oil pressure issues

hi

can anyone tell me some of the potential causes for no oil pressure in a 91 RS...it starts out with the gauge at half way and slowly decreases until it remains at 0....all obvious checked no leaks on ground or seen in engine, had oil replaced....still same.

HELP
thanks
Shawn

have the same car of the same year, oil pressure gauge doesn't work right, when i sit idle it'll bounce around all over the place, when i hit the gas, it'll just bury to the max and stay there till i come to a stop, when i change oil and first start it, it'll be zero, then start jumping around when the pressure comes back. so you prolly just have a faulty gauge like i do.

well i would have to ask, do you hear ticking from the engine??? do you hear a bearing noise coming from the engine, any indicators that the engine is not getting propor lubrication??? run the engine with the proper ammount of oil in it. immediately after shutting off the engine, check the oil, if the pan is still full, your not lubing the top end. and you have a faulty oil pump. or some sort of material clogging the pickup filter. if your gettin proper lubrication then its a faulty oil pressure guage, or a faulty oil pressure sensor.

I have checked enginge oil after running....the oil read full, and there did seem to be this ticking noise coming from the enging...what am i looking at, where can i locate the pump and filter you mentioned earlyer?

sometimes the ticking is normal, check to see if it speeds up with engine speed, if it gets quieter with higher rpms, and grows louder after sitting at idle for a period of time, if all of these are true, it sounds like a lubrication problem, and you need a new oil pump more than likely. not a guarantee by any means, but my best bet baised on the info at hand.

as for the pump and filter, both are inside the oil pan. the pump is driven by a shaft on the bottom of the distributor, and bolts to the bottom of the block with two bolts, the filter is also inside the oil pan, also known as the oil pickup. to get to these you will have to drain your oil, and remove the pan, undo the two bolts holing the unit on, and pull it off. put in a new one, and put it all back together with a new oil pan gasket.

Hi
I just joined!
I have the same car with the same symtoms, and if I turn off my car
while the pressure reads "0" my car will not start (temperarally). I've purchased an oil pressure switch to hopefully solve this problem... However, I dont know where the part is located on the car!
Does anyone Know ??

There are two possible locations for the oil pressure sender: Just above the oil filter or behind the distributor. If your gauge is indicating low oil pressure, the best thing to do is install a mechanical pressure gauge. The installation can be temporary just to find where the problem is. Use a tee connector for a permanent install, or just leave the sender out for a temporary pressure check. If the mechanical gauge is indicating low oil pressure, the engine is in need of major work - oil pump, bearings, etc. A band-aid fix for this is to use heavier oil (20w50) to boost the pressure a little. It won't flow out of loose bearing clearances as fast, and won't 'bypass' worn pump gears as much. It won't help if an oil gallery plug popped out inside the timing cover. That will kill the oil pressure and you won't see the leak since it drains back into the pan. If that's the case, you won't have oil pressure at all, even when the engine is cold. In any case, serious engine damage will occur with inadequate oil pressure, so make sure there are no internal oil pressure problems with the engine!

Dan

91 rs camaro

do you lose pressure immediately or do you go for a little while with full pressure and then lose it all? If so does the car feel sluggish after losing pressure?

Does anyone know if no oil pressure can possibly result in a loss in MPG of gas???? Because i seem to be getting very very low miles to the gallon of gas.

thanks
shawn

1991camaroRS STOP DRIVING IT!!!!!!! if your fuel economy is dropping, its very possible that you have no lubrication, or very little, and the increased friction of the rotating assembly with no oil is robbing power, and gas mileage, so untill you figure this one out, dont start it anymore.

91 rs camaro

do you lose pressure immediately or do you go for a little while with full pressure and then lose it all? If so does the car feel sluggish after losing pressure?

Does anyone know if no oil pressure can possibly result in a loss in MPG of gas???? Because i seem to be getting very very low miles to the gallon of gas.

thanks
shawn


1991 camaro RS, dxrflyboy,

When I start the car , my pressure gauge will flutter between 50%-100%.
After the car warms up, the gauge will flutter between 0%-50% (sometimes it just sit's at "0" with my foot on the clutch).
when I give the car gas, the gauge reads close to 100%.
My car does not feel sluggish (except for when I read the odometer!!).
I also get poor M P G .

How many M P G do you get? I get 10-20 (depends on how hevy my right
foot is).
Mike

Gas mileage isn't an issue if you have NO oil pressure - your engine will seize and you won't use ANY gas!

Seriously, though, low oil pressure combined with lousy gas mileage might mean that your engine is just about done. Check to see if there is excessive oil at the air cleaner end of the crankcase breather tube (it connects to the valve cover). Also check for smoke blowing back through the valve cover with the engine running (pull the tube off the valve cover to check this). There should be a slight vacuum at the crankcase breather. Lay a piece of paper over it to check this. If the paper blows off and/or there is smoke coming out, you have excessive blowby due to worn piston rings.

Another reason you may have low oil pressure is a sticking relief valve on the oil pump. This may be causing your gauge flutter. If your engine is worn the way your symptoms seem to describe, chances are there is sludge buildup around the valve, causing it to hang up. Sorry I can't give you better news. But it looks like a power upgrade may be in your future!

Dan

did you guys know that most engines can idle for years with only 5 to 7 psi of oil pressure.

What does the mechanical gauge connect to, and if it reads low pressure, could you elaborate on chasing it down.

thanks,
mike

I cant look at my car right now because it is coverd with ICE and SNOW :banghead:

previously inspected, I have seen exsessive oil in the air cleaner end of the crankcase breather tube. I also think my car suffers major blowby
(when I start the car... dark smoke).

After reading what you have typed, I am beginning to wonder if the power uprade I need comes in a large crate (intake-oilpan).

On the other hand, I have about 185,000 miles!

Thanks for the insite.

Mike

no because you dont want preassure really you want volume in a sense. an oil pump does not create preassure it creates volume. the size of the oil gallerys and the bearing clearences mostly decide oil pressure. if pressure is too high it can spray the babbot off of the bearings. which is compleatly unrelated to the topic but i thought id answer 91. the mechanical gauge connects directly into the block somewhere. it usually has NPT(national pipe thread) so make sure if you buy any adapters that they are npt. im not positive on the motor that your car has but if it is a RS with a 305 its prolly right under neath the distributor near the firewall. in the dead center of the motor. if it is the V6 its prolly near the oil filter like he said. you really just need any spot that you can thread directly into an oil gallery like some sort of plug in the head or block. remember tho oil gallerys are small any large plugs will prolly be water jackets.

ok,

took the car into the mechanic, they checked it out mumbled something abaout a switch, replaced it...(i have a feeling that this did nothing) however...interestingly they checked the oil and it was very dirty, (we got it changed about a month ago) they changed it again and replaced the filter....i now am getting significantly more pressure for longer but after driving it for a while it resorted back to going to 0 pressure when it stopped and then once i begin accelerating it rises again.....to me it sounds as if the lines are dirty and a few more changes might clean it out? any ideas?

shawn

1991,

Today I am expecting good wether. If the snow melts off my car
I plan to begin replacing my oil pressure switch, changing the oil and filter, (and replacing the heater core because its busted).I hope this makes a difference.

Ill get back to you.

Mike

If you're lucky, the relief valve is sticking open and changing the oil cleaned it enough for it to close a little more. Try dumping some engine flush in before you change the oil again. Pour the flush in, run the engine for 10-15 mins, then change the oil. Don't rev the engine or drive the car with the flush in the crankcase!

Dan

Replaced oil pressure switch, it has worked well for the last few days...
:lol2: