Astra catastrophic loss of coolant

[Stephen]

Hello again,

We seem to be having terrible luck with our Astra. Tonight OH drove
home and said she heard a noise from under the bonnet. Wheni got home
I had a look and the hose that goes from the engine to the (I think it
is) the heater matrix has become detached from the engine. Reading the
Haynes book, I think it is actually the coolant pump.

It looks to me as though there is a small plastic stub (what's the
proper name for this?) that screws into the metal pump body and
protrudes into the hose, into which it is secured by a clip. This
small plastic stub has snapped and half remains in the pump body and
half remains in the hose.

I presume that I can drill the old one out and fit a new one but I do
not know what to ask for at the parts counter. Please can you tell me?

How could this happen. Nothing should have knocked it to snap it. Is
it just the effects of age and heat?

We do not know when the hose detached. My OH didn't notice any steam
or noises from under the bonnet. Should she have?

There is no coolant in any of the hoses I have checked. I think it has
all evaporated or been pumped out. How long can you drive an engine
without coolant before it fails? What would be the signs?

Presumably I fix the broken part, refill, and then let it idle and
hope for the best?

Thanks,
Stephen.

[Tim..]

"Stephen" <ste...@nowhere.com.invalid> wrote in message
news:0d9lv8lmas5qjjvhf...@4ax.com...

How long was the gauge in the red and the warning lamp on? How long is the
drive home and at what speed?

You *may* be okay. The coolant will have been pumped out probably within 30
seconds when the stub broke!

Tim..

[Chris Whelan]

On Thu, 01 Aug 2013 19:23:41 +0100, Stephen wrote:

[...]

> I presume that I can drill the old one out and fit a new one but I do
> not know what to ask for at the parts counter. Please can you tell me?

Something like this?

http://ebay.eu/1cv0tAm

> How could this happen. Nothing should have knocked it to snap it. Is it
> just the effects of age and heat?

Poor design?

> We do not know when the hose detached. My OH didn't notice any steam or
> noises from under the bonnet. Should she have?
>
> There is no coolant in any of the hoses I have checked. I think it has
> all evaporated or been pumped out. How long can you drive an engine
> without coolant before it fails? What would be the signs?

Seizure or death rattle. If it was running, it hasn't seized; if it
wasn't so noisy that it made your OH want to turn it off, it may well be
OK.

> Presumably I fix the broken part, refill, and then let it idle and hope
> for the best?

Yep. Google or ask here if there are any problems or special methods with
your particular engine (which you haven't mentioned yet) WRT avoiding air
locks.

Chris

--
Remove prejudice to reply.

[Chris Whelan]

On Thu, 01 Aug 2013 19:23:41 +0100, Stephen wrote:

[...]

> It looks to me as though there is a small plastic stub (what's the
> proper name for this?) that screws into the metal pump body and
> protrudes into the hose, into which it is secured by a clip. This small
> plastic stub has snapped and half remains in the pump body and half
> remains in the hose.
>
> I presume that I can drill the old one out and fit a new one but I do
> not know what to ask for at the parts counter. Please can you tell me?
>
> How could this happen. Nothing should have knocked it to snap it. Is it
> just the effects of age and heat?

Just found this (for a Corsa, but still relevant):

http://vauxhall.workshop-manuals.com/corsa-c/index.php?id=1949

HTH

[Mrcheerful]

Anything more than minor overheat is likely to bring on head gasket failure,
maybe immediate, maybe a year or two away. Really catastrophic over heat
takes the piston oil control rings or even compression rings first, followed
by major internal failure such as crankshaft shells.

The only thing you can do is get the bit from a dealer (just describe it),
fit it plus the right coolant and cross your fingers, no-one can accurately
tell you what, if any, damage has occurred.

[Chris Whelan]

On Fri, 02 Aug 2013 10:32:47 +0100, Mrcheerful wrote:

[...]

> The only thing you can do is get the bit from a dealer (just describe
> it)

Mr Google suggests that any dealer will know what the part is; it would
seem that failure of the plastic stubs is a known fault, and they are now
metal.

