Oil Pressure Gauge Doesn't Work Properly (was Oilpressure-sensor for the 1.2N engine) - Page 2

namba209 · 03-14-2006

If you have the two wire oil pressure transmitter, swap the wires at the transmitter. One side is just for the light, the other is for the guage. Sounds like maybe they could be hooked up wrong. HTH.

CDN OpelNut · 07-18-2008

Originally Posted by tekenaar

Standard "VDO gauge" sender range is 10-180 ohms and the idiot light is merely an on/off switch that is closed with no pressure and opens at ~7psi.

If you should connect the GT's OP sender wires up backwards, here's what happens:

When you turn the ignition key on, the OP gauge is at ~0 (switch closed) and the idiot light is brightest (10 ohms). When you turn the engine over to start it and the oil pressure reaches ~7psi, the gauge needle pegs (switch opens, infinite ohms) and the idiot light progressively dims as pressure builds (10-180 ohms).

That said, if your OP gauge was behaving normally and then your gauge suddenly pegs the next time you turn on your ignition key, the first thing to look for is a broken "gauge" connection at the OP sender, else the internal connection to the OP sender rheostat is open. Open OP sender rheostat connection is not fixable . . . time to replace OP sender, I'm afraid.

OK - So what about these symptoms?

Both lights on the on the gauge come on when the keys is first in the "run" position (as they should)
When the engine is running, the needle immediately pegs to above 5 bars and stays there regardless of RPM, but,
the idiot light is on steady and bright regardless of RPM

Engine is fresh rebuild and the sender is a brand new VDO unit ordered from egauges.com

How can the pressure be high and the warning light on at the same time?

jlthunder · 07-18-2008

It could be a bad sender. If the wires were reversed, the light would change intensity once the engine was started. The gauge is fine otherwise it would peg before you started the engine.

With the engine running. Remove one wire to see if the light goes out. Then remove the other wire and see if the gauge goes to zero. If this happens, then the sender is most likely bad.

Why was a new sender installed? Did the old one do the same thing?

CDN OpelNut · 07-18-2008

Originally Posted by jlthunder

Why was a new sender installed? Did the old one do the same thing?

Ok, I'll try that. The old sender worked fine, but was original, the rubber boot was toast, so I replaced it.

tekenaar · 07-19-2008

Originally Posted by CDN OpelNut

Ok, I'll try that. The old sender worked fine, but was original, the rubber boot was toast, so I replaced it.

. . . original OP sender boot served as a heat shield and has absolutely nothing to do with its functioning!

. . . DFTTAB

CDN OpelNut · 07-21-2008

Originally Posted by tekenaar

. . . original OP sender boot served as a heat shield and has absolutely nothing to do with its functioning! . . . DFTTAB

So who builds a shiny new motor and dresses up the engine compartment and then puts back on the oily OPSU with the cracked, ratty cover?

Not me

tekenaar · 07-21-2008

Originally Posted by CDN OpelNut

So who builds a shiny new motor and dresses up the engine compartment and then puts back on the oily OPSU with the cracked, ratty cover?

Not me

. . . then just remove that little rubber bootee and buff up the OP sender case . . . just like new!! . . . and costs nothing but elbow grease!

tomking · 07-21-2008

Originally Posted by tekenaar

. . . then just remove that little rubber bootee and buff up the OP sender case . . . just like new!! . . . and costs nothing but elbow grease!

That is what I did with mine. I have yet to see one that doesnt have its rubber cover cracked.

jlthunder · 07-21-2008

Originally Posted by tomking

That is what I did with mine. I have yet to see one that doesnt have its rubber cover cracked.

Is that why we have so many little Opels running around

Any word on the repair?

tomking · 07-21-2008

Originally Posted by jlthunder

Is that why we have so many little Opels running around

Any word on the repair?

LOL! JT what are you thinking?

jlthunder · 07-21-2008

I just couldn't resist

We learned about things like that in health class!!

tomking · 07-21-2008

Originally Posted by jlthunder

I just couldn't resist We learned about things like that in health class!!

But why would anyone think they could repair a cracked rubber? Why chance it?

