Oil pressure problem after oil change


Justin

GT Owner
Jun 30, 2013
27
Massachusetts
Took my 2006 to get the oil changed today to the local dealer. Picked it up, drove it out if the lot, oil pressure drops to zero at first stop light. Car sounded fine, and pressure shot back to 25psi when i hit the gas. Took it right back to dealer and they cannot figure out the problem. They said they primed it per the instructions several times and the oil is at the proper level. The tech says he doesnt think it is priming. But the guage does go to 25 at throttle then drops to zero at idle. Next step I guess is removing the sending unit and reading the pressure with a direct guage. Any ideas how a sending unit would go bad, or i suppose the gauge itself, just from an oil change? Im presuming the tech isnt correct in his assertion that its failing to prime.
 

fjpikul

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Jan 4, 2006
11,507
Belleville, IL
Many posts here about the sending unit going bad. Cheap and easy fix; or - filter not seated correctly.
 

analogdesigner

GT Owner
Mark IV Lifetime
Nov 15, 2005
949
San Clemente, CA USA
Many posts here about the sending unit going bad. Cheap and easy fix; or - filter not seated correctly.

Yes, I'm on my third sender! I now keep a spare one just in case!

Keep us informed, Jay
 

nota4re

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Feb 15, 2006
4,200
Hard to imagine that it had anything to do with the oil change. Car should take exactly 9.5 quarts to fill. Check fill level AFTER running and within 30 seconds of engine shut-off.
 

Justin

GT Owner
Jun 30, 2013
27
Massachusetts
Actually I have recently replaced the gauge itself after the oem gauge failed this winter. So if its anything with the electronics I agree its likely the sending unit. Now I have to find one! The dealer can get one Monday they think... Thanks.

Hate going to dealers. I drop off the car, as I'm about to leave I see my car being pushed backwards by one of the techs with one in the car. Guy has two hands on the hood pushing as hard as he can. I walk over and ask what is wrong. Guy says, 'reverse doesnt work.' Ok.... I said uh, you know how to drive a manyal right? Guy is like oh yeah, but this car has no reverse. Ford factory trained technicians. So when my oil gauge goes to zero driving it off the lot I suppose I was skeptical as to wtf they did��.
 

Specracer

GT Owner
Mark IV Lifetime
Nov 28, 2005
7,090
MA
The very few times I've taken the car to the dealer, they didn't want to move it. I did all the driving.
 

GKW05GT

GT Owner
Mark II Lifetime
May 28, 2011
2,755
Fayetteville, Ga.
The very few times I've taken the car to the dealer, they didn't want to move it. I did all the driving.

That is what I do with my local dealer and the only time I have been there is for the airbag replacement.
 

NorthwoodGT

GT Owner
Jun 12, 2009
1,215
Michigan
It's so important to find a Ford dealer who has a specific tech for working on GTs, Shelbys, etc. I hate it too but when you have to, you have to. I'm fortunate my dealer has several GTs they take care of including their own. "No reverse in this car"-now that's scarey! the gauge wouldn't crap out right after an oil change. does sound like a sender to me. the priming issue should work itself out once the system has been running I would think. see if Rich has any input.
 

GT Venum

GT Owner
Mark II Lifetime
Dec 4, 2010
326
Wisconsin
Does anyone have the part number for the oil sending unit?
 

ByeEnzo

GT
Mark IV Lifetime
Le Mans 2010 Supporter
Dec 10, 2005
2,284
Fort Worth, TX
Check the oil pump pulley also. Prior to completely melting down a worn pulley will cause fluctuating oil pressures. I just changed my oil last weekend and always pull the cover off the oil pump belt and tensioner assembly in order to check for any play etc.
 

JOEA2

GT Owner
Mark II Lifetime
Aug 16, 2007
352
STATEN ISLAND,NY/SEA GIRT,NJ
The local Dealer asked me not to bring my car back.

Joe
 

Justin

GT Owner
Jun 30, 2013
27
Massachusetts
I think this dealer is going to ask me the same thing! Thanks for the help. The dealer I have had the best luck with is Tasca in Rhode Island but I don't really want to drive over 100 miles for an oil change. What I found most disappointing is hardly anyone in the service department even knew what a Ford GT is!

The part number is posted previously on the forum, but it is 4G7Z-9D290-AB. It crosses to standard motors PS-442, and to several other part numbers. However I cannot locate one locally. So it looks like it spends the weekend in the dealer's service bay.
 

soroush

Ford Gt Owner
Mark II Lifetime
Aug 8, 2007
5,256
Actually I have recently replaced the gauge itself after the oem gauge failed this winter. So if its anything with the electronics I agree its likely the sending unit. Now I have to find one! The dealer can get one Monday they think... Thanks.

