[Solved] 3.8 low oil pressure

[paydase]

As it is, I can always easily remove the mechanical gauge.
I like to keep the original electric one in place.
Will see in the future

[mtnjag]

Caerbont Automotive will set you up with identical gauge in mechanical so you have the orig gauge in the dash. Others will convert you Egauge to mechanical with your face i believe.

[Gfhug]

Serge, seeing how the gauge mount has cut your jeans be careful as next time it’ll cut your kneecap off!
Actually a serious point as it will be very easy to cut yourself on it when wearing shorts.

Geoff

[paydase]

Haha, good point on worn jeans!
I took care to prior check the positioning of the gauge before installing it in order not to be in the way of my knees and also to see it correctly through the steering wheel when driving.

Wrt purchasing of a new gauge from Caerbont or other suppliers, I decided instead to buy a used one because I read mixed reviews about newly fabricated mechanical gauges (not only electrical ones).
This one was a very good find on ebay as it is a NOS gauge for works Mini Cooper.
I bought the piping and connections from Merlin Motorsport.

[mtnjag]

Never had a problem with mine. 0-100 mechanical, 25 years old. Looks orig, in orig location, no knee bumper.

[paydase]

Here is the path I chose after looking at various options.

Firstly, I preferred connecting the gauge directly on the oil rail close to the filter housing, instead of installing a tee inbetween the electrical sender and the filter housing.
Looked to me simpler in terms of fittings:

IMG_20221214_153007.jpg (250.76 KiB) Viewed 7391 times

Secondly I routed the braided hose through an existing hole in the front shield (just had to cut open an existing rubber plug):

IMG_20221214_153520.jpg (217.9 KiB) Viewed 7391 times

[paydase]

Then arrived to existing large opening in the passenger footwell and routed it, hidden behing the moquette, until the open space between the dash and radio console:

IMG_20221123_193053.jpg (238.08 KiB) Viewed 7391 times

Finally had the hose coming out on the driver side and connected to the back of the gauge which was attached using existing bolt on the side of the radio speaker.
No kinks on the hose that had enough space, and no risks of electrical shorts as the Merlin braided hose is externally protected with some sort of plastic:

IMG_20221218_121929.jpg (255.67 KiB) Viewed 7391 times

[mtnjag]

Very similar to what I did but brought it in an existing hole to behind the dash and into the gauge.

[paydase]

Yes Layne, I had seen pictures and description of your installation (was useful), but I figured out that it would not be straightforward to route the hose through that hole with the mechanicals of the wipers.
Also I wanted to keep the original gauge in place, at least for the time being.
Btw, a 2 metres long hose was just what was necessary to route it until the place chosen for the gauge.
1.5 metre would be enough for a gauge in the dashboard panel.

[mtnjag]

The nice thing about working on your own car is you can set thing up the way you want. Can be very satisfying.
Forgot there were pics of my install, still do!
Good luck, nothing like a mechanical gauge read out.

[Redman]

Guys: I'd like to install a mechanical sender and guage on my early S3 (1971). I'd also like to bring everything to a more accessible spot (the existing oil pressure switch and oil warning light switch senders are almost impossible to get to at the rear of the engine. When you say you just access an oil rail elsewhere, is there a specific drilling to take the sender? Adapters needed? Thanks.

[mgcjag]

Your post will best be answerd in the S3 section rather than under a 3.8 low oil pressure heading....if i remember correctly the info your after is already in the S3 section if you search....or put up a new post specific to fitting a mechanical guage.....Steve....edit....i see you already have a post on this in the S3 section

[Jack the lad]

I have read this post for the first time today and find it very interesting and informative, however it would seem that the most likely culprit has not been investigated. I refer to the voltage regulator for the dash instruments, the little metal box containing a bi-metal strip that reduces the variable line voltage from anywhere between 11 volts and 14 plus down to a consistent 9 Volts. These are not good at the best of times and with moisture showing inside the gauges the voltage regulator will also be wet. I know that the fuel gauge and the water temp gauge get their supply of 9 volts through this regulator and the oil gauge gets it full 12 to 14 volts directly from the fuse board, or it did when the car was made. I have found several cars with the oil gauge connected to the 9 volt line and as a consequence it reads low. Done I guess by an enthusiastic owner or restorer. Easy to check just read the supply voltage at the rear of the oil gauge with the ignition in the run position, should be battery voltage. Also worth a check on the output of 9 volts at the small regulator at the same time, if this is faulty you will not get accurate fuel and temp readings.

[tim wood]

I thought it was 10 volts from the regulator ?

I followed a modification published on here and replaced the old bi metal inards with a simple electrical component. Works well


Tim