oldskewel

The oil pressure gauge on my '85 is reading too high, and I'm looking for advice on likely problems before I start troubleshooting (forgive my laziness, please).

I've had the car for 17 years, so am used to the pressure gauge bouncing while idling, etc.

Now, it seems to read at least 3 bar too high. At idle, the gauge is near-pegged at 5 bar+. When driving, it is pegged at 5 bar+. When power is on, but the engine is stopped, it reads 2-3 bar.

The pressure warning light acts normally.

My thoughts (tell me if I'm wrong, etc.):
- the actual oil pressure in the engine is most likely just fine, as always
- either the sender or the gauge is bad. Any easy tests recommended?

Mount311

Had the same problem with mine last year. First start by checking your connections on the sender you might need to clean them. If that doesn't work I would say its the sender. I read many threads on this and it was almost always the sender and when not it was the connections. I really didn't see many on the gauge going bad. The sender is an easy fix ( took me about 45 min) and not very expensive.

theiceman

45 mins ? did you spend 30 of it having a beer ?

Mount311

Haha! I wish... That was my first time replacing something like that so I took it real slow.

Mister Moo

Very easy to change a pressure sender if you don't have airconditioning; very pita if you do. I just replaced one on my air conditioned car and it took a couple of hours.

oldskewel

Great information - just what I was looking for.

My AC is out, so it should only take me 1:15 - 30 for the beer, 30 to clear out the kids toys so I can get to my tools, and 15 to fix it. I'll post a followup when I get around to it.

Mister Moo

Piece of cake w/o the AC cmpressor bracket in-situ. The bracket is fastened afoul of the sender. You need to do a mess of work to get to the lowest part of that bracket (an hour) so you can access and replace the sender (5-min); then another 45-60 minutes to put it all back.

Next time a sender fails I'll maybe just count on the idiot light.

theiceman

i cant remember if that thing pukes out some oil when you change it.. do it with the engine dead cold so if it does you can contain the spillage as cold oil pukes slower .. Maybe it was the temp sender i remember puking a bit ..

Mister Moo

A rag is good; sorta spits up rather than pukes.

theiceman

btw if you wanna do a quick check remove the wire from the sender with the ignition on. you should get total defection one way, then ground it to the engine and it should deflect totally the other way. if this happens the guage is working and its the sender.

oldskewel

Yes, this is a very good and easy test. It easily confirmed that I have a bad sender. Next step is to buy one.

I scoped out the R+R and even though I've got most of the AC removed, the lower bracket is still there. I will need to remove that - got it all except what appears to be two bolts right up next to the muffler, accessible from under the car. Does that sound right? It looks like I'll need to remove or at least loosen the muffler to get those screws. If there is an easier way, please let me know. My rule of thumb is to never remove anything unless I have to. The good news is that I will keep the bracket out after installing the new sender.

theiceman

And crows foot?

Just looked at a buddies car with ac and looks like a crows foot would help

Peter Zimmermann

OP; you can get to the bolts for the lower A/C platform support without exhaust work. You must raise the rear of the car a couple of feet, which will make the entire job easier, secure the car on jack stands, and crawl under the back. You'll see the lower bolt. The upper bolt is in the engine compartment, and is a little tricky to loosen.

Once the bracket is out, as ice mentioned, a crowfoot socket will make sender R&I easier. However...yes, there's always a however...you might discover that the sender is so tight that your job just got bigger! If you can't get the sender loose, examine the inboard end of the right cam oil line. You will have to loosen that (put a folded paper towel under it to catch the few drops of oil that will leak), as well as the upper auxiliary oil line fitting (on the very thin, solid line that feeds oil to the tensioner). Once the oil lines are loose (DON'T allow the end of the cam oil line to turn where it meets the rubber section!), remove the fastener that the cam oil line attached to. That fastener is a "bolt" that passes through the "block" the sender attaches to, screws into the crankcase, and it has seal washers that should be replaced. Once the bolt is out, the sender and mounting block can be removed, put in a vise, and the sender can be unscrewed.

Clean everything, install the new sender, and put the thing together. Don't overtighten the "bolt," I've seen those actually bend, and then they won't seal properly. Regarding the cam oil line, if the metal end turns at the rubber section, replace the line. If it's not already leaking, it will start to leak shortly!

Good luck! Whatever you do, you don't want this to happen:
http://forums.pelicanparts.com/porsc...l-how-fix.html

oldskewel

I finally got around to this today. I followed Pete's instructions with the following comments:

I didn't really jack it a couple of feet, but did put it on stands, which was helpful since I was down there for a while.

I did not remove any exhaust components, but I did loosen several bolts + the two muffler straps, since I needed just a little more wiggle room than I had.

It probably took 2+ hours to get that AC bracket out. (and it's staying out - the compressor, etc. were removed years ago)

I then spent ~1.5 hours trying and failing to get the sender out.

So I resorted to Peter's instructions on the oil line and had the sender+block out in minutes. No problems with the cam oil line.

Then I spent ~1+ hours with the sender+block in a vise, etc. failing to separate them.

Finally, I dremel tooled the can off the top of the sender, got it down to the real metal, heated it up, and finally it came loose. Amazingly, the threads look just fine and the new sender spun into the old block easily by hand.
So I'll get the 3 seals (1 for the sender, 2 for the block) and put it back together. Everything looks solid so I don't expect any problems.

By far, that was the most difficult easy thing I've ever done on this car. Usually, I am impressed at how easily things come apart, etc. and only have problems like this on my other cars.

And now that the frozen threads were cracked open, I expect I could R+R in minutes.

So thanks ice and Pete for the great instructions - amazing how Pete knew I'd run into that problem and would need some extra dis-assembly of the oil lines. Good thing I did not keep going at it while it was in the car because it never would have worked and I would have broken something.