Oil Pressure Woes...

[Shirley]

Every day it is something new with these damn cars. Ok I live in AZ. The temp right now is low to mid nineties. I am using mobil synthetic 10w-30. I had to put a new shortblock in about 8 months ago because the motor lost oil pressure on the highway, and spun #1,#5 main bearings. My oil pressure gauge as of right now when the car starts up oil pressure is above the middle mark, but as the engine heats up, or during spirited driving, the gauge reads no higher than the "A" in NORMAL. This is basically the same symptom I had right before the last motor lost oil pressure. I'm getting pretty nervous right about now. I know the stock gauges are crap, but what checks can I make to see if I have a problem. Or do I have a problem in the first place? I was reading how the oil pump driveshaft is another weak link in the 5.0 engine. ANY THOUGHTS?

 

[KDK1988GT]

i woud say

I would say invest in a good gauge.... so u will have a dead on reading

I'm not sure of any test that u could do

change the sending unit that might be messing with the reading also... try that 1st

 

[Shirley]

is the sending unit the cylinder located right next to the oil filter?

 

[I8URVTEC]

The oil pressure sending units are prone to going bad. Before driving yourself crazy get a good mechanical oil pressure guage and make sure you really have a problem. I took a picture of where the sending unit is located but it was with a camera phone so hopefully you can see it.

 

[KDK1988GT]

yeh that would be it... just above the filter kinda...

what year is your car?

 

[KDK1988GT]

here is a pic.....

 

[KDK1988GT]

woops did not see the other pic....

 

[Shirley]

thanks for the pics guys, thats where I thought it was at, j ricker said something a while ago about hooking up a T- vacuum line, and then hooking up a mechanical gauge to that. Anyone know how I would go about doing that, or if JRICKER is online I need your all-knowing knowledge!

 

[Shirley]

someone asked what year my car was, its a 91 lx hatchback, black as the night itself.

 

[DMAN302]

I8URVTEC...me thinks you may have yourself an oil leak.

 

[Shirley]

The only oil leak I know of is the rear sump bolt. It leaks around literally 2-5 drops per day.

 

[KDK1988GT]

I'm sure there are more kits or setups out there other than this one but if you could rig something up like this..

http://shop.store.yahoo.com/brandsplace/0246-kd-3289.html

 

[Dbeck002]

Your problem is not the pressure sending unit. People need to stop blaming the gauges, the man already said he spun two bearings so there is an inherent problem there.

I would try using a thicker oil and see if that helps, who built your engine?

 

[Shirley]

this is the new motor with a new oil pump. I just don't want the same thing to happen again. The shortblock had 90,000 miles on it from an f-150, but the oil pump was new. I had a reputable shop install the motor for me, a place called sundevil auto.

 

[HISSIN50]

For JR's install, you would just Tee into the stock sender location like you would if adding an interior gauge. The only real difference (as I understand what he did) is that the gauge remains under the hood.

The stock sender is 1/4" NPT thread. Most aftermarket senders are 1/8" NPT so you will want to hit the home store to adapt fittings, get a tee, etc . If you add an elec gauge, you might need an extension line from the hex tube (I used a 1.5" one - to get the senders away from the motor). Then use a Tee (either 1/4 or 1/8" NPT). You can do it many ways so you just piece it together as you see fit. The home store should have all the fittings you need.

The only part I dont know is where JR gets his gauges (where in the home store). Where-ever they have hydraulic pressure gauges I would guess......

Good luck.

 

[sgarlic]

The stock sender is 1/4" NPT thread. Most aftermarket senders are 1/8" NPT so you will want to hit the home store to adapt fittings, get a tee, etc . If you add an elec gauge, you might need an extension line from the hex tube (I used a 1.5" one - to get the senders away from the motor). Then use a Tee (either 1/4 or 1/8" NPT). You can do it many ways so you just piece it together as you see fit. The home store should have all the fittings you need.

Just to add on to what JT said, the parts you would need for this are a brass 1/4" NPT Tee-Fitting, 1/4" close nipple (an inch or so long threaded tube,) some teflon tape, and the gauge. All this can be bought from Home Depot for about 5 bucks.

The autometer oil pressure gauge comes with a 1/4" -> 1/8" adapter piece (the last 2 I bought did at least.) After you wrap the nipple and the adapter piece with teflon tape, thread the nipple in to one end of the T fitting. Screw that in to the actual hex piece thing. Screw the adapter that comes with the autometer gauge in to the T fitting, snug it down with a wrench, then wrap the threads of both the factory and the autometer sender with teflon tape, and thread them in to whichever end you feel like. You can screw the sending units in to the T hand tight and they'll be fine, I've never used a wrench to tighten mine for fear of damaging the threads, and I've never had a leak yet.

If you prefer extra clearance, you can piece together elbows, nipples, etc (all from the plumbing dept. at home depot,) to however you feel like making it.

 

[wazazzle]

i had oil pressure probs too. i decided to replace the sending unit, clean the oil sending shaft, and switch to 20w-50. no more prob now, runs great! switch the sending unit and clean the shaft first. if that don't help go thicker oil.

 

[vristang]

i had oil pressure probs too. i decided to replace the sending unit, clean the oil sending shaft, and switch to 20w-50. no more prob now, runs great! switch the sending unit and clean the shaft first. if that don't help go thicker oil.

I had all kinds of trouble with 20w50. I had to switch to 5w20 to get consistent oil pressure. But there are a ton of factors that determine oil viscosity requirements.

jason