1973 Porsche 914 2.0L. I’m removing my Oil Temp Gauge and installing a Oil Pressure Gauge. I installed a 100 psi VDO Oil Pressure Gauge. Do to the size of the new Sender Unit that fits a 100 psi VDO Gauge you cannot just insert it in the same location in the Taco Plate! I was able to drill a 7/16 hole in the same plate and install the new sender unit. I left the original sender unit where it was at and just removed the plug and placed it on the new 100 psi Oil Pressure Sending Unit. On the other end I just plugged the original harness back in the same 3 prong plug in on the back off the new VDO Oil pressure gauge. Sending unit wire to G and the + to fuse box etc. No reading on gauge! What’s wrong. The new sending unit is extended about 1/2” inside. Any suggestions. Thanks

no pressure in oil sump = GOOD THING

Could there be a problem with not getting enough oil to the Pressure Sender in that location? I’ve ran all continuity test on wiring, all seams good. New Sender and VDO gauge.

The place where you are hooking it up is meant to read oil temperature. In order to read oil pressure you have to tap into the oil pressure sender unit that is next to the distributor. In order to do so, you will need to get a pressure hose installed into the hole and an extension because the sender doesnt fit in the original hole. Search pressure sender extension on here so you can see.

Oil pressure...from the pump...there's no oil pressure in the sump taco plate location.
It has to be installed in the oil circuit, in an oil galley.

Most use the oil idiot light sensor location, but to do this you need an extension hose. You can get one from VDO, some use a grease gun whip but it's not really the correct thread.
Either way you have to make a metal bracket to mount the sender somewhere, the body of the sender must be grounded to the engine to work.
I also would use a T so you can keep the stock idiot light switch.

Thanks for all the valuable information, I was obviously misdirected earlier. I will correct that error. Thank you.

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I had a piece like this machined to elevate my pressure sender from the stock idiot light location. The sender has two outputs, one for the gauge and one for the idiot light.

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Mounted it looks like this.

That doesn't look like it would clear a stock distributor.

You need an extension, I have several of them here from Draft 42 design, I will toss one in the box with your 911 engine tin.

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Not a good idea. Now you have the weight of the sender and extension pipe all working on the little pipe threads in the case. The pipe acts as a lever arm, even though a short one, and the vibration can eventually damage the threads or the hole in the case.

The flexible hose is a better idea, though you do have to make sure to ground the outside of the sender.

--DD

I agree, That elevated sender held by that pipe thread is a fatigue machine waiting for enough cycles before the fitting fractures right at the thread where in emerges from the case. Remember, lots of vibration going on in that location, so positive/ negative stress cycles occurring
then major oil leak !!

That is dangerous. It will break and send a oil spout out of the top possible causing a fie when it hits the exhaust pipes/ Use a rear brake line from a 928 Porsche. 92835508002, $20 at 'Reilly.

https://www.oreillyauto.com/shop/b/brake-sy...982/porsche/928

My offer taken off the table BTW

I used a metal braided paint ball gun hose. They have several lengths. Some folks use grease gun lines. I then mounted the sender on the fan housing with a metal strap to ground it all. Truthfully, I hate the idiot light feature on the VDO sender. The vdo sender lights my green dash light at just under 10 psi. Hot summer days at stop lights and the damn light comes on.

I have a gauge in the engine bay too. It tells me that the OP is OK even when VDO lights the lite.

The Draft 42 rig allows you to use the stock OP sender and the vdo sender, plus a direct gauge. You get 1 in, and 3 out. I have the rig, but have yet to install it.

Thanks for all the suggestions. I think I will go with the extended hose which I found one locally. Thank you

'74, 2.0L

Could someone please assist me in the selection of a sending unit? I see the VDO brand (above in the pictures)but could not read the numbers.

I am mating it to a VDO replica gage: https://www.ebay.com/itm/123371842913

Thank you,

CTC911CTC

BUMP

I Vehemently Disagree.

More than 20 years ago, I had a hose like you describe on Betty's car. It broke and sprayed oil all over the engine compartment. We almost lost the engine due to a loss in oil pressure. I will never put one on an engine I build. EVER.

Since then, I have run a T fitting to hook up the oil pressure sender, and the idiot light switch. It is mounted as low as possible, putting the pressure sender on its side, laying on the tin. This fixes the worry about the weight of the switch causing the fitting to crack from vibration. The idiot light switch is screwed n the top.

In over 20 years and over 300K, I have never had one break.

And Porsche used an extension on the 964 motor for the oil pressure sender/switch.

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Just because everyone does it that way, doesn't mean it is the right way to do it.

If it is a proper metal the stand off are the best way to go. Most people will go and pick some brass fittings and they will fail 100% of the time.

Proper quality hose will work.

Proper quality stand off will work also. The Porsche PN Clay shows has worked over 1,000,000,000 of accumulated miles. It will work, if the threads match up. Could also have one machined up with the proper thread, I would do it in steel just to make sure it was positive and good stable platform. Aluminum could be a good fit if the proper alloy is picked. Not an AL expert in alloy mixes, so I don't want to recommend the proper allow mix.

I will say like anything you need to check this stuff, it is never a just install and forget it. Anything that takes pressure over repeated cycles will have an element of failure.

Any suggestions will be welcome, thanks in advance!

https://www2.cip1.com/ProductDetails.asp?Pr...VDO%2D360%2D001

I think that's the one - if you're looking at the gauge, i'd send a note to AutoAtlanta/George since that's their gauge and one of their Ebay outlets.

btw - that is a single pole - no idiot light connection. My plan is to use that sender to that gauge and the OEM sender to the idiot light via the Draft 42 kit.

EDIT: yes - i'm going with that answer. 0-80 range as is the gauge.
here's the version with the dual pole which will also trigger your idiot light but it will be at a higher pressure and may cause you to freak out which is why i'm planning on using the OEM sender.

https://www.summitracing.com/parts/vdo-3600...4RoCyhIQAvD_BwE