I have noticed that my car's oil pressure seems like it was dropping. When pressing the accelerator it rises between 40-80 lbs of pressure. At idle it was settle around 18-20 lbs of pressure. After I got off the highway I noticed in a matter of five minutes it was steadily dropping from 20 to near 0 lbs of pressure during idle. Of course when I press the accelerator it would go up but return to the red zone at idle. After I got home I noticed there was a small oil leak appearing under the battery terminal area. I haven't been able to jack up the car yet to take a greater look. Anybody know the best ways to approach this issue? I'm not the most mechanically inclined but I like to get my hands dirty from time to time.

[This message has been edited by Iron_Mark_2003 (edited 08-13-2010).]

If this is a new issue and both started at the same time, check the oil pressure switch. It is located near the battery above the A/C compressor on the V-6. Check around the base of it for leaks too. It is a three wire connector.

Check the line too, it may have a pin hole in it if rust is present.

[This message has been edited by Indiana_resto_guy (edited 07-06-2010).]

Is there any new noises coming from the engine? Ticking or knocking? If everything sounds normal you are probably ok but as mentioned above, verify that the oil pressure sender and gauge are working asap.

Charlie

Have you pulled the dipstick to see how much oil you have?

quote Originally posted by phonedawgz: Have you pulled the dipstick to see how much oil you have?

+1

quote Originally posted by phonedawgz: Have you pulled the dipstick to see how much oil you have?

Yes, and it is still near the full line.

good chance your sender is leaking if your getting it dripping from under the battery specifically, you shouldnt have any trouble seeing that oil pressure sender from the top next to the battery Check there if it looks dry then youll want to look into it further, best bet to avoid damage till you figure out for sure is to assume it really is low pressure.

Any chance you reciently changed to a thinner grade of oil?

quote Originally posted by phonedawgz: Any chance you reciently changed to a thinner grade of oil?

No.

I was looking at the sender today and it does not appear to be dry. Looks like she might be the culprit. Take a look.

Looks like mine did right before it really let loose. i would change it now before it really starts leaking.

Any handling advice when removing these things? I know you have to be careful as to not break the connector.


Edit: I'll probably purchase my sender through the Fierostore in order to have no risk of issues.

[This message has been edited by Iron_Mark_2003 (edited 07-15-2010).]

The nut ISN'T the big plastic thing. Its right below the base. Make sure you hold the line steady with a seperate wrench

quote Originally posted by phonedawgz: Its right below the base.

Do you mean the nut I have highlighted?



EDIT:Ah nevermind. I can tell from the picture of this sender below that this is the plastic part you were talking about. It's UNDER the base. I gotcha.

[This message has been edited by Iron_Mark_2003 (edited 07-15-2010).]

Is it easiest to remove the sender from under the car or from the top?

bump

The Fiero Store will usually give PFF members a 10% discount, (you have to ask) on most non-GM parts.

Change out the oil and filter with a heavier oil or use your stock grade and add some Lucas oil treatment, see if you can re-create the difficulties. (I use Lucas during hot summer months)

You can also purchase some untra-violet crankcase marking dye at the auto parts store, buy a cheap "party light" at the hardware store and you'll have no difficulties whatsoever in finding oil leaks.

Fiero gauges are nortorius for their inaccuracy, get a mechanical gauge on the engine, lets be certain of what we're dealing with.

Can anyone tell me what size the nut on the pressure sender unit is?

quote Originally posted by jetman: The Fiero Store will usually give PFF members a 10% discount, (you have to ask) on most non-GM parts.

No anymore - too many people got wind of this and were abusing it.

