Oil fill level

[GTRS Fiero]

If measuring on the dipstick, how much oil do you put in your Fiero?

[Fierofool]

Supposedly, when using the Fiero 2.8 dipstick in a 3.4 engine swap, the reading will be incorrect.  That's why Rodney made the shim to go on the oil dipstick. 

Personally, I don't see that, especially when the Fiero oil pan is used.  It has the same relation to the block.  The hole in the block of the 3.4 where the dipstick tube inserts would have to be located higher or lower in order to affect the reading.  I can see the possibility of the 3.4 pan being a little different and therefore a need for a recalibration of the dipstick. 

Even though the recommended oil capacity is 4.5 quarts, I've always put in a full 5 quarts.  I've never noticed any ill effects of this, including the possibility that the engine will blow the excess oil out. 

I will go out today and pull the dipstick from the 3.4 and insert it into the 2.8 to see how oil levels compare. 

[Fierofool]

I just checked the 3.4 against the 3.1 and swapped dipsticks to each engine.  Of course, both dipsticks are for a 2.8, and they both indicated the same oil level for each engine.  Both engines were equal, so I don't really see a need for Rodney's dipstick spacer shim. 

The only way to tell the correct oil level for your engine is to change oil and filter, add 4.5 quarts and start the engine.  Then after it's set for 5 to 10 minutes, check the level.  My 3.1 has just had a fresh oil change, and my 3.4 oil level agrees with it. 

[GTRS Fiero]

Supposedly, when using the Fiero 2.8 dipstick in a 3.4 engine swap, the reading will be incorrect.  That's why Rodney made the shim to go on the oil dipstick. 

Personally, I don't see that, especially when the Fiero oil pan is used.  It has the same relation to the block.  The hole in the block of the 3.4 where the dipstick tube inserts would have to be located higher or lower in order to affect the reading.  I can see the possibility of the 3.4 pan being a little different and therefore a need for a recalibration of the dipstick. 

Even though the recommended oil capacity is 4.5 quarts, I've always put in a full 5 quarts.  I've never noticed any ill effects of this, including the possibility that the engine will blow the excess oil out. 

I will go out today and pull the dipstick from the 3.4 and insert it into the 2.8 to see how oil levels compare.

That's a good test.  I guess mine has 5 quarts.

[GTRS Fiero]

I just checked the 3.4 against the 3.1 and swapped dipsticks to each engine.  Of course, both dipsticks are for a 2.8, and they both indicated the same oil level for each engine.  Both engines were equal, so I don't really see a need for Rodney's dipstick spacer shim. 

The only way to tell the correct oil level for your engine is to change oil and filter, add 4.5 quarts and start the engine.  Then after it's set for 5 to 10 minutes, check the level.  My 3.1 has just had a fresh oil change, and my 3.4 oil level agrees with it.

Where does the oil level indicate, on the dipstick?

[Fierofool]

The 86 and 87 are right on the full mark.  However, in hind sight, I'm not sure if I put 4.5 or 5 quarts into the 86, and the 87 may be low.  I scribed a mark on the 87 dipstick to indicate 5 quarts, and it was down to the OEM mark.  It's probably about a half quart low at 4.5 quarts.  So, I think both 2.8, 3.1, and 3.4 all register at the full mark at 4.5 quarts. 

[GTRS Fiero]

So, people are telling me that the oil should be halfway between the add and full marks.  I've never heard of such a thing.  I want my battery full, my coolant full, and my fuel tank full.  Why would I want to be low on oil?

[Fierofool]

Yeah, I guess the best way to find out where the level should be is to do the oil change like I said.  Add 4.5 quarts and see where it indicates.  I'm not ready for a change on the 87, yet. 

[GTRS Fiero]

I have the spacer.  It has 5 quarts of oil, and is on the full line.  When I swapped to the 3.4, I ended up with a different dipstick (3.4).

In general, isn't anything below the full line considered low?

[Roger]

So, people are telling me that the oil should be halfway between the add and full marks.  I've never heard of such a thing.  I want my battery full, my coolant full, and my fuel tank full.  Why would I want to be low on oil?

You're right. Whoever told you that was bonkers. A 3.4 with a new filter should take 5 quarts.

[GTRS Fiero]

May I quote the "bonkers" part?

[Fierofool]

I just finished an oil and filter change on the 3.4 engine.  It uses the Fiero dipstick and tube and the 3.4 oil pan.  I put about a half pint of oil into the filter before installing it, then put the gallon of oil into the engine. 

I did not start the engine at this point and after allowing time for the oil to drain to the pan, I checked and the level was right at the factory full mark indicated on the dipstick.  So, I started the engine and let it run for about a minute and shut it down.  I gave it about 5 minutes for the oil to drain back to the pan.  When I checked the level, it was somewhere about halfway between the full and low marks.  This is considered a half quart low.  I then added another half quart of oil and giving another minute for it to drain to the pan, I checked again.  It was at the full mark. 

Engines are considered to still have enough oil to safely run in normal conditions when they are at the low mark.  It's a built-in safety factor.  That was part of the problem with the 84 Duke.  It came from the factory with its safety margin already gone, so as it began to leak oil and the level dropped below that safety margin, the engines failed. 

[TopNotch]

On my 88 duke, with the in-pan filter, there's nothing you can do but add the recommended amount of oil when you change it. The owner's manual says it takes 4 quarts of oil, so that's what I add. But with that much oil in it, the dipstick indicates about a quart above the full mark, even after running it and waiting. So I can only guess that it has the wrong dipstick or dipstick tube.
So later, if I need to add oil, I add to where it indicates after an oil change.

[Fierofool]

I searxhed for 94 Firebird fluid capacities and everything that comes up for 93-95 Camaro or Firebird 3.4 lists it as engine code S.

This from a forum:
Re: how much oil in a 3.4l v6
ok put 4 in seems that the filter is on a angle i dint fill the filter up like i usually do and put 4 qaurts in . and it seems low on the dip stick when the car is off.looks like 1/2 qaurt low seems that its because the oil filter was empty so it take 4.5 qaurts to 5 qaurts of oil .

One capacities chart lists 4.5 quarts with a filter while another lists 5 with filter but has a footnote to check level after refill.  This from the search question:
https://www.amsoil.com/garagecore/VehicleLookupPrint.aspx?url2=1994+PONTIAC+FIREBIRD+S