Great writeup! I'm thinking about this myself but I saw your post on my phone and couldn't make the link work so I got to my computer. I've never traveled to the 'other end' of the dipstick tube so I was curious what was involved. I took the liberty of C&P ing the text here in the body of the thread. Extracting the photos from the PDF would have been actual work
so I skipped them. Feel free to edit them in if you want. I do like the PDF as a 'printer friendly' option though.
Text from CharlesE's nice dipstick FAQ:
Oil Dipstick Changeout
Why?
The factory dipstick has two annoyances:
1. The handle is plastic molded onto the steel dipstick, and tends to break off easily.
2. The dipstick is black in the area where the oil level is read. This makes it difficult
to determine the oil level in dim light.
The replacement dipstick corrects both of these issues. It offers a formed steel handle
(with a plastic tube cover) and it has an aluminum end where the oil level readings are
taken. It’s also a Mazda factory dipstick (so there’s no worry about compatibility with
the engine), which was only used on California spec Miatas!
This task is of medium difficulty, mostly because of one nut that’s difficult to work on.
The car will also have to be on jackstands or a lift. You’ll need to be under the car for a
period of time, so safety becomes an issue. I don’t trust jackstands with me under them;
they’re typically made of cast metal which can fail suddenly. Consider also blocking the
car up with firewood, wheels and tires, anything that makes you comfortable working
under the car. Concrete blocks are not a good idea, since they can fail under an impact
load.
Suggestions:
1. Do this when you’re doing a coolant or heater hose change. – That will give you
more working room.
2. Consider removing the exhaust manifold heat shield (shiny aluminum part).
3. Consider tilting the car so that the drivers side is slightly higher than the
passenger side, so that the oil in the pan is less likely to leak out.
4. Clean the area you’ll be working in with Simple Green and water from a hose
stream. Do it twice!!
5. Verify that you have the new dipstick, the new dipstick tube, and a new Viton O-
ring. Insure that the new parts are clean.
6. Disconnect the battery, you’ll have to remove an electrical ground and replace it
during the course of the work.
You don’t NEED to remove the heater hoses or the heat shield, it just makes life a lot
easier. I didn’t remove the heater hoses and only removed the shield late in the project.
Heed my experience.
Equipment:
You’ll need a 10mm gearwrench or something similar, jackstands (at a minimum), a
good handcleaner (Autozone Fast Orange or similar), thin mechanics gloves (there are
many sharp edges, so medical latex type gloves are likely too thin) and some patience.
A torque wrench would also be useful, if you have one that’ll reach into this space.
Small is good.
Procedure:
Check the oil level on your existing oil dipstick. Either measure it or photograph it, so
that you can use it as a check when you install the new dipstick.
Assuming your draining the coolant, gently remove the radiator drain plug (it is rated for
10 inch pounds of torque – inch pounds not foot pounds! That’s almost no twisting force
at all. Take care not to strip this. Should you strip it, however, a temporary replacement
can be made using the metric bolts and Teflon tape found in any hardware store.
Drain the radiator and remove the heater hoses at both ends. Oh…..This is best done on a
cold engine, you’ll be working around a lot of otherwise hot metal. The factory hose
clamps are difficult to remove and replace, but reliable. You might want to consider
replacing them with worm gear type clamps such as T-Bolts or constant torque. Clean
the hoses thoroughly and twist them slightly to check for cracks. If these hoses fail,
you’re stranded. Replace them if you’re not sure they’re good. Oh….remove the
existing oil dipstick, and plug the dipstick tube with a bit of paper towel or cloth. This
will protect it from damage.
Once this is done, remove the sheet metal aluminum heat shield above the exhaust
manifold. If you have an FM intake, it’s necessary to remove one of the intake tubes in
this area. Since its held on by two hose clamps, not too much detail is necessary from
me. You should plug the intake ends (both of them) with clean rags or paper towels. It’s
held on by five 10mm bolts. You do not want to remove any bolts that go into red
painted metal. The right hand top bolt also holds a wire support for a hose.
Once the bolts are removed, the shield can be manipulated so that it can be removed by
tilting it upwards and towards the oil dip stick. It comes out with little to no force
required. Try not to bend it; it’s likely an expensive piece to replace.
Now that the heater hoses and the exhaust heat shield are removed, access to the dip stick
tube will be much easier. About half way down the dip stick tube is a metal bracket
which is holds the oil dipstick tube and an electrical ground which runs between the
chassis and the engine block. The ground wire looks like a woven flat strip of bare metal,
with ring connectors on each end. One end is readily accessible on the red painted metal
shelf. Unfortunately, that end need not be disturbed. The ground is there for a reason, if
it is in bad condition, it should be replaced – that isn’t likely, though.
On the side away from the engine (firewall side) is a 10 mm nut that holds the dip stick
tube and the electrical ground to the bracket. That nut and its bolt (actually a stud, since
its pressed into the bracket) are the only mechanical means of securing the dip stick tube
to the engine. The real work of this project is removing AND not dropping the nut into
the inner reaches of the chassis / engine. Should you drop it, and not be lucky enough to
have it fall through to the ground, you’ll likely need a magnet to remove it. Most parts
stores sell magnets on wands just for such purposes, for a few bucks.
Once you’ve removed the nut and moved the dipstick tube off the bracket bolt, you
should be able to pull the dipstick tube out of its socket. It’s only held in by an o-ring.
You’ll notice a lot of grime around the hole. It’s exposed to everything that splashes up,
and traps it on the flat surface. Way back on the first page, I recommended cleaning the
work area, this is why. You don’t want any of that STUFF getting into the oil pan and
engine internals. This procedure doesn’t cover engine replacement.
If yours is dirty, clean it with Simple Green and paper towels. Heck…clean anything
within reach!
The phrases ‘Assembly is the reverse of disassembly” comes to mind here. Thread the
new dip stick tube down through from the top, once you’ve installed the new o-ring on
the end of the tube. Set it into its seat. This would be much easier if you have a buddy to
work from up top, while you guide it into place.
Once it’s seated properly, reassemble the metal bracket, dip stick tube, electrical ground,
and the nut. Again, this is likely much easier to reach on the assembly line than in the
field. The workshop manual requires 75 to 95 inch-pounds or 6 to 8 foot-pounds. That’s
not much torque. Be gentle, this is your cars first dip stick replacement. Make it a good
experience. Also reinstall the exhaust manifold shield, again 75 to 95 inch-pounds.
Install the new dip stick, in the new tube. Remove it and compare the oil level to that of
the original dipstick. They should be the same or very close.
Reinstall the heater hoses. Replace the radiator drain, Remember it only requires 10 inch
pounds of torque. You’re dealing with plastic threads in a plastic radiator. Use a large
Philips screwdriver with two fingers, turned very lightly. The drain plug is easily and
inexpensively replaced; the radiator is expensive to replace. Fill the radiator with a mix
of distilled water and coolant. There are procedures in the FAQ’s to do this.
Replace the intake hose that you likely removed earlier. Remember to take out the plugs
you put into the plumbing ends.
Start the engine, check for both oil and coolant leaks. Place a newspaper under the car’s
engine to see if any fluids collect on the paper. If you have a boost gauge, check its
vacuum reading.
Take the car out for a test drive. After returning, again check for leaks and verify the
fluid levels are correct. If you’re wondering why so many checks for leaks and fluid
levels, its FUN to check the oil now. Smile.
You’re done.