I've seen some reference to there being two sizes, so the OP needs to
measure diameters or take the old bits with him.

[Stephen]

On Fri, 2 Aug 2013 08:34:59 +0100, "Tim.." <flex...@hotmail.com>
wrote:

>How long was the gauge in the red and the warning lamp on?

There is no temperature gauge on this Astra (56 plate). F-I-L has an
08 Astra and that doesn't have a gauge either. A long time ago we
asked Vauxhall about this and they said many customers had complained
about not having a gauge, so whether that has been re-introduced or
will be introduced in newer model, I don't know.

I wonder how many drivers with a gauge actually look at it (like they
do with their mirrors!) Or whether many drivers would know what was a
good or bad level on the gauge?

Vauxhall did say that all models have a red light that comes on when
the engine is too hot. I can't remember the temperature now: 90C?
However, the driver tells me there was no red light.

>drive home and at what speed?

Problem is that she drove to a few places that morning, sow e don't
know when the pipe broke.

>You *may* be okay. The coolant will have been pumped out probably within 30
>seconds when the stub broke!

Let's hope it broke as she pulled onto the drive.

Thanks.
Stephen.

[Stephen]

On Fri, 02 Aug 2013 08:15:50 GMT, Chris Whelan
<cawh...@prejudicentlworld.com> wrote:

>Just found this (for a Corsa, but still relevant):
>
>http://vauxhall.workshop-manuals.com/corsa-c/index.php?id=1949
>
>HTH

Thank you. By coincidence I found this with google this morning. As
you said in your earlier reply, perhaps it is a design fault. That
page says that the plastic part is now replaced by a metal one.
Perhaps this is because too many plastic ones were snapping and they
decided a metal one would be more robust?

I hadn't realised it was for a corsa; do they have the same engine?
The pictures look just like the engine in the Astra.

I bought the replacement part from the dealer today. I didn't realise
I needed an O-ring (this was before I found that web page) so I may
have to go back tomorrow (I don't have a collection of O-rings in my
garage; perhaps I should buy some next time Aldi have an assortment
box on sale?)

I couldn't find my LH drill bits and then the thunder storm came, so
I will have to finish off tomorrow and use a RH bit if I can't find my
other ones.

How do I stop any bits falling into the pump? Run a vacuum next to the
drill, like at the dentist?! Do I need to worry about plastic swarf
falling in?

I don't have an M8 thread cutter, so I'm wondering whether I will need
to buy one of those or whether the original threads will be ok?

Thanks again,
Stephen.

[Adrian]

On Fri, 02 Aug 2013 21:01:09 +0100, Stephen wrote:

> I wonder how many drivers with a gauge actually look at it (like they do
> with their mirrors!) Or whether many drivers would know what was a good
> or bad level on the gauge?

I'd like to think that most drivers are capable of remembering the
position of a needle that's sat in roughly the same place AT ALL TIMES
THEY LOOK AT THE INSTRUMENT PANEL IN FRONT OF THEM, and capable of
registering the unusual proximity of that needle to the BIT MARKED RED...

<sigh>
Emphasis on "I'd like to think". I've always been a bit of an optimist. I
do appreciate that many of the people keeping the right front seat warm
have their heads anywhere but on operating the vehicle...

> Vauxhall did say that all models have a red light that comes on when the
> engine is too hot. I can't remember the temperature now: 90C?

It'll be a lot hotter than that. 90deg is just into low-speed fan
territory. I dunno about the Astra specifically, but I checked the spare
fan switch for one of ours the other day - the high speed kicks in at
105degC. So - north of there for "too hot".

> However, the driver tells me there was no red light.

Well, no, there wouldn't be. The sender for the light measures the temp
of the coolant it's submerged in. If a hose bursts, and there's no
coolant, then the sender isn't measuring the temp of anything...

If there was a temp gauge, then it'd have dived for "cold", not "hot".

I do like low coolant level lights. But, again, basic awareness would
have helped with a major failure like this one, rather than a minor leak
over time leading to low level. The fucking great big cloud of sweet-
smelling steam that filled their mirrors or enveloped the car could have
been a clue.

[Stephen]

On Fri, 02 Aug 2013 10:03:18 GMT, Chris Whelan
<cawh...@prejudicentlworld.com> wrote:

>
>Mr Google suggests that any dealer will know what the part is; it would
>seem that failure of the plastic stubs is a known fault, and they are now
>metal.

Sorry I replied to your other posts before reading this. You are
right, it seems to be a known fault and they are now metal, presumably
to prevent this.

>I've seen some reference to there being two sizes, so the OP needs to
>measure diameters or take the old bits with him.

I didn't know about the sizes. I gave the dealer the reg. and it looks
about the same as what is left of the old one.

[Stephen]

On Fri, 2 Aug 2013 10:32:47 +0100, "Mrcheerful"
<g.odon...@yahoo.co.uk> wrote:

>Anything more than minor overheat is likely to bring on head gasket failure,
>maybe immediate, maybe a year or two away.

I don't like the sound of the "may be a year or two away". In a way,
I'd rather any failure was immediately apparent, rather than find
myself break down in the middle of nowhere many months from now, when
all this is forgotten. But that's life I guess!

Thanks,
Stephen.

[Stephen]

On Fri, 02 Aug 2013 08:09:19 GMT, Chris Whelan
<cawh...@prejudicentlworld.com> wrote:

>Seizure or death rattle. If it was running, it hasn't seized; if it
>wasn't so noisy that it made your OH want to turn it off, it may well be
>OK.

Thanks,. Will refill with coolant and listen to what noise the engine
makes and report back next week.

[Peter Hill]

The overheating can warp the head, that reduces the head gasket
clamping. Then it takes time.

I had 3 hoses burst over 5 years on a 200SX, the head gasket failed a
year and 5000 miles after the last one.

Stick some K-seal in it if you think it may have an issue. Then you may
never notice.

If a modern (>1988) SI engine management system detects the engine is
overheating it will go very rich. Not much use to you but the Northstar
engine was supposed to be able to cross a desert without any coolant.
Diesels just run cold anyway.

--
Peter Hill
replace nospam with domain host name to reply

[Mrcheerful]

Almost invariably head gasket failure has been preceded by coolant loss
leading to overheat, questioning the owner always seems to bring up
something along the lines of the water pump went, the rad sprang a leak or
similar, somewhen in the past. However, in your case it may be that the
coolant loss was just at the end of the road coming home. Twice on my own
cars they have got home and had a leak spring outside the house! Once a top
hose exploded after a long fast run home, after I switched off. The other
was when my wife was turning round after driving home, standing at my gate I
saw the water suddenly start pouring out from what turned out to be a rotten
radiator (leaves trapped between main rad and air con rad, so invisible on
normal inspection)

[T i m]

On Fri, 02 Aug 2013 08:15:50 GMT, Chris Whelan
<cawh...@prejudicentlworld.com> wrote:


>Just found this (for a Corsa, but still relevant):
>
>http://vauxhall.workshop-manuals.com/corsa-c/index.php?id=1949
>

Interesting, especially as we have 3 model names off that list (Astra,
Corsa and Meriva) but luckily only one (the Meriva) is within the
model age range (04) but as it's a 1.6 so I don't think is affected by
this issue? (The 1.2 Corsa is an 01 and the 1.4 Astra a 92!). ;-)


Cheers, T i m

[T i m]

On Fri, 02 Aug 2013 21:51:12 +0100, Peter Hill
<peter....@skyshack.demon.co.uk> wrote:

<snip>

>
>If a modern (>1988) SI engine management system detects the engine is
>overheating it will go very rich. Not much use to you but the Northstar
>engine was supposed to be able to cross a desert without any coolant.
>Diesels just run cold anyway.

