No oil pressure at start-up?

[Sitting Bull]

97 xj, 4.0 AT, 100k

When I start the Jeep, I have no oil pressure for about 5 seconds. Then it takes off and idles at 40 (while cold) and seems to be running perfect. I've changed the sending unit - had no affect.

Any advice???

 

[Midnight Krawler]

You might have a bad oil filter. Try changing it but stay away from Fram.

 

[Ridr]

beat me to it LOL take off the Fram filter , it uses a cardboard valve

 

[majic_tech]

what weight oil are you using?
I use 5-30 kendall semi synthetic with 200k and it has good pressure when warm no oil starve issues at cold startup

 

[Sitting Bull]

y'all were right. I changed the oil filter and the problem went away.

Thanks!!!

 

[Rick Anderson]

Its called an Anti-Drain Back Valve, its the rubber diaphram you see inside the oil filter when you look into those little holes drilled around the circumference. When you shut off the engine, it closes and prevents the oil in the motor from draining back into the pan. Thus when you start the motor you get oil pressure immediately and not 5 seconds later as the oil pumps all the air out of the system.

FRAM filters have Carboard End Caps glued on the filter cartridge ends, the Anti-Drain Back Valve seals against the End Caps of Filter Cartridge, and Rubber does NOT seal well against Cardboard.

The cheap ORANGE FRAM filter is probably the only filter made that uses the cardboard end caps, all the others use metal, which rubber seals against quite nicely. As well, the Carboard End Caps can come apart and get pumped into the motor and cause damage by clogging the oil journals. Rare but it never happens with other filters, Cheap ORANGE Frams, it happens sometimes which is WAY, WAY TOO MUCH.

 

[creepinjeepin]

I've almost have the same problem but when I start driven the oil pressure goes between 10 and 20 when I stop it drops to 0. Any answers. Sometimes it will stay around 40. IF someone could help out. Thanks

 

[BCKNBLK]

IMO.....NAPA Gold oil filters, always work great, has anti drainback, promotes good pressure.

 

[Rick Anderson]

I've almost have the same problem but when I start driven the oil pressure goes between 10 and 20 when I stop it drops to 0. Any answers. Sometimes it will stay around 40. IF someone could help out. Thanks

Thats low oil pressure. What engine, how much mileage and what condition is the motor? Has it been doing this for a while or did it just start happening?

Usually low oil pressure comes from wear, if you can only get 10-20 PSI while driving with the gauge dropping to zero at idle, than your motor is shot OR you have some sort of oil system problem, the former the most likely.

When do you get the 40PSI, just after starting up in cold weather while the motor is cold?

You could try switching to a higher viscousity oil to raise the oil pressure a bit, but its sounding like your motor is due for a rebuild.

 

[TiRod]

I've used the ORANGE filter, had oil psi problems, threw a rod, rebuilt the engine, had MORE oil psi problems, and switched to anything but ORANGE filters. Never had a problem since.
That truck was subsquently damaged by a tornado - I sold it to a nice young man who needed a new engine because his spun a rod bearing. He was using an ORANGE filter.
On the Jeep 4.0, especially the older ones with an upside down mounting, use a good brand with an anti-drainback gasket. It appears as a "reddish" rubber gasket inside the filter under the round holes. (Ok, maybe it looks orange.)
But not the ORANGE filter. Not on my Jeep or anything I own.

That engine cost me $1800, which would pay the $2 difference for 900 better filters.

Either a new pump or a Teflon additive can raise oil pressure.

 

[Rick Anderson]

The manufacturers use different materials for the anti-drain back valves, some are silicone, others are varous forms of rubber. So some will be red/orange or black, just stick to a good quality oil filter.

Which the Orange Painted FRAM filters are NOT.

I use Hastings Filters.

 

[Tweeternpi]

What about the Fram Tough Guard Filters are they any better?

 

[Midnight Krawler]

If your having low oil pressure problems, first thing to do is change your oil filter. Especially if it is a Fram!! If this doesn't work, ether change your oil sender unit or check the pressure by a mechanical gauge to determine if your engine really has low oil pressure. Sending units are knowing to go bad and/or get plugged up. Verified low oil pressure usually is a result of worn bearings or a plugged up oil system. Sometimes a higher viscosity oil will raise the pressure, something like a 20-50 weight with some "Restore" will help. My manual says for 10-30 weight oil 13 psi at a warm idle and 37 psi above 1600 rpms is normal.

 

[MG_43]

NO FRAM OF ANY KIND! THEY SUCK! BUT IF YOU LIKE TO PEPLACE ENGINES, GO FOR IT.

 

[Rick Anderson]

What about the Fram Tough Guard Filters are they any better?

Actually, they've cut those open and they seem to be higher quality than the ORANGE Painted Filters, BUT THEY STILL HAVE CARDBOARD END CAPS.

Check out this web site, it is very illuminating as too the quality of many of the filters you purchase out there.

http://minimopar.knizefamily.net/oilfilterstudy.html#fram-ph8a

 

[Tweeternpi]

Thanks for the link. I will be changing my filter this weekend. Motor has almost 200,000 and runs great, do not want it to die because of an oil filter.