------------------
My World of Wheels Winners (Click on links below)

3.4L Supercharged 87 GT and Super Duty 4 Indy #163

I think it's 9/16... just a try. Good luck, remember keep a good hold on the tube below the oil pressure sending unit, as they can cause a nasty leak!

quote Originally posted by jetman: The Fiero Store will usually give PFF members a 10% discount, (you have to ask) on most non-GM parts. Change out the oil and filter with a heavier oil or use your stock grade and add some Lucas oil treatment, see if you can re-create the difficulties. (I use Lucas during hot summer months) You can also purchase some untra-violet crankcase marking dye at the auto parts store, buy a cheap "party light" at the hardware store and you'll have no difficulties whatsoever in finding oil leaks. Fiero gauges are nortorius for their inaccuracy, get a mechanical gauge on the engine, lets be certain of what we're dealing with.

dood, Lucas oil treatment is bad, it destroys engines over time by destroying the anti-foaming agents in oil. the gears in your oil pump airate the oil and turn it frothy:

http://www.bobistheoilguy.c...ages/lucas/lucas.htm

Well I attempted trying to loosen the nut on the pressure sender for the second time. Hoping this time having some proper tools would come in handy. That nut is a beast. It won't budge. I was wondering if it safe to put some pb blast or wd40 on it to loosen it up?

quote Originally posted by fierosound: No anymore - too many people got wind of this and were abusing it.

i find that hard to believe, since just about ALL fiero owners have used this forum at one time or another...i don't see how that is abuse, that's just good business...

So, would it be okay to spray some PB Blast on the nut?

HELP!!! I cannot get that nut to loosen for anything. I am out there trying to turn it 'til the point that I'm shaking. Not to mention it's a pain in the ass trying to hold vice grips on one hand, and turn the nut on the other hand. I've removed the battery for space, but to no avail. That NUT will not loosen! I know that I've flexed the line underneath it back and forth a bit. I'm at wits end with it. I'm thinking about just ripping the old pressure sending unit off and use a cutting wheel on a dremel to cut it all the way down to just a visible nut and have a good at it from there. Please help...


Oh and the jerk who put the new engine in this car didn't bother using the retaining bolt on sending unit tube, so I don't know if I'm boned or not. I'm so frustrated right now. It sucks when I need this car for school.

[This message has been edited by Iron_Mark_2003 (edited 08-11-2010).]

Don't know what to tell you. Use some PB Blaster or similar and get a bigger hammer? Make sure you are loosening it?

I installed the new switch and started everything up. It sat at around 70 lbs of pressure, than hit about 60 and kept for awhile. Still idling, it steadily found its way back down near 20 lbs of pressure. I decided to drive it around half a block. Like before when I hit the accelerator, the pressure jumps up to around 40 lbs of pressure, but when you're just cruising or in a coast it falls back down steadily. I pulled into the garage where it steadily went down until it found itself sitting right at the line before the red zone. It didn't fall into the red. At least I didn't let it yet, but it seemed to halt there for the time being.

What am I to do at this point now?

[This message has been edited by Iron_Mark_2003 (edited 08-13-2010).]

One of the things you can do to mask the problem is run thicker oil. If you're using 5W30 try 10w30. The actual thickness of the oil is the first number. If you're running 10w30 you can try just straight 30 weight oil. However you don't want to be running 30 weight oil in the winter. The engine will crank over so slow that it won't start.

How long ago was the engine installed? How many miles were on the used engine when it was installed? Is the oil pressure getting worse or staying the same?

[This message has been edited by phonedawgz (edited 08-13-2010).]

quote Originally posted by phonedawgz: One of the things you can do to mask the problem is run thicker oil. If you're using 5W30 try 10w30. The actual thickness of the oil is the first number. If you're running 10w30 you can try just straight 30 weight oil. However you don't want to be running 30 weight oil in the winter. The engine will crank over so slow that it won't start. How long ago was the engine installed? How many miles were on the used engine when it was installed? Is the oil pressure getting worse or staying the same?

I'm going to try and do an oil change on it running 10w30.


From what I was told about the car when I bought it from the previous owner (who INSTALLED the new motor) was that the engine was put in about 2 years ago. I was told it's a brand new motor and has accumulated probably close to 3,000 miles on it (my mileage and his included). The oil pressure was steadily getting worse, but one day it just seemed to plummet straight down to the red zone in pressure. Now after the new sending unit was installed it seems to be about the same. I let it sit in the garage idling and while it didn't seem to fall flat into the red zone it was sitting at the line right before it (I'm not sure how many lbs of pressure it translates to).

