Oil pressure gauge drops to 0 at Idle


Alex911

FORD GT OWNER - FROM RUSSIA TT FGT
Mark IV Lifetime
Jan 22, 2008
73
Moscow, Russia
Well after the long winter conservation - the ice is off the roads and i took out my GT for a drive and took it for a checkup:

At idle - the oil pressure gauge on the dash suddenly fell to 0 and the Chek gauge lit up. I touched the gas pedal and the oil pressure went right back up - after that it was normal - but happened again yesterday.
The oil was changed, no errors light up on the SCT unit when I search for error codes.
Anyone have any idea where to start looking to fix that?

Another issue that I have discovered is that a bolt seal that attaches the lower cover of the engine to the block - dried out during the winter and was leaking oil - so better check those seals after a long winter stay. That problem was fixxed but i don't think it hd anything to do with the above!


Thanks a lot,
Alex!
 

RALPHIE

GT Owner
Mar 1, 2007
7,278
Well after the long winter conservation - the ice is off the roads and i took out my GT for a drive and took it for a checkup:

At idle - the oil pressure gauge on the dash suddenly fell to 0 and the Chek gauge lit up. I touched the gas pedal and the oil pressure went right back up - after that it was normal - but happened again yesterday.
The oil was changed, no errors light up on the SCT unit when I search for error codes.
Anyone have any idea where to start looking to fix that? !

Faulty Oil Pressure Sending Unit

Another issue that I have discovered is that a bolt seal that attaches the lower cover of the engine to the block - dried out during the winter and was leaking oil - so better check those seals after a long winter stay. That problem was fixxed but i don't think it hd anything to do with the above!


Thanks a lot,
Alex!

Mine is sequestered from November through April, but once a month (or more) I open the garage door and fire it up for ½ hour or so to (1) keep the battery charged up, (2) have the oiling system recoat internal engine moving surfaces, (3) eliminate internal condensation and (4) wet the engine seals. Also good to run the belts frequently.
 
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Alex911

FORD GT OWNER - FROM RUSSIA TT FGT
Mark IV Lifetime
Jan 22, 2008
73
Moscow, Russia
Faulty Oil Pressure Sending Unit



.

So it has nothing to do with the oil pump and I shouldn't worry about driving the car until I receive the new part?

Thanks
 

Indy GT

Yea, I got one...too
Mark IV Lifetime
Jan 14, 2006
2,526
Greenwood, IN
Alex-

As Ralphie states, I also believe it is a faulty oil sending unit. Search the Forum for previous discussions on this issue. I believe others have had a similar experience and I do not recall anyone posting up any technical results of an oil pump failure of any kind. Bill or Kendall might chime in as well.

Out of curiosity, how cold does it get in Russia (inside garage and outside air temp) while the car hybernates over the winter months? Not that I think this led to any of your problems, just curious.
 

Heffner Performance

*Supporting Vendor*
Supporting Vendor
Feb 22, 2006
367
Please do not assume that it is merely a faulty oil pressure sending unit. The first thing I would suggest is that you verify that the oil level is where it needs to be. So many people ignore the correct procedure for checking the oil level in a GT. If you have any questions please give me a call. I have pm'd you my cell phone number. Thanks.
 

Alex911

FORD GT OWNER - FROM RUSSIA TT FGT
Mark IV Lifetime
Jan 22, 2008
73
Moscow, Russia
Alex-

As Ralphie states, I also believe it is a faulty oil sending unit. Search the Forum for previous discussions on this issue. I believe others have had a similar experience and I do not recall anyone posting up any technical results of an oil pump failure of any kind. Bill or Kendall might chime in as well.

Out of curiosity, how cold does it get in Russia (inside garage and outside air temp) while the car hybernates over the winter months? Not that I think this led to any of your problems, just curious.

My car is parked in a heated garage where the temp is about 16C. Outside it gets down to about -25C but average is -5 -6 C
 

nota4re

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Feb 15, 2006
4,194
Please do not assume that it is merely a faulty oil pressure sending unit.

I agree with Jason. The fact that the "Check Gauges" warning light is illuminated along with the low reading, concerns me - and adds to the credibility of the 0 psi gauge reading. While the odds may be against a genuine loss of oil pressure, the consequences of assuming that it is only a gauge/sending unit can be too great. Check oil level first, and keep us posted on what you find.
 

kumar

GT Owner
Jan 31, 2007
1,011
Dallas
My car actually did this a couple of times when I first bought it. It even died on a couple of occasions.
 

red gt 1442

GT Owner
Mark IV Lifetime
Dec 23, 2005
754
NY Metro Area
My car actually did this a couple of times when I first bought it. It even died on a couple of occasions.

