Notices
944 Turbo and Turbo-S Forum 1982-1991
Sponsored by:
Sponsored by: Clore Automotive

Oil pressure gauge needle flickers at idle

Thread Tools
 
Search this Thread
 
Old 10-17-2011 | 12:42 PM
  #1  
Lex_GTX's Avatar
Lex_GTX
Thread Starter
Racer
 
Joined: Nov 2010
Posts: 271
Likes: 55
From: Surrey, BC
Default Oil pressure gauge needle flickers at idle

Some advice is greatly appreciated from people that have seen more 951s than myself.

I've replaced the sender to the gauge as it would peg at over 5bar. The new sender works and gauge works fine except that at hot idle when it sits between 2 and 3 bar the needle flickers ever so often. It goes down to 2 then quickly flickers back up to 3. When driving it does not flicker and is around the 4-5 region depending on RPM of course.

Is this a common electrical issue with the gauge/wiring or more indicative of a mechanical problem with the OPRV?

Thank you in advance
Old 10-17-2011 | 01:03 PM
  #2  
savvas944's Avatar
savvas944
Instructor
 
Joined: Dec 2008
Posts: 183
Likes: 0
From: bahrain
Default

cracked oil pickup pipe in the sump?
Old 10-17-2011 | 01:07 PM
  #3  
s14kev's Avatar
s14kev
Rennlist Member
 
Joined: Oct 2010
Posts: 707
Likes: 21
From: Tennessee
Default

Mine does the same. I get the impression that this is normal.
Old 10-17-2011 | 01:09 PM
  #4  
Scott H's Avatar
Scott H
Three Wheelin'
 
Joined: Jan 2006
Posts: 1,620
Likes: 6
From: Orlando, FL
Default

Yup, this is one of those "nature of the beast" sort of problems. So either it's supposed to function that way, or all of us have some crappy grounds going to the gauge cluster.
Old 10-17-2011 | 01:19 PM
  #5  
Lex_GTX's Avatar
Lex_GTX
Thread Starter
Racer
 
Joined: Nov 2010
Posts: 271
Likes: 55
From: Surrey, BC
Default

I have some fun electrical issues that I am currently working through - low readings on the voltage gauge, some stumbling associated with this, even my engine temp gauge sometimes flickers a bit.

I just wanted to verify it's not a mechanical problem (ie it's common)
Old 10-17-2011 | 02:09 PM
  #6  
kinglenario's Avatar
kinglenario
Racer
 
Joined: Mar 2011
Posts: 433
Likes: 0
From: Atlanta
Default

Same here. Sometimes electrical load visually changes my oil pressure gauge. Less than 1/16" of movement but it happens. I think it's grounds. These cars even when new didn't have the strongest electrical system.
Old 10-17-2011 | 02:30 PM
  #7  
jerome951's Avatar
jerome951
Drifting
 
Joined: May 2002
Posts: 2,715
Likes: 79
From: Germantown, Maryland
Default

Originally Posted by Lex_GTX
I have some fun electrical issues that I am currently working through - low readings on the voltage gauge, some stumbling associated with this, even my engine temp gauge sometimes flickers a bit.

I just wanted to verify it's not a mechanical problem (ie it's common)
The oil pressure fluctuations sound normal, but you've got other issues going on. Clean the engine and body grounds (back of engine, firewall, and battery posts) and see if that resolves the problem.
Old 10-17-2011 | 02:58 PM
  #8  
Lex_GTX's Avatar
Lex_GTX
Thread Starter
Racer
 
Joined: Nov 2010
Posts: 271
Likes: 55
From: Surrey, BC
Default

Yes, I know I have to clean everything.

Is there a trick to getting to the main battery ground on the bellhousing? I cleaned the small ground (10mm) but the 13mm one from the DME and battery is very much tucked under the heater valve.
Old 10-17-2011 | 03:07 PM
  #9  
Ben951S's Avatar
Ben951S
Burning Brakes
 
Joined: Nov 2007
Posts: 1,242
Likes: 3
From: West Chester, PA / Morristown, NJ
Default

Don't forget the grounds under the dash... you know, the ones the cluster probably depend on... =)
Old 10-17-2011 | 03:33 PM
  #10  
kinglenario's Avatar
kinglenario
Racer
 
Joined: Mar 2011
Posts: 433
Likes: 0
From: Atlanta
Default

this is by far the best stuff on the market for cleaning electronics connections.

Caig Deoxit
Old 10-17-2011 | 06:24 PM
  #11  
Baptizo's Avatar
Baptizo
This didn't cost
me any drachmas
Rennlist Member
 
Joined: Sep 2010
Posts: 5,279
Likes: 8
From: The Land of FREEDOM
Default

At least your's is working, mine is now pegged out to the max and I need to replace the sending unit.
Old 10-17-2011 | 06:26 PM
  #12  
Lex_GTX's Avatar
Lex_GTX
Thread Starter
Racer
 
Joined: Nov 2010
Posts: 271
Likes: 55
From: Surrey, BC
Default

Originally Posted by derekc23
At least your's is working, mine is now pegged out to the max and I need to replace the sending unit.
Had that issue a couple of days ago so I already replaced mine. I am dreading the removal of the 13mm ground on the bellhousing.
Old 10-17-2011 | 06:41 PM
  #13  
Baptizo's Avatar
Baptizo
This didn't cost
me any drachmas
Rennlist Member
 
Joined: Sep 2010
Posts: 5,279
Likes: 8
From: The Land of FREEDOM
Default

Originally Posted by kinglenario
this is by far the best stuff on the market for cleaning electronics connections.

Caig Deoxit
Thanks for the link!
Old 10-17-2011 | 06:59 PM
  #14  
kinglenario's Avatar
kinglenario
Racer
 
Joined: Mar 2011
Posts: 433
Likes: 0
From: Atlanta
Default

no problem. i need to try getting on to those bell housing grounds and loosening them and getting some de-oxit on there. can they be loosened a little without too much trouble? With that caig stuff you don't really need to brush it.

i use that stuff all the time, especially to keep this lathe running (below). it's german too. porsche should have taken their lead on the electronics though!

Neumann Lathe
Old 10-17-2011 | 07:34 PM
  #15  
supes6's Avatar
supes6
Racer
 
Joined: Mar 2009
Posts: 487
Likes: 0
Default

Mine flickers sometimes too... even with a new sender and mostly new engine harness + battery cables.



All times are GMT -3. The time now is 02:39 PM.