I (knowingly) drove my old Rover 218SD (Pug lump) home twice over 20
miles with no coolant and it did another 50 k miles (before the rust
and old age got the better of it and I scrapped it for 60 quid more
than I paid for it 7 years earlier).

Luckily they were easy trips and I was able to moderate the load to
keep the temperature under control but as you say, it wasn't easy to
get that engine warm at the best of times! ;-)

Cheers, T i m

[Chris Whelan]

On Fri, 02 Aug 2013 10:32:47 +0100, Mrcheerful wrote:

[..]

> Anything more than minor overheat is likely to bring on head gasket
> failure,
> maybe immediate, maybe a year or two away. Really catastrophic over
> heat takes the piston oil control rings or even compression rings first,
> followed by major internal failure such as crankshaft shells.

Do VX not have an engine protection strategy similar to Ford?

For the last 10 or 15 years (model dependent), Ford engines stop firing
alternate cylinders at the first stage of over temperature detection. The
cylinders in each cycle that are not firing are cooled by virtue of the
air passing through. A warning light illuminates to advise the driver.

If temperature continues to rise, a second light flashes, and after a
delay to allow safe stopping, the engine is shut down.

I would have thought all main-stream manufacturers would have implemented
something similar by now as it's only done in software.

[Gordon H]

I often wonder why I drive Fords, now I know.

--
Gordon H

Remove Invalid to reply

[Stephen]

On Fri, 2 Aug 2013 20:13:10 +0000 (UTC), Adrian
<tooma...@gmail.com> wrote:

>It'll be a lot hotter than that. 90deg is just into low-speed fan
>territory. I dunno about the Astra specifically, but I checked the spare
>fan switch for one of ours the other day - the high speed kicks in at
>105degC. So - north of there for "too hot".

Somehow coolant temperature came up in conversation a long time ago
and I had sufficient spare time on my hands that I emailed Vauxhall to
ask why they did not have a gauge. I've looked through my old emails
but cannot find the answer that Vauxhall sent me. They did say that
there was a red warning light but I can't remember when it comes on.
You are right that 90C is too low; I think I must have been thinking
of the thermostat, which Haynes tells me opens at 92C.

>Well, no, there wouldn't be. The sender for the light measures the temp
>of the coolant it's submerged in. If a hose bursts, and there's no
>coolant, then the sender isn't measuring the temp of anything...

Is the sensor submerged in the coolant or would it pick up the heat of
the surrounding metal, which would get hotter as the cooling failed?

I thought the same that no coolant = nothing to measure the
temperature of but I think the remarks about gauges were in reply to
another answer, which lead off on a tangent.

>I do like low coolant level lights.

I've never heard of those but they sound useful.

>The fucking great big cloud of sweet-smelling steam that filled their mirrors or enveloped the car could have
>been a clue.

I thought that too but I was told there was no steam.

[Stephen]

On Fri, 02 Aug 2013 21:51:12 +0100, Peter Hill
<peter....@skyshack.demon.co.uk> wrote:

>The overheating can warp the head, that reduces the head gasket
>clamping. Then it takes time.

>If a modern (>1988) SI engine management system detects the engine is
>overheating it will go very rich. Not much use to you but the Northstar
>engine was supposed to be able to cross a desert without any coolant.
>Diesels just run cold anyway.

I shall look up North star on wikipedia.

The repair went well. I managed to drill out the plastic connector
using normal RH drill bits and without needing to recut the threads.
That web site was a big help.

The O-ring that I thought I needed turned out to be a metal washer, so
I would have had those at home if I had known and probably could have
bought a box of them for the price of a single one from the dealer!

The hardest part was disconnecting the radiator hoses to give the
engine and radiator a flush before refilling. Particularly the bottom
radiator hose where there wasn't much room to get to the spring clamp.
I also had a bit of a battle trying to remove the air duct from over
the radiator to get to the top hose.

Since then I have noticed the coolant level is slightly below the cold
mark each morning and I have been topping up.