When I fist bough my car it did the same ( had about 1k on it)one day while in bumper/bumper traffic. At idle oil pressure down to zero, light on....bleeped it, and it went away. Happend twice within 5 minutes. At 5500K I have never seen it again.


Gino
 

Alex911

FORD GT OWNER - FROM RUSSIA TT FGT
Mark IV Lifetime
Jan 22, 2008
73
Moscow, Russia
Thank you all for the replies - will check the oil level again - already ordered the oil sending unit though - so I will replace it just in case.

P.S. I love seeing the expression on the spare-parts guy's face at the standart Ford dealer in Moscow - when he finds out about the existance of a Ford GT - next time taking the camera with me :)

Alex
 

Silverbullitt

GT Owner
Mar 3, 2006
1,757
Lago Vista, TX
Where did you get your oil filter? I bought as batch of mann filters on the internet and they displayed the same symptom. I went to a local auto parts store and bought a filter (stp) for a bmw 330i. Problem solved. Luckily mine was at 0 for less than 1-2 seconds at a time.
 

Blue Moose

GT
Mark IV Lifetime
Le Mans 2010 Supporter
Apr 12, 2006
1,139
Chandler,Arizona.
Battery?

Alex, you say "....after the long winter conservation." Could it be a week battery?

I had taken our GT out after being stored and the gauges including the oil gauge were at zero due to a very low battery.

The SCT unit would find it if it was, but just a thought.
 
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STORMCAT

GT
Mark IV Lifetime
Le Mans 2010 Supporter
May 25, 2006
7,551
Ft. Lauderdale
Thank you all for the replies - will check the oil level again - already ordered the oil sending unit though - so I will replace it just in case.

P.S. I love seeing the expression on the spare-parts guy's face at the standart Ford dealer in Moscow - when he finds out about the existance of a Ford GT - next time taking the camera with me :)

Alex

That would be a site to see.. Your signature should be " From Russia with Love " ...:biggrin
 

Jim

GT Owner
Mark II Lifetime
Jul 17, 2006
203
Michigan
Well now it happened to me today! I took the car to work and oil pressure was just fine - around 50 pounds normal pressure and was fine all the way to work (26 miles). After work, I jumped in, started it up and oil pressure was only 25 lbs. this was strange since it's typically 75 at cold start and then drops to 35-55 while driving. It hovered around 25 and then suddenly 2 blocks away at a light and at idle, it dropped to 0 and the red check gauge light came on - blipped the throttle and it went back up to 25 -35 pounds. Then it happened 3 more times during the next 5-6 blocks but then while on a steady state cruise at 35 mph it suddenly dropped to 0 again (all other guages were just fine) so I actually did a key off shut down and coasted to a stop down a side street totally discouraged! Got out, checked level - all was just fine. Got in and restarted and it was now 50-55 lbs and drove rest of way home (25 miles) no issues at all. 2400 miles on car. Any clues? is there an oil pressure relief spring/valve in this engine?:frown
 

shelbyelite

PERMANENTLY BANNED
May 10, 2007
1
As already stated, its more than likely the sending unit. That is the problem about 99% of the time when someone describes this exact issue.
 

Stef

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Apr 5, 2009
1,082
Southern California
I also believe the most likely culprit is the sender. My fleet of Diesel powered
work trucks on occasion have the same issue. The soot that builds up in the engine oil(no matter how much you change it) clogs up the sender's now and then making the idiot lights glow and gauges read low. Check everything, and replace the sender, I bet your problem will be history.
 

Jim

GT Owner
Mark II Lifetime
Jul 17, 2006
203
Michigan
Thanks for the help guys - I pulled the lower belly pans off and inspected the sender. The outer sleeve of the oil pressure sender is loose - it rotates 1/8" turn back and forth along with the connector. Hope this is the problem. I have a new one on order ($38.00) and waiting for it to come in. I will try to plumb in a mech gauge to validate it. Talked to Rich of the GT Guys and he said he has seen several customers with same symptom as mine.
 

Jim

GT Owner
Mark II Lifetime
Jul 17, 2006
203
Michigan
You guys were right - it was the oil pressure sender. The old sender could "twist" about it's centerline - the shell of the sender about 1/8" like it was loose from the housing when I pulled it out. New part: 4G7Z-9D290-AB which cost $35 fixed it and oil pressure is now 75 at start , 50 at cruise and 40 at idle.

I am relieved! Thanks :banana
 

Neilda

GT Owner
Oct 19, 2005
3,559
London, UK
Just out of curiosity only, was that a 'regular' Ford part or a special GT only part?

Glad you got your car fixed...
 

Jim

GT Owner
Mark II Lifetime
Jul 17, 2006
203
Michigan
Since it has 4G7Z (Ford GT service part prefix) , yes, I would say this is a special unique Ford GT sensor. I plan to buy a spare.