Oh great, another gauge failure.


RALPHIE

GT Owner
Mar 1, 2007
7,278
...Has anyone ever had oil pressure fail while driving?....

Twice - both times the oil pump failed and twisted off the oil pump drive shaft. Makes a hex drive shaft look like a twist drill.

View attachment 32760
 

Lorenzo

GT Owner
Mark II Lifetime
Dec 28, 2008
626
U.S.A.
No gauge fails, but I would drive even if they all failed. If I was inclined to wait years for a mythical Autometer solution, I'd just plug a ScanGauge into the OBDII port. Speed, rpm, temp, volts...anything reported to the OBD. Not sure about boost or oil pressure, but who needs those? Has anyone ever had oil pressure fail while driving? I guess anything is possible, but risk is miniscule. Greatest risks are flat tires (nobody seems to mind not having TPMS) and backing into a curb (no reverse camera).

In My Opinion, I believe there is slightly more of a chance that a FGT could loose oil pressure as opposed to a conventional ( None Dry Sump ) type engine with an internally driven oil pump for the simple fact that our engines relay on belt to drive an externally mounted pump. With proper maintenance as you said it's Miniscule But with that in mind it's the reason I change the belt every year regardless of miles.
 

Xcentric

GT Owner
Mark II Lifetime
Jul 9, 2012
5,213
Myakka City, Florida
Twice - both times the oil pump failed and twisted off the oil pump drive shaft. Makes a hex drive shaft look like a twist drill.

That would be enough to turn me into a certified paranoid. :/
 

GTdrummer

GT Owner
Mark II Lifetime
Le Mans 2010 Supporter
Mar 13, 2010
2,122
Richmond Virginia
Twice - both times the oil pump failed and twisted off the oil pump drive shaft. Makes a hex drive shaft look like a twist drill.

View attachment 32760

Could have gone all day without seeing that. How about Jeff? Any similar failures?
 

RALPHIE

GT Owner
Mar 1, 2007
7,278
Could have gone all day without seeing that. How about Jeff? Any similar failures?

Terry - this wasn't on my GT, rather it was on my 1966 Mustang 289. First time in 1984, second in 2011.

I just wanted to answer the question regarding any oil pressure failings. Both times, I was in my driveway when the failure occurred, noticed the pressure go to "0" and shut it down without damage.
 
Last edited:

GTdrummer

GT Owner
Mark II Lifetime
Le Mans 2010 Supporter
Mar 13, 2010
2,122
Richmond Virginia
Lawyers never read things carefully. I feel better
 
Could have gone all day without seeing that. How about Jeff? Any similar failures?

This problem is well known. In many Ford V8s the oil pump is driven by a quill from the bottom of the distributor. That quill occasionally fails. I'm no expert, but for a variety of reasons I would doubt such a failure would occur in a GT motor.
 

Sinovac

GT Owner
Mark II Lifetime
Jul 18, 2006
5,862
Largo, Florida
Totally different design with the FGT's oil pump drive. The main problem thus far hasn't been with the belt itself, but with the belt pulley.
 
Last edited:

FBA

GT Owner
Dec 5, 2010
1,672
31.022340° N / 44.846191° W
I just ordered the complete Speedhut cluster. It also comes with the black insert, so I don't have to modify the original one! Ordered the legacy boost gauge with the sending unit so now, I'll get the real boost pressure readout in the cluster! Thank god!
 

RALPHIE

GT Owner
Mar 1, 2007
7,278
This problem is well known. In many Ford V8s the oil pump is driven by a quill from the bottom of the distributor. That quill occasionally fails. I'm no expert, but for a variety of reasons I would doubt such a failure would occur in a GT motor.

The clearances in the oil pump of the 289 OHV engine are extremely small, so, if a small particle (smaller that the pickup screen openings) enters the pump, it locks it up. The failure then happens as the pump stops and the camshaft and driven distributor keep turning, twisting the intermediate drive shaft. The last time, I replaced it with an ARP drive shaft, although, if it happens again, I'm afraid it will transfer the problem to a more expensive location. As a safety precaution, I install a new oil pump each time.

I agree that the GT motor would not have such a failure, but I agree with Lorenzo that a working oil pressure gauge is extremely important, not only because of the belt drive, but for any failure that might occur in the oiling system. The two gauges I feel are most important to any engine's livelihood are the oil pressure, and the oil temperature (not the water temp). Unfortunately, we only have one of these. A ammeter or voltmeter tells us the condition of the electrical system's operational status, and the water temperature lets us know if the cooling system is working [i.e, the coolant (water) pump is running]. A tachometer used to be a precautionary gauge to prevent overrevving an engine, but today's electronics seem to do this well enough, yet for racing, it helps us gauge our shift points. Speedometers are only necessary to let one know that we have entered the speed zone where we might be doing something unlawful. Regarding a boost/vacuum gauge, the only time I've looked at mine is when cruising, in order to keep the vacuum level high and thus get the best efficiency (fuel mileage) - If I'm in the boost range, my eyes are looking out the windshield, which seems more important at that time.
 

the Wizard

GT Owner
Jul 16, 2012
414
Los Angeles
SpeedHut is gonna have a sale in March.....