I cannot see any leaks. Is this anything to be concerned about? The
garage said the coolant looked slightly low when it went in a couple
of months ago (before all this happened) but they too had a good look
around and could not see anything wet.

Thanks,
Stephen.

[Chris Whelan]

On Sat, 10 Aug 2013 07:22:40 +0100, Stephen wrote:

[...]

> Somehow coolant temperature came up in conversation a long time ago and
> I had sufficient spare time on my hands that I emailed Vauxhall to ask
> why they did not have a gauge. I've looked through my old emails but
> cannot find the answer that Vauxhall sent me. They did say that there
> was a red warning light but I can't remember when it comes on. You are
> right that 90C is too low; I think I must have been thinking of the
> thermostat, which Haynes tells me opens at 92C.

How many drivers ever look at the temperature gauge? I'm willing to bet
it's less than 1%.

Modern engines operate safely over a wide temperature range. When
electric fans became standard, dealers were getting lots of calls from
drivers who were worried that their engines were overheating because the
gauge had passed the 'normal' position when in traffic before the fan
started. They didn't understand that was perfectly OK.

To avoid all those false alarms, the gauge systems were modified. In
fact, they are just tri-state indicators now, and not temperature gauges
at all. IOW, if the temperature is within operational limits, the needle
stays dead centre, even though the actual temperature may be varying by
quite large amounts. The whole system could be replaced by three leds,
and would provide just as much (or as little!) information.

>>Well, no, there wouldn't be. The sender for the light measures the temp
>>of the coolant it's submerged in. If a hose bursts, and there's no
>>coolant, then the sender isn't measuring the temp of anything...
>
> Is the sensor submerged in the coolant or would it pick up the heat of
> the surrounding metal, which would get hotter as the cooling failed?
>
> I thought the same that no coolant = nothing to measure the temperature
> of but I think the remarks about gauges were in reply to another answer,
> which lead off on a tangent.

Most engines now have a cylinder head temperature sensor; the operation
of this will be unaffected by the lack of coolant.

>>I do like low coolant level lights.
>
> I've never heard of those but they sound useful.

Systems need to be designed for the average driver, who today is bloody
clueless.

The only sensible approach is to reduce power output in some way as an
over temperature situation develops, flashing a dash light at the same
time, followed by forcing the engine to stop if no action is taken.
Anything less will largely be ignored or abused.

[Chris Whelan]

On Sat, 10 Aug 2013 07:28:07 +0100, Stephen wrote:

[...]

> Since then I have noticed the coolant level is slightly below the cold
> mark each morning and I have been topping up.
>
> I cannot see any leaks. Is this anything to be concerned about? The
> garage said the coolant looked slightly low when it went in a couple of
> months ago (before all this happened) but they too had a good look
> around and could not see anything wet.

Leave it two mornings without topping up, and see if it continues to
fall. It might be that it's 'natural' level is a bit below the mark.

The other possibility is that there is a small airlock that is slowly
dispersing, in which case there will eventually be no drop in level.

[Adrian]

On Sat, 10 Aug 2013 07:22:40 +0100, Stephen wrote:

> Is the sensor submerged in the coolant

Yes.

> or would it pick up the heat of the surrounding metal, which would get
> hotter as the cooling failed?

No.

>>I do like low coolant level lights.

> I've never heard of those but they sound useful.

Quite simple - just a pair of prongs into the header tank. Not submerged?
Light on.

>>The fucking great big cloud of sweet-smelling steam that filled their
>>mirrors or enveloped the car could have been a clue.

> I thought that too but I was told there was no steam.

There was steam. Whether the steam was _noticed_ is another question.

[Adrian]

On Sat, 10 Aug 2013 06:53:38 +0000, Chris Whelan wrote:

> How many drivers ever look at the temperature gauge? I'm willing to bet
> it's less than 1%.

Yes, well... We all know that the average vehicle operator is a fuckwit
who fails to pay attention to the things they should be paying attention
to. Whether those things are inside the dash or outside the windows is
merely fine detail...

