I'm not certain if the Fiero has an oil cooler already, but I don't think it does.

By adding one, do you think it would help with my low oil pressure at idle after the engine is warm? I know that it is a common issue and that most don't worry about it, but would it help?

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1986 SE V6 Auto. 114K miles.
1995 F-150 4.9l Straight 6, Port and polished head, oversize valves, mild cam.

It would have the same effect as running thicker oil would. Larry

quote Originally posted by trotterlg: It would have the same effect as running thicker oil would. Larry

I already run thicker oil, but the problem persists.

quote Originally posted by BlackEmrald: I'm not certain if the Fiero has an oil cooler already, but I don't think it does. By adding one, do you think it would help with my low oil pressure at idle after the engine is warm? I know that it is a common issue and that most don't worry about it, but would it help?

it would help if you havehot-running issues or are burning oil...

if you have low pressure, test it with an aftermarket add-on gauge as the stock fiero gauge and sender may be off after a could decades of useage.

if it still reads low (fully warmed up at operating temp should be about 40-50 psi) then you either have a worn oil pump, a blockage, or a gremlin (not the fuzzy kind named gizmo)

hope you can resolve it.

as for putting an oil cooler on a fiero - it can't hurt anything as long as you have a bypass (for if/when the cooler gets blocked off..)

quote Originally posted by BlackEmrald: I'm not certain if the Fiero has an oil cooler already, but I don't think it does. By adding one, do you think it would help with my low oil pressure at idle after the engine is warm? I know that it is a common issue and that most don't worry about it, but would it help?

do you really have a low oil pressure problem? Hooked up a mechanical gauge?

No, I haven't checked it with a real gauge. Its not a big enough issue for for me. The car runs great, so I haven't seriously spent any time tyring to come up with a solution.

Accroding to the dummy guage, once I reach op. Temp, while the car is idling the low oil light comes on.

quote Originally posted by BlackEmrald: I'm not certain if the Fiero has an oil cooler already, but I don't think it does. By adding one, do you think it would help with my low oil pressure at idle after the engine is warm? I know that it is a common issue and that most don't worry about it, but would it help?

NO, it won't help. It will not hurt, but it will not help. You are wanting to change the viscosity of the oil by making it cold. The viscosity change you could get by cooling the oil a few degrees would be insignificant. The general issue with low oil preasure is loose bearings, if you want to change something, address the problem. Many engines run just fine with minimal idle oil preasure. Not that it is desired, but it is tolerable. I remember a few years back when GM was having us replace senders with ones that kicked the light at 3 PSI instead of 5 pai. The engines were kicking the light at idle otherwise (this was on new engines)

quote Originally posted by gtxbullet: if it still reads low (fully warmed up at operating temp should be about 40-50 psi)

i dont know of to many engines that run 40 -50 psi of oil pressure fully warmed up at idle more like 10-25 . never trust a factory gauge

quote Originally posted by BlackEmrald: No, I haven't checked it with a real gauge. Its not a big enough issue for for me. The car runs great, so I haven't seriously spent any time tyring to come up with a solution. Accroding to the dummy guage, once I reach op. Temp, while the car is idling the low oil light comes on.

Sounds like the sender....Have seen this several times....But I would check with a manual gauge to insure you dont kill the motor....

my 2.8 idle oil pressure when warm is 20 psi on a mechanical gauge. my gauge(with a new sender) in the car says 10 so you can see how much even a new sender can be off

quote Originally posted by BlackEmrald: Topic: Would Installing an Oil Cooler help with my low oil pressure?

Not unless the oil is running too hot. Is it? If so, why?

You need real data before you start jumping to solutions: As others have suggested, you need to confirm that your oil pressure is actually low ... using a known-good oil pressure gauge. Both the Fiero OP sender and gauge often have substantial errors. Second, you need to measure your actual oil temperature. Driving on the street the oil temperature should remain within about 20 degrees of the coolant temperature. An oil cooler is totally unnecessary in most cases, and a poorly-installed cooler (e.g. without an effective thermostat) can actually be detrimental to engine life.

