Hello,

I’ve been having this issue where the oil pressure gauge drops to zero and the oil light comes on while I’m driving.
This normally lasts a minute or two before the gauge goes back to regular numbers and the oil light goes back to off.

I never noticed any other symptoms or smoke or anything else that could be oil related and unusual.

Any guidance on how to troubleshoot the issue?

 

Yes!!

Locate the sensors. In the vicinity of the oil filter. Clean and tighten. One or both may be failing.
If the clean and tighten does not stabilize the OP guage numbers get NOs units.

Check David Boger at everydayxj as a source. Good guy and posts here from time to time.

Been there, replaced the sensor with a NOs unit from David. ,Fixed...

The sensors are grounds… Classic Jaguar issue, poor grounds! Owners responsible.

Carl

 

Good grounds are essential....

 

Check your oil level! My S3 doesn't have the original engine, but I think they have two senders; one for the gauge and one for the light. If they are both showing low/no oil pressure at the same time, I would believe them. If you have oil level at/near the full mark on dip stick, plumb a mechanical oil pressure gauge in place of one of the current senders and see what the actual pressure is. If your pressure is zero for "a minute or two", your engine should be rattling pretty good. That would be another symptom of zero pressure while driving.
Dave

 

Indeed, they do. I used the same wires for the two on my V8. Same sensors as well..

But, for sure oil level is primary. Agreed.

Carl

 

So I thought I’d post a follow up on this.

Turns out the engine oil level was just really low. I thought it was weird because at least during winter and spring, I barely had any oil leaks so I expected it to hold up on that level (silly me).

Filled it up with good Castrol oil and that issue is now gone!

 

How many miles a month do you usually drive it?

 

Has anyone experienced excellent oil pressure when starting 70psi but dropping to less than 15psi when hot. This occurred suddenly and despite changing pressure gauges, checking with an auxiliary gauge, changing oil filter and checking the pressure relief valve, the hot running pressure has not gone back to normal. Right now I'm suspecting a split oil pump casing but would like to here from others before removing the sump

 

Normal, or near normal oil pressure when cold and dropping to low pressure when hot is one of the symptoms of worn bearings/crank. I've never had a Jaguar engine, so I don't know what normal oil pressure should be, although by the gauge they put in the car I would guess 40-50psi hot at 2000rpm and about 20psi hot at 700-800rpm. 15psi seems just a little low, but only you would know what it was in the past. What is the pressure at about 2000rpm hot? I had a 1992 Suburban with TBI 350 that came from the factory with pump set at 28psi on the high way and 12psi at idle, had 172,000+ miles when I sold it. Engine quiet and had never been apart.
Dave

 

Aye, SBC's run on lower OP than other engines. The GM engineers go with volumn rather than pressure. They are pretty smart, and it works. Notmal Op at driving speeds in my LT1 are 40 PSI!!

One generic rule is 10 #'s per thousand RPM..

Carl