> Most engines now have a cylinder head temperature sensor; the operation
> of this will be unaffected by the lack of coolant.

I've never come across a watercooled engine with a temperature sensor for
anything but fluids. You're probably thinking about the separate coolant
temp sensor that some engines have for the engine management ECU. Mostly,
now, it's a single sensor and the ECU controls the gauge and light.

[Chris Whelan]

On Sat, 10 Aug 2013 07:56:08 +0000, Adrian wrote:

[...]

> I've never come across a watercooled engine with a temperature sensor
> for anything but fluids. You're probably thinking about the separate
> coolant temp sensor that some engines have for the engine management
> ECU. Mostly,
> now, it's a single sensor and the ECU controls the gauge and light.

http://bit.ly/1cCaLQN

Note the first line:

"The CHT measures the metal temperature."

and the fact that removal does not require coolant drainage.

[Adrian]

On Sat, 10 Aug 2013 12:11:19 +0000, Chris Whelan wrote:

>> I've never come across a watercooled engine with a temperature sensor
>> for anything but fluids.

> http://bit.ly/1cCaLQN
>
> Note the first line:
>
> "The CHT measures the metal temperature."
>
> and the fact that removal does not require coolant drainage.

Furry muff.

[T i m]

On Sat, 10 Aug 2013 07:53:36 +0000 (UTC), Adrian
<tooma...@gmail.com> wrote:

>On Sat, 10 Aug 2013 07:22:40 +0100, Stephen wrote:
>
>> Is the sensor submerged in the coolant
>
>Yes.
>
>> or would it pick up the heat of the surrounding metal, which would get
>> hotter as the cooling failed?
>
>No.
>
>>>I do like low coolant level lights.
>
>> I've never heard of those but they sound useful.
>
>Quite simple - just a pair of prongs into the header tank. Not submerged?
>Light on.

My 82 Sierra Estate had what I think I remember were called 'Clean
hands indicators' on the dash for low coolant, low washer (float
switches?) and low oil level (an electric dipstick of some sort).

They all worked very well and did indeed keep your hands clean (till
you had to top any of them up etc). ;-)

Cheers, T i m

[RJH]

Quite why all cars don't have this sort of arrangement defeats me. My
brother bought a new Range Rover about 3 years back - low washer fluid
warning light was a cost option. OTOH I gather modern Porsches don't
even have a dipstick.

--
Cheers, Rob

[steve robinson]

The ironic thing being that all the electronics are already in place
for the fluid level warning light, just require the sender unit which
is a few pounds at most . For the cost of a range rover its an insult

[T i m]

Isn't it just. Especially if you have electric side steps and or side
illumination etc.

But then maybe they think that anyone who can afford a Range Rover
wouldn't be interested in a 'Coolant level Low' Indicator?

But no, (Rob), the Sierras (and other makes / models no doubt) 'Clean
hands' indicators were a real boon ... allowing you to at least have
go / no-go check on the basics before you even pulled away (as one was
supposed to do 'regularly' in any case).

Along the same lines (and potentially even more safety related) would
be having tyre pressure indicators fitted as std? How many times have
you looked at a tyre and though 'that looks a bit puddeny', only to
find it was how it was parked? I know I'm very 'aware' of the sort of
feedback you get from tyres (especially when on a motorbike) and have
often stopped to check 'because that speed hump didn't feel quite as
sharp' as I think it should.

Cheers, T i m

[Chris Whelan]

On Sun, 11 Aug 2013 11:11:17 +0100, T i m wrote:

[...]

> Along the same lines (and potentially even more safety related) would be
> having tyre pressure indicators fitted as std? How many times have you
> looked at a tyre and though 'that looks a bit puddeny', only to find it
> was how it was parked? I know I'm very 'aware' of the sort of feedback
> you get from tyres (especially when on a motorbike) and have often
> stopped to check 'because that speed hump didn't feel quite as sharp' as
> I think it should.