I haven't changed the oil in a good while, mostly because I haven't been trying to run the car a whole lot except for times that me and my wife can't make it on just one vehicle. When I pull out the dipstick, the oil still looks very new to me. It's not real sludgy or black. It shows rather clear, almost like a new bottle of oil. I don't know if that could be a tell-tale sign of anything. Could there be some water in the oil, causing it to have a diluted look?

[This message has been edited by Iron_Mark_2003 (edited 08-13-2010).]

That doesn't sound like you want to just run thicker oil then. You want to instead fix the spun bearing.

quote Originally posted by phonedawgz: That doesn't sound like you want to just run thicker oil then. You want to instead fix the spun bearing.

Wouldn't have one clue how to go about doing that.

quote Originally posted by phonedawgz: The actual thickness of the oil is the first number.

no, the first number is the cold viscosity. the second number is the viscosity at operating temperature. 10W30 and 0W30 have the same viscosity at operating temperature. 0W30 is thinner and flows better which offers better protection when cold (and "cold" means ambient temperature). if he wanted to run a thicker oil, he would have to find a xW40 or xW50 oil. however, if he's got at least 10psi per thousand rpm, more pressure just means less flow. less flow is a bad thing, since oil not only lubricates the bearings, but it cools them as well. more flow= cooler bearings.

what are the oil pressure specs? i haven't owned a fiero in years so i don't remember any of it anymore, but on my 3SGTE the idle oil pressure spec is as low as 3psi. beyond that, as long as you have at least 10psi/1000rpm you should be ok. try connecting a real pressure gauge to the oil system and verify that the gauge is reading correctly.

Low oil pressure is a serious problem that is not easy to fix. The more it sits at idle with low pressure the worse the wear on the engine, and the worse the pressure will get. You just may have a bad oil pump, but even so with pressure that low you now have bearing issues. The bearing clearances will get larger and larger and the pressure lower and lower.

quote Originally posted by Iron_Mark_2003: I'm going to try and do an oil change on it running 10w30. From what I was told about the car when I bought it from the previous owner (who INSTALLED the new motor) was that the engine was put in about 2 years ago. I was told it's a brand new motor and has accumulated probably close to 3,000 miles on it (my mileage and his included). The oil pressure was steadily getting worse, but one day it just seemed to plummet straight down to the red zone in pressure. Now after the new sending unit was installed it seems to be about the same. I let it sit in the garage idling and while it didn't seem to fall flat into the red zone it was sitting at the line right before it (I'm not sure how many lbs of pressure it translates to). I haven't changed the oil in a good while, mostly because I haven't been trying to run the car a whole lot except for times that me and my wife can't make it on just one vehicle. When I pull out the dipstick, the oil still looks very new to me. It's not real sludgy or black. It shows rather clear, almost like a new bottle of oil. I don't know if that could be a tell-tale sign of anything. Could there be some water in the oil, causing it to have a diluted look?

if your problem is low pressure when the vehicle is at full operating temperature, then 10w-30 wont help. you will need a 10w40 or heavier oil. at full operating tempurature, the 10w30 has the same weight as a 5w30, which is 30 weight try 20w-50 if you want a significant oil pressure increase that you will notice...

a hard cranking engine could be a starter going bad, starters can sometimes be sensitive to temperature changes, especially when they start to go bad. it could also just be a weak battery... as far as a spun bearing, didn't you say the engine was recently rebuilt? if it was, eliminate the cheap fixes first before you go dropping the oil pan ...

