astra oil change: sheered plug?

Stephen wrote:

First buy a new plug, check that it is actually t40 (it might be 45 ! )  I
can't remember offhand which size it is.  Assuming you are right and it is a
40 and the teeth in the hole have torn off, then you need to grip the outer
edge to undo it, IIRC the plug is raised slightly from the sump and you
should be able to get a pair of stilsons on to undo it (or big mole grips)
Best not to hammer at it as the sump is thin steel.  Other methods to undo
it would include welding something to it in order to turn it.

On 07/08/2012 22:45, Mrcheerful wrote:


Agreed. Although Stillsons have asymmetric teeth, theoretically better
than the Mole symmetric ones, I usually find Moles more effective
especially if you are gripping over a narrow band rather than a full
"pipe". The trick is to tighten up the screw until you can only *just*
get the Moles to close. At this point you should have deformed the
sacrificial part so that the Mole teeth have a very positive engagement.
You might even get away without buying a new plug.

On Wed, 08 Aug 2012 21:54:04 +0100, newshound


Thanks. I could have refitted the old plug but I would have had to use
mole grips each time I wanted to change the oil, so I thought it would
be less hassle to buy a new plug.

I don't have any stilsons. I must admit I've never really known what
they are for. They always seem to be sold in the plumbing section of
stores, so I thought they were for compression fittings only I learnt
from lurking in the diy group that you should use spanners with flat
surfaces for these, not the teeth of a stilson. I thought they were
for gripping cast iron pipes or something? Are they useful for
automotive use? perhaps I should get a cheap set just in case?

Thanks,
Stephen.

On 12/08/2012 18:09, Stephen wrote:

Almost correct, stillsons are basically designed for gripping iron or
steel pipe, but grey cast iron (like drainpipe) wouldn't normally be a
good idea. I havn't needed to use mine for years (I think I bought them
when I had to dismantle a gravity hot water system).

You can use them on compression fittings (especially those ones with six
ribs rather than a proper hexagon) once they have got rounded off. More
for disassembly than assembly!

On Sun, 12 Aug 2012 20:37:39 +0100, newshound


I've only ever seen copper pipe in domestic situations, so I don't
think I would ever need to grip iron pipes.

Is it that these iron pipes had threads cut into them and so there was
no separate fitting and so you had to turn the pipe?


Perhaps I should stick with my mole wrenches as it sounds as though
they do more or less the same thing?

wrote:


That's the norm for steel water or gas pipes.

On Tue, 7 Aug 2012 22:45:02 +0100, "Mrcheerful"


Thank you. I have heard it suggested that you should replace the plug
whenever you do an oil change on any make/model of car, but I must
confess, I never have. Perhaps changing the washer is a good idea but
if the plug is sound, I've never seen the point of changing it but
that was until now.

I've never seen an oil plug with torx fitting before. *If* they are
susceptible to having the teeth disintegrate, then I think replacing
the plug annually is a good idea. However, I think that perhaps the
torx failed due to abuse rather than age? The dealer said perhaps the
previous owner used an Allen key rather than  torx! I wondered whether
the teeth would snap off if over tightened with the proper Torx bit?

Whatever caused it, your suggestion of using mole grips was a great
idea that I should have thought of but hadn't! They worked perfectly.
I used a torque wrench to tighten the new one. Actually my 3/8" torque
wrench doesn't go as low as the 10Nm recommended by Haynes, so it is
slightly tighter than it should be, but only just.

Thanks for the warning about not hammering the sump. I hadn't realised
the sump was so thin and easily damaged.

The welding something on is a good idea but I don't have a welder and
have never welded. Perhaps I should buy a cheap one from aldi next
time they are on sale and learn how to do it? It must be a useful
skill for so many other jobs too.

I've noticed my ramps are rusting. I'll have to wire brush and repaint
them one day. OTOH it is only cosmetic, so perhaps I should not be so
fussy and save myself a job. I can't see how the water got under the
paint to start them rusting as they are kept in the garage and only
brought out once a year in the summer to do an oil change.

Haynes suggests changing the oil every 9000 miles or 6 months. Hidden
away it says this is half of the manufacturer's interval. Wasn't there
something on here before saying that changing too often was bad? I
think I will stick with 18k or 12 months.