By November 2014, all new passenger vehicles will have to have TPMS
installed by the manufacturer; all new types have had to have them
designed in since last November.

[Steve Firth]

T i m <ne...@spaced.me.uk> wrote:
[snip]

> But then maybe they think that anyone who can afford a Range Rover
> wouldn't be interested in a 'Coolant level Low' Indicator?

Oddly enough the Jeep Grand Cherokee has a full complement of these sensors
with a "glass cockpit" approach that only calls the sensor to the attention
if the driver if something is wrong. Given that the JGC is a bargain bucket
car it can't be expensive to add them to the vehicle.

--
<•DarWin><|
_/ _/

[T i m]

Oh, that's a bit of a surprise. I mean, I know you can get them as an
aftermarket solution and imagined that some vehicles might be fitted
with them already but I didn't think they would be made mandatory
across the board so soon (but hopefully a good thing).

This seems to answer all my follow-up questions. ;-)

http://en.wikipedia.org/wiki/Tire-pressure_monitoring_system

Cheers, T i m

p.s. I wonder if they will eventually be programmed into the system to
force the car into 'limp home mode' if the pressure drops below a
certain level (assuming they don't already etc)?

[Chris Whelan]

On Sun, 11 Aug 2013 23:51:06 +0100, T i m wrote:

[...]

> p.s. I wonder if they will eventually be programmed into the system to
> force the car into 'limp home mode' if the pressure drops below a
> certain level (assuming they don't already etc)?

It would be trivially easy to limit maximum speed when low pressure is
detected, and would be better than forcing 'limp-home'.

[Adrian]

On Mon, 12 Aug 2013 06:52:39 +0000, Chris Whelan wrote:

>> p.s. I wonder if they will eventually be programmed into the system to
>> force the car into 'limp home mode' if the pressure drops below a
>> certain level (assuming they don't already etc)?

> It would be trivially easy to limit maximum speed when low pressure is
> detected, and would be better than forcing 'limp-home'.

Are they actually reliable yet?

[Peter Hill]

It's not just speed.

Get a just adequate 140 bhp/ton RWD with 20psi one side and 32psi the
other. Then go try to use it all (WOT 4000>limiter) in a straight line
from 20mph in 1st (21-38mph).

The LSD may not have helped.

Even more sensitive in the wet or snow.

[Chris Whelan]

I don't know. I see them as a bad idea in some ways, and certainly
wouldn't rely on them myself. It's likely that even fewer average owners
will ever bother to do more than glance at their tyres.

I would rather see more roadside checks on vehicle maintenance generally,
with appropriate punishment.

[Chris Whelan]

On Mon, 12 Aug 2013 08:42:05 +0100, Peter Hill wrote:

[...]

>> It would be trivially easy to limit maximum speed when low pressure is
>> detected, and would be better than forcing 'limp-home'.
>>
>> Chris
>>
> It's not just speed.
>
> Get a just adequate 140 bhp/ton RWD with 20psi one side and 32psi the
> other. Then go try to use it all (WOT 4000>limiter) in a straight line
> from 20mph in 1st (21-38mph).
>
> The LSD may not have helped.
>
> Even more sensitive in the wet or snow.

Would the other compulsory electronics being forced upon us not have
helped in the situation you describe?

[Adrian]

On Mon, 12 Aug 2013 07:47:26 +0000, Chris Whelan wrote:

>> Are they actually reliable yet?

> I don't know. I see them as a bad idea in some ways, and certainly
> wouldn't rely on them myself.

And that's the big risk.

> It's likely that even fewer average owners will ever bother to do more
> than glance at their tyres.

Not to mention the proportion that fit the cheapest Chinese ditchfinders
to even relatively new and expensive cars. My mother's 20-something k
mile 207 estate was fitted with Chinese teflon-concrete-blend rubbish by
the franchised dealer, ffs...

> I would rather see more roadside checks on vehicle maintenance
> generally, with appropriate punishment.

Indeed.