Iron_Mark,
If I lived closer to you, I'd tell you to purchase a few parts, then we'd spend about two evenings fixing the problem. As it is, I live in Northern Minnesota. Here is my "two cents" of advice, if you can get help from a friend who is mechanically inclined:
I've done this to three different cars, two of them Fieros, all with great results. In fact, one of them belongs to Yellow87FieroGT, my oldest son, who continues to drive his car to and from the Detroit area (about 780 miles one way) when he comes home. It is his daily driver and had the same problem you are describing. It now makes about 50 to 55 psi of oil pressure hot-idle and about 80 (or more) on a cold start while running 5w-30 Mobile 1. Hot pressure at 3500 rpm is aroune 75 psi. This car's longevity has been greatly extended, and it already had over 200 miles on it! This procedure assumes that your crankshaft is not damaged beyond normal wear!
Parts to purchase: 1 standard rod bearing set (assuming your engine hasn't been rebuilt before). (fiero store)
1 standard main bearing set ( " "). (fiero store)
1 high volume oil pump (fiero store)
1 oil pan gasket & silicone gasket compound.
1 large tube of Lubriplate engine assembly lubricant.
Total cost is under $200
The original fiero oil pump has an aluminum body, which wears poorly over time, causing oil to leak around the gears when it warms up. The high volume pump that the Fero Store sells is made of steel, and is designed to move more oil anyway.
You'll need to do the following:
1. Drop the exhaust system.
2. Remove the starter.
3. Support the front of the engine and remove the front motor mount
4. Remove the pan (check for shrapnel in the bottom of the pan...this can be a MAJOR clue about what's been going on in there).
5. Remove the old oil pump.
6. Remove the spark plugs.
7. Put a wrench on the damper pulley nut so that you can gently turn the engine.
8. Change the rod bearings one at a time: Remove the rod bearing cap. Push the piston up in the bore enough to remove the top half of the bearing. Be very careful not to
scratch any of the crank bearing surfaces while doing this. While you have the old bearings out, it is interesting to set them on a piece of glass next to the new bearings.
You will probably be able to see or feel the thickness of the new bearing compared to the old. Install the new bearing, using plenty of Lubriplate on the face of the bearing.
Install the rod bearing cap and torque to 40 ft/lbs.(check spec). Repeat for all 6 cylinders. Make crank still turns freely after each bearing is installed.
9. Loosen the main bearing caps JUST ENOUGH TO REMOVE THE TORQUE. Now remove the rear main cap. The lower half of the bearing will come off with it.
Removing the upper half of the bearing requires a flat brass drift, a very light hammer to tap the end of the bearing with, and another person to gently turn the crank in the
the direction that you are trying the roll the bearing out. Once you have removed it, do a "stare and compare" inspection of the old vs. the new bearing. Now use
Lubriplate on BOTH SIDES of the new bearing and start rolling it back in, in just the opposite way that you took the old one out. Place the bottom bearing half into the cap
with Lubriplate on the bearing face only. Install the cap bolts a little more the finger tight.
10. Roll the other mains out and back in the the same manner, one at a time, working toward the front of your engine. USE PATIENCE and CAUTION so you don't mar up
the crank. When you have them all in, torque the mains to spec. I think it is 75 ft/lbs (check spec). Double check the torque on all rod and main bearning nuts. Again, make sure the crank turns freely bearings are torqued. Don't force anything!
11. Re-install the oil pan, using a thin coat of gasket compound on both sides of the gasket. Make sure all the flanges are absolutely clean and you won't have any problems
with leaks.
12. Re-install the front motor mount, starter, re-hang the exhaust, install the spark plugs and wires in proper order.
13. Change the oil filter and put in new oil.
14. Connect battery, start the engine and let it idle, keeping a close eye on the oil pressure and listen for any unusual noises. The engine should run more quietly and
somewhat cooler than it did before.

Now go take a shower and get all that nasty grease and oil off of you!! (I didn't say this was a clean job).

The point is, the Fiero is a great car. You can add a lot of life to it with a couple of evenings of work ( a weekend or more if you take your time) and under $200.
You will miss it if you sell it.

I hope you can find someone with the tools and skill to help you with this . . . Good Luck!
~~Dan

------------------
Gold '87 GT, Black '87 GT, Black '88 Mera, 64 Stingray coupe, '01 Corvette coupe, '03 Corvette coupe & caretaker of son's Yellow '87 GT, & Other son's Red '86 GT,
General tinkerer and doer of mechanical deeds

Just a quick update for all those who posted what they thought. I bought the car from Mark verified oil pressure with manual oil tester screwed in block car has great pressure. The culprit was found to be a bad oil pressure gauge and some wiring to the sender that the previous owner before him did when they installed the new 2.8. No bearing or pump issues were found. Just an update for all those who helped him so they know the problem is fixed