Cyeogeo · 07-21-2008

My 71 GT does the same thing. The idiot light is on all the time and the gauge is pegged high. I removed the oil pressure sender and checked the resistance. G was 8.5 Ohms and the WK contact was closed.
Checking the wires I found mine seem be routed (or pinched?) between the bell-housing and engine. Where are the wires supposed to be routed?

tomking · 07-22-2008

The wires are trained around the bell housing and back of the engine and into the firewall. As far as I know there arent any clips that hold them around the back of the engine either.

BQS4 · 07-22-2008

Originally Posted by Cyeogeo

Checking the wires I found mine seem be routed (or pinched?) between the bell-housing and engine. Where are the wires supposed to be routed?

This is a common problem, happens when a clutch is replaced. The wires for the oil pressure sender do go behind the head, but, unless you have that thought in your head and remove them out of the way, they get caught in between the bellhousing and the block. Simple fix is to trim off the wire(s) and splice in new. Then make a way to hold the wire up out of the way, the next time the clutch is replaced, it won't get caught.

CDN OpelNut · 09-01-2008

Originally Posted by Cyeogeo

My 71 GT does the same thing. The idiot light is on all the time and the gauge is pegged high.

As per my previous post, mine is the same. I had a chance to look a this today. Got a nice exhaust burn for my efforts

.

When I pulled the WK wire from the sender, the light was still on!

I connected WK wire back up, and pulled the G wire off, the light went out but the gauge still pegged.

I was pretty careful labeling the wires when I ran them, but I will reverse them and see what happens.

Any other ideas?

tekenaar · 09-02-2008

Originally Posted by CDN OpelNut

As per my previous post, mine is the same. I had a chance to look a this today. Got a nice exhaust burn for my efforts .

When I pulled the WK wire from the sender, the light was still on!

I connected WK wire back up, and pulled the G wire off, the light went out but the gauge still pegged.

I was pretty careful labeling the wires when I ran them, but I will reverse them and see what happens.

Any other ideas?

. . . can't read the letters on my OP sender, but, with original sender wiring, slip-on spade connection is idiot light, screw-on ring terminal is gauge, OK!

. . . uh, looking at your post again, it's obvious . . . G is gauge!!!

. . . and your wires are bass-ackwards!

. . . and, upon further review, WK bedeutet/means Wackelkontakt - momentary/rocker switch . . . i.e. idiot light ON/OFF!

CDN OpelNut · 09-02-2008

Originally Posted by tekenaar

. . . can't read the letters on OP sender, but slip-on spade connection is idiot light, screw-on ring terminal is gauge, OK!

Yep. I marked the OPS with a Sharpie before I put it in. I'll reverse them and see.

03-14-2006	#26 (permalink)
namba209 5,000 Post Club Join Date: Aug 2002 Location: Imperial Beach, CA South of San Diego Posts: 5,966 Classified Rating: 0% (0) Provided Answers: 4	If you have the two wire oil pressure transmitter, swap the wires at the transmitter. One side is just for the light, the other is for the guage. Sounds like maybe they could be hooked up wrong. HTH. Last edited by tekenaar; 07-21-2008 at 11:00 AM.. Reason: lite - diet? gage - vickie or allen?

07-18-2008	#28 (permalink)
jlthunder 1000 Post Club Join Date: May 2003 Location: Salfordville, PA Posts: 1,824 Classified Rating: 0% (0)	It could be a bad sender. If the wires were reversed, the light would change intensity once the engine was started. The gauge is fine otherwise it would peg before you started the engine. With the engine running. Remove one wire to see if the light goes out. Then remove the other wire and see if the gauge goes to zero. If this happens, then the sender is most likely bad. Why was a new sender installed? Did the old one do the same thing?

07-21-2008	#36 (permalink)
jlthunder 1000 Post Club Join Date: May 2003 Location: Salfordville, PA Posts: 1,824 Classified Rating: 0% (0)	I just couldn't resist We learned about things like that in health class!!

07-22-2008	#39 (permalink)
tomking Member Join Date: Aug 2002 Location: SW Missouri Posts: 1,042 Classified Rating: 0% (0)	The wires are trained around the bell housing and back of the engine and into the firewall. As far as I know there arent any clips that hold them around the back of the engine either.