pressure gauge sender has failed, the needle should go all the way to the top of the gauge (i.e. &gt;5 bar). I would first check the connections at the sender and the gauge. If you do end up replacing the sender, I suggest removing it and its mounting block as a single unit, then separating the sender from the mounting block. It's on there pretty tight and the torque required to separate the sender from the mounting block could strip the connection to the case.

First, disconnect the a/c compressor and lay it aside. Then disconnect the right side flexible oil line. Then you can remove the banjo bolt that holds the sender mounting block to the case and remove the sender and the block as a single unit. Now, put the mounting block in a vice and use a 24mm wrench to separate the two.

85targa911man

Richard--

I agree with all the foregoing, but I have to add that I know lots of 911 owners but I don't know anyone with a pre-90 911 that has a pressure gauge that works perfectly. It seems that even the most accurate ones only provide approximate readings and at best act as a warning light in analog dial configuration to alert you when things suddenly change. And as your experience indicates, often when you see a sudden change it is the sender or connection that is the problem as opposed to the pressure.

RichardL

Thanks for all the advice guys!
I've ordered a sender unit from "Pelican Parts" but I'm going to check out the connections at both ends first. It looks alright at the sender end but I'll check it with a "meter" over the holiday. I had a quick look at removing the guage from the dash ("101 Projects" says it should be easy!) but it was very tight - I was worried that I might scratch/damage the vinyl - any advice?

steve911

RichardL--
removing the gauges is relatively easy. Using a thin, flat blade screwdriver, GENTLY wedge it under the rubber surround and GENTLY pry up (use the adjacent gauge for leverage).

I've found that I only need to wedge it up a little before I can use finger force to pull it straight out.

Also, if you remove the tach first using the technique above, you can reach in through the dash and push the oil pressure gauge out.

RichardL

Well I changed the oil sender unit and the problem appears to be solved! I couldn't find a 24mm "crows foot" locally (very rarely used apparently on this side of the pond!)so I had a friend heat and bend an old 24mm spanner and it fitted perfectly. The job took 5 minutes.
Very small achievment I know but I certainly wouldn't even have thought of doing it on the new Audis and BMWs I've been driving for the last 15 years - very satisfying!!!
Thanks for all the advice!