Zero Oil Pressure - any ideas??

snowberrymini · 05-21-2007, 01:11 PM

I live in Belfast, Northern Ireland and I've just imported a 911 from sunny California.

It's a 1970 911 E Targa and it arrived on Saturday morning. The car has been sitting for 3 months during the shipping process and so when it arrived the battery was dead. I give it a good charge for a number of hours and when I started the car I realized the oil pressure guage did not move at all and was registering zero.

I switched the car off straight away as I was afraid to do any damage. I have tried the car again a few times with the same result. Apparently the car was fine before it left CA and the engine sounded fine in the short time it was running. This is my first Porsche and so I have no idea of how serious the problem may be - does anyone have any ideas or suggestions?

Thanks

Paul

foamy911 · foamy911's Garage

1st of all make sure it really has or does not have oil pressure, a mechanical gauge to test would be the best way. Once you have determined if you truly have oil pressure, you can move on from there.

FenderGuy · 05-21-2007, 01:19 PM

Might be the oil pressure sender needs to be replaced. My druck was stuck at 5, changed it out and now it works !!!

boxster03 · 05-21-2007, 02:36 PM

no oil

LakeCleElum · 05-21-2007, 02:39 PM

Quick way to check: Loosen the large bolt on the banjo line that feeds he rockers (one located to the rear of each intake valve cover. Start the engine, if oil come pouring out (I bet it does), you have oil pressure.....Tighten the bolt quickly and troubleshoot from there as to why you have no reading....

2.7RACER · 05-21-2007, 04:05 PM

Let's try some old fashioned trouble shooting.
First we know if the wire to the oil pressure sending unit is disconnected the oil pressure gauge wil read max high.
We also know if that same wire is grounded the oil pressure gauge will read zero, maximum low.
So disconnect the wire to the sender and see what happens.
Now with an ohm meter, read the terminal of the sender to ground.
With the engine running the resistance should vary. Probably somewhere less than 10K ohms.
If the sender reads ground continously, bad sender.
If the sender reads ok and the meter goes up and down, Bad wire.

fanof911 · fanof911's Garage

Hi

Sender problem.
Check it as exposed by tracer.
I doubt there is no oil nor oil pressure in your engine. It is not 3 months of travel that would have damaged the oil pump.

Fanof

emac · emac's Garage

Hey guys

Dont want to be a wise a$$ but don't you think the first thing he should do is pull the dip stick out and see if there is any oil?? I would say that is the most easiest. Not saying it could be so low as to not show on the stick. Just my 2c.

fanof911 · fanof911's Garage

Good point emac

Fanof

snowberrymini · 05-22-2007, 04:09 AM

Hi

Thanks for the responses guys and a quick update - the oil level guage is reading half full (6 I think), and I checked the dipstick and it is showing about the same. The oil pressure guage is still not registering though.

I'm beginning to wish I had just stuck with the classis Mini coopers - everything is so much simpler (and cheaper)!!

fanof911 · fanof911's Garage

Then it is the sender.

Not quite difficult to assess and to change and not much expensive, in France at least.
I have a tech article on it but in french, if you're able to read french I can send it. Let me know by PM.

Fanof

Rot 911 · 05-22-2007, 05:02 AM

Quote:

Originally posted by fanof911
Then it is the sender.
Not quite difficult to assess and to change and not much expensive, in France at least.
I have a tech article on it but in french, if you're able to read french I can send it. Let me know by PM.
Fanof

Probably, but I'd sure as hell be checking to see if the oil pump is working first!

jabb · 05-22-2007, 05:36 AM

Quote:

Originally posted by Kurt V
Probably, but I'd sure as hell be checking to see if the oil pump is working first!

I agree lets not Assume its the sender. Confirm it but doing the checks mentioned earlier in this post.

foamy911 · foamy911's Garage

Yes, while it is almost surely the sender/wiring, PLEASE AT THE VERY LEAST CRACK THE BANGO FITTING ON EITHER OIL LINE AND HAVE A BUDDY CRANK IT WITH THE COIL WIRE DISCONNECTED.
Once we are sure we have oil pressure do the sender tests 2.7Racer outlined.

mrfluks · 07-02-2007, 01:03 PM

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Let's try some old fashioned trouble shooting. 

First we know if the wire to the oil pressure sending unit is disconnected the oil pressure gauge wil read max high. 

We also know if that same wire is grounded the oil pressure gauge will read zero, maximum low. 

So disconnect the wire to the sender and see what happens. 

Now with an ohm meter, read the terminal of the sender to ground. 

With the engine running the resistance should vary. Probably somewhere less than 10K ohms. 

If the sender reads ground continously, bad sender. 

If the sender reads ok and the meter goes up and down, Bad wire.

I'm having a problem with my oil pressure/temp guage not indicating. The temp guage is pegged to the top and pressure is peggen to the bottom. I did the above checks on the senders and they work just fine. I'm not the greatest with a volt meter but if someone can explain it I can do any checks. Anyone able to help or know what other problems I may have?