Curiously the Haynes book does not mention T40 bits on the sump and
claims that it is a normal hex bolt and shows a photo of a hex bolt
too. I've noticed it is wrong about the cabin filter as well: it says
remove three screws but I found two torx bolts securing mine.

The pollen filter seemed to have something patches of something
looking like orange mould on the inside. I think there was sometimes a
damp smell; I wonder if that was why? Does this normally happen or
does it show something to look into? Surely the filter would have to
be getting wet for mould to grow and it should not be getting damp,
should it?

Thanks again,
Stephen.

Stephen wrote:

Stilsons are useful for trying to move anything of any shape whether or not
it has flats, so they are a useful thing, but I only very rarely use them on
a car.

Haynes are frequently completely and dangerously wrong about things, which
is why they are known as the Haynes Book of Lies.

I cannot remember ever seeing mould grow on a pollen filter, they should be
changed every other year (as a general guide)

Obviously you should check that you have the exact right Torx bit for the
new plug, older vauxhalls generally had a hex head sump plug.  Changing the
washer is always a good idea, on some cars the plug and washer are one piece
and should be changed every time (although rarely are)  Torx splines do not
tend to strip out, so previous abuse is likely.

Unless you are really interested and have some plans, then buying a welder
is unlikely to be very much help to you.

Yearly oil changes are fine for most people unless you do lots of miles.
Using the genuine oil and filter is a very good idea.

On Sun, 12 Aug 2012 20:38:21 +0100, "Mrcheerful"


I've just replied to newshound that it sounds as if mole grips do the
same thing, so perhaps I have no need to buy Stilsons as well?


Perhaps they copied and pasted the text from a book of an earlier
model? But of course that is no excuse and it should have been checked
before publishing.


I don't know that it was for sure but it was on the "wrong" side of
teh filter, i.e. not the side that had collected the dust and dirt and
it did look a bit like the mould you get on old bread, although orange
rather than green.

The filter did not seem wet to the touch. I've never seen mould on one
either but then I've only ever changed one a year on my own car, so I
have a lot less experience than you!


It is definitely T40. T45 will not fit and I checked with the dealer
too. It has an integral rubber washer, or at least the dealer-sourced
one does. Halfords told me they could order a plug and washer but the
washer costs £10 more than the plug! The dealer one was only £4.


Yes, I checked the oil spec against the handbook.

On 12/08/2012 18:04, Stephen wrote:

Probably not as useful as you might think. You'll need proper
instruction and a lot of practice to get competent, and you may only
discover bad welds when they fail. Silver soldering is a lot easier.

On Sun, 12 Aug 2012 20:43:26 +0100, newshound


I realise it will take a lot of practice and I don't intend to be
doing body repairs nor anything structural. I just thought the "weld
something on to a broken bolt" trick might rescue me on other
occasions too. Would solder be strong enough for this? I didn't think
it would.

That's why I thought a budget model from Aldi, so that I didn't loose
much if I was no good. I did look into classes once but they all
seemed to be vocational rather than hobby classes, so were very
expensive.

On 14/08/2012 19:58, Stephen wrote:

Soft solder wouldn't be strong enough, and you couldn't use silver
solder on an in-situ bolt (although you could weld to it, at some risk).

But if you got the plug out, you could (for example) drill out the torx
socket to a suitable diameter, get an ordinary bolt and cut off the head
leaving a bit of the shank, then silver solder that to the plug, giving
you a new and accessible hexagon for a conventional spanner or socket.
Silver soldering is often colloquially known as brazing, although
strictly speaking that's another process. There's a bit of skill to it,
but it's rather like soldering except at bright red heat. Plenty of info
and supplies of suitable rod and flux on the net. Flux is absolutely
essential. An ordinary plumbers propane torch is plenty hot enough, but
you may need to insulate the thing you are trying to heat to get up to
the right temperature. You can do this with proper firebrick, with the
lightweight vermiculite bricks used to line some types of stove, or at a
pinch with ordinary domestic bricks. The secret of a strong joint is to
have a relatively small gap between the parts, relying on surface
tension to draw the solder into the gap. This is why I was suggesting
making a "spigot" arrangement using a bolt. Alternatively you could just
file the plug flat, and solder an ordinary hex nut to it, but it would
not be as strong.

I know this would all be pointless where you can buy a new plug for a
few pounds, but if it were a vintage vehicle with a completely obscure
thread, or some more complacted part it might be worth it.