Home  |  Forums  |  914 Info  |  Blogs
 
914World.com - The fastest growing online 914 community!
 
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG. This site is not affiliated with Porsche in any way.
Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners.
 

Welcome Guest ( Log In | Register )

 
 Reply to this topicStart new topic
> Oil pressure light on, but it's really dim, Replaced the pressure sender, it's still on
RoadGlue
post Jul 26 2006, 08:29 PM
Post #1


Sonoma County Gear Head
****

Group: Admin
Posts: 2,033
Joined: 8-January 03
From: Santa Rosa, CA
Member No.: 108
Region Association: Northern California
The other night I was driving the '74 2.0 home and I noticed that the oil pressure idiot light was on, but very dimly. I pulled over right away, checked oil level, turned the car to "ON" (not start) and noticed that the oil light was on, but was bright like you'd expect it to be.

I debated having the car towed, but I've had what I thought was a similar problem with a bad pressure switch on another 914 and decided to drive it home. The car drove normally and the engine sounded perfect, though the oil light was still dimly staring back at me.

Finally had a chance to swap out the sender tonight and it's acting the same way. Turn ignition switch to "ON" and it's bright. Start the car and it's on, but dim.

It's a very solid dim. No flickering or changes in luminosity depending on engine RPM. There's no engine oil spewing out when the car's on either. (IMG:style_emoticons/default/smile.gif)

I think there's a problem elsewhere. Obviously I need to make sure I have good oil pressure before driving it, and I'm going to borrow a screw in pressure gauge from my machinist friend before doing so.

With that said, what are the odds that I have low oil pressure? 914s that I've had before with low oil pressure had idiot lights that flickered, usually brightly. If it's an electrical problem, where should I start digging?

Thanks!
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
lapuwali
post Jul 26 2006, 08:50 PM
Post #2


Not another one!
****

Group: Benefactors
Posts: 4,526
Joined: 1-March 04
From: San Mateo, CA
Member No.: 1,743
Try dimming your dash lights. Perhaps the gauge light is bleeding into the oil pressure "window".
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
RoadGlue
post Jul 26 2006, 09:07 PM
Post #3


Sonoma County Gear Head
****

Group: Admin
Posts: 2,033
Joined: 8-January 03
From: Santa Rosa, CA
Member No.: 108
Region Association: Northern California
QUOTE(lapuwali @ Jul 26 2006, 07:50 PM) *

Try dimming your dash lights. Perhaps the gauge light is bleeding into the oil pressure "window".


Thanks for the suggestion! I tried dimming the dash lights, but it didn't make a difference.

Let's say I do have low oil pressure... could the light be half as dim as it is when the motor is turned off, but the switch is in the ON position?
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
JoeSharp
post Jul 26 2006, 09:11 PM
Post #4


In Irvine, Ca. May 15-18
****

Group: Members
Posts: 3,947
Joined: 9-July 03
From: DeLand, Florida
Member No.: 898
Region Association: South East States
No, that light is getting power backfed somewhere. The oil light is on or off.
:PERMAGRIN: Joe
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
RoadGlue
post Jul 26 2006, 09:54 PM
Post #5


Sonoma County Gear Head
****

Group: Admin
Posts: 2,033
Joined: 8-January 03
From: Santa Rosa, CA
Member No.: 108
Region Association: Northern California
QUOTE(Joe Sharp @ Jul 26 2006, 08:11 PM) *

No, that light is getting power backfed somewhere. The oil light is on or off.
:PERMAGRIN: Joe


That's reassuring, thank you!

Perhaps I can run a jumper from the sender to the light as a test... or does it go through a resistor? I'd better look at a wiring diagram before I get silly.
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Dave_Darling
post Jul 26 2006, 10:39 PM
Post #6


914 Idiot
***************

Group: Members
Posts: 15,155
Joined: 9-January 03
From: Silicon Valley / Kailua-Kona
Member No.: 121
Region Association: Northern California
The sender is just a switch. It either grounds the wire going to it, or leaves it disconnected. Somehow there is something else hooked up there, but with a bunch of resistance...

I know the light behaves oddly when you hook up a sender for a gauge to it... Is your sender the stock one or the big fat cannister one?

--DD
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
RoadGlue
post Jul 26 2006, 10:50 PM
Post #7


Sonoma County Gear Head
****

Group: Admin
Posts: 2,033
Joined: 8-January 03
From: Santa Rosa, CA
Member No.: 108
Region Association: Northern California
QUOTE(Dave_Darling @ Jul 26 2006, 09:39 PM) *

The sender is just a switch. It either grounds the wire going to it, or leaves it disconnected. Somehow there is something else hooked up there, but with a bunch of resistance...

I know the light behaves oddly when you hook up a sender for a gauge to it... Is your sender the stock one or the big fat cannister one?

--DD


Hi Dave!

It's the stock type. The rellocation hose for the big pressure sender cannister is on its way from aircooled.net now, so those *fancy* bits are still sitting on the shelf.

OK, I think I feel comfortable driving the car now. I'll try to track down the source of the bleed-through this weekend.

Cheers!
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
RoadGlue
post Jul 27 2006, 12:21 PM
Post #8


Sonoma County Gear Head
****

Group: Admin
Posts: 2,033
Joined: 8-January 03
From: Santa Rosa, CA
Member No.: 108
Region Association: Northern California
So there is certainly some bleed-through happening here. I disconnected the wire at the pressure sensor and the dash light is still dimly on. Whew. This car has a few spooky electrical issues that I need to sort out.

Thanks everyone!
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
Brad Roberts
post Jul 27 2006, 12:25 PM
Post #9


914 Freak!
***************

Group: Members
Posts: 19,148
Joined: 23-December 02
Member No.: 8
Region Association: None
Check all the grounds on the back of the gauges.

Make sure and pull all the other "bulbs" out of the back and clean them also.

B
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
RoadGlue
post Jul 27 2006, 12:32 PM
Post #10


Sonoma County Gear Head
****

Group: Admin
Posts: 2,033
Joined: 8-January 03
From: Santa Rosa, CA
Member No.: 108
Region Association: Northern California
QUOTE(Brad Roberts @ Jul 27 2006, 11:25 AM) *

Check all the grounds on the back of the gauges.

Make sure and pull all the other "bulbs" out of the back and clean them also.

B


Do you *really* think there would be grounding issues on this car? It *only* sat for four or so years, outside... neglected... unloved. (IMG:style_emoticons/default/wub.gif)

OK, I'll check 'em. I seem to recall that the turn-signal indicator light comes on dim from time to time too. I'll pull the gauges and fuse block and clean all that up.

Cheers,
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
« Next Oldest · 914World Garage · Next Newest »
 

Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:

 

Display Mode: Standard · Switch to: Linear+ · Switch to: Outline

Track this topic · Email this topic · Print this topic · Subscribe to this forum

- Lo-Fi Version Time is now: 30th April 2025 - 07:02 AM
Invision Power Board v9.1.4 © 2025  IPS, Inc.
All rights reserved 914World.com © since 2002
914World.com is the fastest growing online 914 community!
We have it all, classifieds, events, forums, vendors, parts, autocross, racing, technical articles, events calendar, newsletter, restoration, gallery, archives, history and more for your Porsche 914 ...