What is your oil pressure at 2000 rpm? That will tell you more about the health of your engine than pressure at idle. Note also that running heavy-weight oil, as you've said you're already doing, can accelerate bearing failure in a worn engine rather than help.

[This message has been edited by Marvin McInnis (edited 03-11-2012).]

If you have a high mileage engine and your oil pressure light comes on during hot idle, then a high volume oil pump with the stock pressure regulator spring will likely fix the problem. I did that on the 3.1 in my Pontiac 6000, which had the same problem.

Once at operating temperature, at any RPM's above idle (1000-1500) the pressure is fine. I have have issues with my idle being high and surging in the past, and I assume I have a vacuum leak somewhere, but I haven't had access to a smoke machine to test it. My car is currently down for brakes, but that will be resolved soon.

The only reason I ask about an oil cooler is that A) I do not have this issue while the engine is "cold" B) I don't see how running an oil cooler could hurt anyways C) the light is really annoying.

I need to test the real pressure like has been said, But I don't have access to a mechanical gauge and I don't have the money to buy one. I was just hoping for quick fix for the future.

The suggestions that say to find out what the pressure really is are great suggestions. You can chase a lot of issues if you don’t really know what’s going on. If the pressure is truly low after the engine warms up it’s likely either bad main bearings or the pressure bypass. More than likely if the main bearings were bad you’d get some noise (not always but usually). The pressure bypass is in the pump and can get stuck in the bypass position. When the engine is cold and the oil is thick the bypass opens so the oil doesn’t have to go through the filter (it’s hard to go through when cold). When the oil heats up and thins out the bypass valve should close.
Keep in mind that an old plugged up filter can also force the bypass to stick open.
If you do wind up replacing the pump and high volume pump is not a bad idea however a high pressure pump can damage old bearings.
More than likely you’ll find that the pressure is OK and the sender isn’t.

What engine? 2.5 pressure sending units are prone to failure.

quote Originally posted by BlackEmrald: I don't have access to a mechanical gauge and I don't have the money to buy one. I was just hoping for quick fix for the future.

... but you have the money to buy an oil cooler and the necessary installation hardware? Not busting your chops, but a test gauge or new oil pressure sender is a lot cheaper than adding an oil cooler.

quote Originally posted by BlackEmrald: Once at operating temperature, at any RPM's above idle (1000-1500) the pressure is fine.

quote Originally posted by firejo24: More than likely you’ll find that the pressure is OK and the sender isn’t.

I agree.

quote Originally posted by firejo24: The pressure bypass is in the pump and can get stuck in the bypass position.

It can happen! I once worked on a 6-cylinder Jaguar engine that was shedding pieces of cotter pin from the connecting rod cap nuts, and those pieces were somehow managing to get through the oil pickup screen, passing through the oil pump, and lodging in the bypass valve. I was actually able to clear the bypass valve from outside the engine; replacing the cotter pins on all the connecting rod caps took a little longer.

[This message has been edited by Marvin McInnis (edited 03-12-2012).]

I agree with Marvin.

The first step to solving a problem is to (correctly) diagnose it. A mechanical oil pressure gauge will help you do that. If it turns out that your engine actually does have low oil pressure, then the solution would involve either a new set of engine bearings, or a higher volume oil pump.

An oil cooler will not significantly increase oil pressure. As a redneck might say, "yer barkin up the wrong tree!"

should lower the oil pressure a little to push the oil on a longer path thru the cooler

You might consider installing a high volume oil pump. I know someone makes such an item as I have one in my '87 turbocharged V-6.

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IF YOUR SURE your engine is not sludged up, you can go to a synthetic oil. I dont recommend Mobile One (high solvents) on a high mile engine, but there are many more. I use Castrol myself. Synthetic oils best attribute is its very resistant to engine heat. Most of my cars saw a pretty good jump in oil pressure switching. Mine are in a good condition before I switch. Several of my cars got as much as 20 pnd increase in hot oil pressure. Again IF your UNSURE of your engine condition inside DONT switch it or you can sprout leaks pretty quickly. Verify your oil pressure is actually low like already mentioned before you do anything.