72MachOne99GT

Brother has a mid 50K mile '98 Cobra that had its oil changed roughly 70 mikes ago at Jiffy Lube (don't ask why....I have no clue why he would take it somewhere and not ****ing do it himself).

2 days and the aforementioned miles later he said the oil pressure just plummeted. I don't know all the details but this happened a few miles after a loud sound was heard while driving.

Upon investigation the drain plug and filter both appeared to be seated properly. The underside of the motor (driver side) was coated in oil. According to my dad, the oil didn't appear to have escaped.from the plug or pan, nor the filter.

He mentioned a weep hole dripping slowly from the block that the filter attaches to against the engine block, but nothing crazy.

Refilled car with oil and ran while on blocks. No spray, no leaking, no signs of oil going anywhere.

Ideas? I think today we are going to replace the gasket that fits between the block and the assembly that the filter attaches to as I've replaced it on my 99 GT for leaking before. Anyone had a similar experience?

dawson1112

So after the oil refill did the oil pressure return to normal?

I recommend degreasing the engine to remove all trace of oil, then run the car and look for leaks.

l Steveo l

Any change in engine noise? Knocking, grinding, etc.? Possible to have a bad oil pressure sensor. I can't remember 100% but I believe the oil pressure sensor is fairly close to the oil filter on the 4.6Ls. I know I broke the wire on an Expedition several years back when using a oil filter wrench. Someone could have pulled it just enough to where it contacts intermittently.

I mean we all know Jiffy Lube has ASE certified mechanics that specialize in rocket science on their off days.

72MachOne99GT

It definitely lost oil. The road was covered as well as the bottom driver side of the motor.

The car was refilled, oil pressure returned to normal and there didn't seem to be any leaks.

What we did discover yesterday was that the threaded stud/bolt/whatever that the filter physically threads onto was lose, and certainly NOT torqued to 45ft/Lbs as it is supposed to be.

My guess is this may have allowed the filter to seal improperly causing a leak.

today hes going to torque it to 45 ft pounds, see if the weep hole stops leaking on the cooler and go from there.

l Steveo l

Double gasket on the filter? I know that may sound like a dumb question, but hey, it's happened to people before. Normally that leaks/spews oil the second you start it up, but it could have had just a good enough seal to hold everything until something caused the seal to break loose.

dawson1112

I can pretty much tell you what happened....

Who ever changed the oil before put the filter on way to tight, when jiffy lube took it off it loosened the oil filter bolt in the center and they either did not notice it or ignored it.

72MachOne99GT

Hoping it's something like that.

uberstang1

Hoepfully oil pump didnt crap

JC316

Agreed. Lube techs are at best functional morons. I have fixed two double gaskets from oil shops.