Hate going to dealers. I drop off the car, as I'm about to leave I see my car being pushed backwards by one of the techs with one in the car. Guy has two hands on the hood pushing as hard as he can. I walk over and ask what is wrong. Guy says, 'reverse doesnt work.' Ok.... I said uh, you know how to drive a manyal right? Guy is like oh yeah, but this car has no reverse. Ford factory trained technicians. So when my oil gauge goes to zero driving it off the lot I suppose I was skeptical as to wtf they did��.

Im shocked you still allowed them to work on the car after that! but as others have said your problem is not a big deal many cars including my blue car suffer from the same symptoms, at idle sometimes it drops to zero but as soon as you get going the gauge starts reading the pressure, Im ok as long as I know there is oil pressure and I have lived with this for many years no need to replace anything until the gauge or the sending unit quits completely.
 

Specracer

GT Owner
Mark IV Lifetime
Nov 28, 2005
7,090
MA
I see you are in Westborough, Roketman lives in Acton, and he had had work done at Acton Ford. Might want to PM him to see if he has had good luck with them, and what level they have helped him with (work past the simple airbag swap).
 

NorthwoodGT

GT Owner
Jun 12, 2009
1,215
Michigan
as mentioned above PN 4G7Z-9D290-AB dealer cost $21.36 SRP 42.72 16 in inventory at FCSD. I stock them as well if you have problems getting one.
 

shesgotlegs

GT Owner
Mark II Lifetime
Jul 20, 2006
1,181
Im shocked you still allowed them to work on the car after that! but as others have said your problem is not a big deal many cars including my blue car suffer from the same symptoms, at idle sometimes it drops to zero but as soon as you get going the gauge starts reading the pressure, Im ok as long as I know there is oil pressure and I have lived with this for many years no need to replace anything until the gauge or the sending unit quits completely.

Given that the system is faulty I'd be fearful of not having it serviced rather soon.
 

texas mongrel

GT Owner
Mark II Lifetime
May 3, 2009
1,664
Houston Texas
Actually I have recently replaced the gauge itself after the oem gauge failed this winter. So if its anything with the electronics I agree its likely the sending unit. Now I have to find one! The dealer can get one Monday they think... Thanks.

Hate going to dealers. I drop off the car, as I'm about to leave I see my car being pushed backwards by one of the techs with one in the car. Guy has two hands on the hood pushing as hard as he can. I walk over and ask what is wrong. Guy says, 'reverse doesnt work.' Ok.... I said uh, you know how to drive a manyal right? Guy is like oh yeah, but this car has no reverse. Ford factory trained technicians. So when my oil gauge goes to zero driving it off the lot I suppose I was skeptical as to wtf they did��.

Which is exactly why my car has never seen the inside of a dealer, I do all the work myself. In fact right now is the first time anyone else has worked on it - its with GT guys getting some mods, please be gentle Rich!
 

Spirit

Heritage GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Which is exactly why my car has never seen the inside of a dealer, I do all the work myself. In fact right now is the first time anyone else has worked on it - its with GT guys getting some mods, please be gentle Rich!
Relax Dave, if there is anyone you can trust with your GT, it is Rich and Denis.
 

shesgotlegs

GT Owner
Mark II Lifetime
Jul 20, 2006
1,181
Relax Dave, if there is anyone you can trust with your GT, it is Rich and Denis.


Indeed!!!
 

TO AWSUM

Ford GT Owner
Mark II Lifetime
Jul 4, 2007
1,506
Niceville FL
Took my 2006 to get the oil changed today to the local dealer. Picked it up, drove it out if the lot, oil pressure drops to zero at first stop light. Car sounded fine, and pressure shot back to 25psi when i hit the gas. Took it right back to dealer and they cannot figure out the problem. They said they primed it per the instructions several times and the oil is at the proper level. The tech says he doesnt think it is priming. But the guage does go to 25 at throttle then drops to zero at idle. Next step I guess is removing the sending unit and reading the pressure with a direct guage. Any ideas how a sending unit would go bad, or i suppose the gauge itself, just from an oil change? Im presuming the tech isnt correct in his assertion that its failing to prime.

Justin you are taking the correct steps, oil pressure is nothing to mess with. Remove the sending unit and install a direct gauge like you suggested. That will tell you if the problem is a lack of oil pressure meaning a pump or belt or pulley is bad. If you have good pressure then it's probably the sending unit or dash gauge.