FBA....is installing the sensor and routing the pressure line pretty easy?
 

jbyrnes

FORD GT OWNER
Mark II Lifetime
Jun 13, 2006
224
Louisville CO
Years ago I built up my 68 GT-350 with a heavily modified 69' BOSS 302 motor. To protect my investment I wired the ignition through the oil pressure idiot light sensor which activates at about 5 psi so if I lost oil pressure the motor would quit. Worked great, but had the added hassle of needing to add an under-dash override switch for starting the car so the motor wouldn't have to crank too long to build up enough oil pressure before firing. But with today's electronic systems, software, and sensors it seems it would be simple to have ignition cutoff w/o oil pressure functionality, without the starting issue.
 

BlackICE

GT Owner
Nov 2, 2005
1,416
SF Bay Area in California
But with today's electronic systems, software, and sensors it seems it would be simple to have ignition cutoff w/o oil pressure functionality, without the starting issue.
I had an 88 Vette that did that with a starting motor override. No oil pressure and the fuel pump are turned off.
 

FBA

GT Owner
Dec 5, 2010
1,672
31.022340° N / 44.846191° W
SpeedHut is gonna have a sale in March.....

FBA....is installing the sensor and routing the pressure line pretty easy?
I guess I'm gonna find out! I believe the only PITA will be crossing through the firewall; the rest should be be simple.
 

the Wizard

GT Owner
Jul 16, 2012
414
Los Angeles
How soon are you gonna do this?
 

twobjshelbys

GT Owner
Jul 26, 2010
6,189
Las Vegas, NV
I just ordered the complete Speedhut cluster. It also comes with the black insert, so I don't have to modify the original one! Ordered the legacy boost gauge with the sending unit so now, I'll get the real boost pressure readout in the cluster! Thank god!

I'm curious how a direct reading boost gauge goes in. Is there a port on the supercharger for a sensor and sending unit? I'm guessing the connection to the instruments is a wire (not a live pressure tube), but where do you route it? Detailed instructions in a "how I did it" topic would be a great help.

I'm interested because the configuration I have offsets the stock boost gauge and so fare there hasn't been a "cheating" way to recenter it. So it's out, but it doesn't read right anyway so maybe the best solution is to just go with Speedhut.
 

BlackICE

GT Owner
Nov 2, 2005
1,416
SF Bay Area in California
Only wires need to be routed. Follow the shifter cables through the firewall and inside the center tunnel, under the radio and then to the gauges. Be sure to tie wrap the wires away from the belts.
 

FBA

GT Owner
Dec 5, 2010
1,672
31.022340° N / 44.846191° W
How soon are you gonna do this?
Not till April; we have a few feet of snow and it's getting done at the performance shop when I get my pulley/ intakes done. I don't feel like doing it myself, so I'll wait. From what B/I just posted, doesn't seem that tough. Seems like changing the cluster is actually more work.
 

ByeEnzo

GT
Mark IV Lifetime
Le Mans 2010 Supporter
Dec 10, 2005
2,299
Fort Worth, TX
No gauge fails, but I would drive even if they all failed. If I was inclined to wait years for a mythical Autometer solution, I'd just plug a ScanGauge into the OBDII port. Speed, rpm, temp, volts...anything reported to the OBD. Not sure about boost or oil pressure, but who needs those? Has anyone ever had oil pressure fail while driving? I guess anything is possible, but risk is miniscule. Greatest risks are flat tires (nobody seems to mind not having TPMS) and backing into a curb (no reverse camera).

Anyone have oil pressure fail while driving? Why yes...damn near to 0 PSI.

http://www.fordgtforum.com/forums/showthread.php/19626-Failed-oil-pump-pulley-the-sad-saga-of
 

Xcentric

GT Owner
Mark II Lifetime
Jul 9, 2012
5,213
Myakka City, Florida
I read a bit of that thread. Did the oil pressure gauge save you, or did the oil starved clattering noise save you?

I'm not trying to say gauges aren't needed. But the question was, does anybody drive with failed gauges? I'd say, if power train failures were rank ordered, oil pump failure would be very low on the list. Pure speculation on my part, of course. I'd still drive without any gauges. That stuff only happens to other people. :biggrin