[T i m]

On Mon, 12 Aug 2013 07:59:17 +0000 (UTC), Adrian
<tooma...@gmail.com> wrote:

>On Mon, 12 Aug 2013 07:47:26 +0000, Chris Whelan wrote:
>
>>> Are they actually reliable yet?
>
>> I don't know. I see them as a bad idea in some ways, and certainly
>> wouldn't rely on them myself.
>
>And that's the big risk.

I guess as with all things they could (should?) be used as a cross
reference / supplement to the traditional regular visual and (decent /
known) tyre pressure gauge checks? If you check all your tyres and
assuming the remote sensors display the actual pressure (rather than
just a low - good - high output) that at least you will be able to
calibrate the remote sensor system with some straight empirical data.
Now, if you then develop a slow puncture on a trip you would like to
think you would pick that up on the sensor before you felt it
yourself? If the sensor was stuck at that original pressure (or lost
communications and left the display at the original pressure (not a
good design), then it would be down to your senses to detect something
was wrong, just as it would have been without the sensors? I guess the
risk is seeing the sensor read OK and you carrying on regardless (more
for your ordinary drivers, rather than those of us you might 'sense'
such things a bit sooner)?

>
>> It's likely that even fewer average owners will ever bother to do more
>> than glance at their tyres.
>
>Not to mention the proportion that fit the cheapest Chinese ditchfinders
>to even relatively new and expensive cars. My mother's 20-something k
>mile 207 estate was fitted with Chinese teflon-concrete-blend rubbish by
>the franchised dealer, ffs...

Don't. My old Rover (even) came to me with such 'rubber' on and it was
lethal. The PO got a real shock when I gave him a lift in the wet a
few weeks later and to his relief it actually went *round* the
roundabout rather than straight over it as it would with what he had
fitted. ;-)

>
>> I would rather see more roadside checks on vehicle maintenance
>> generally, with appropriate punishment.

>Indeed.

I think that's difficult as sometimes it can just be down to bad luck.
You check your tyres in the morning and you get pulled for a spot
check and on the way you developed a slow puncture? Now, *you* know
you had done all you could but will the officer think the same?

Is that better than letting someone off who has been driving on an
under inflated tyre for ages? <shrug>

Cheers, T i m

[Chris Whelan]

On Mon, 12 Aug 2013 10:21:45 +0100, T i m wrote:

[...]

> I think that's difficult as sometimes it can just be down to bad luck.
> You check your tyres in the morning and you get pulled for a spot check
> and on the way you developed a slow puncture? Now, *you* know you had
> done all you could but will the officer think the same?
>
> Is that better than letting someone off who has been driving on an under
> inflated tyre for ages? <shrug>
>
> Cheers, T i m

If that happened, it's likely that the cause of the puncture would be
visible, and if the other pressures were OK surely that would be a
reasonable defence?

[Duncan Wood]

They seem to be as, if not more, reliable than the tyres we've got.

[T i m]

On Mon, 12 Aug 2013 16:10:49 GMT, Chris Whelan
<cawh...@prejudicentlworld.com> wrote:

>On Mon, 12 Aug 2013 10:21:45 +0100, T i m wrote:
>
>[...]
>
>> I think that's difficult as sometimes it can just be down to bad luck.
>> You check your tyres in the morning and you get pulled for a spot check
>> and on the way you developed a slow puncture? Now, *you* know you had
>> done all you could but will the officer think the same?
>>
>> Is that better than letting someone off who has been driving on an under
>> inflated tyre for ages? <shrug>
>>
>

>If that happened, it's likely that the cause of the puncture would be
>visible, and if the other pressures were OK surely that would be a
>reasonable defence?

Yep, good point, it probably would (in a fair world etc) ... although,
someone could still have been running a tyre with a slow puncture for
some time without getting it seen to? In that case there is a very
good chance the tyre would have been regularly run over then under
inflated for who knows how long? ;-(

And what of those porous ally rims or leaky tyres (my stepdaughter had
ally rims where the ally had corroded under the bead / seal and she
was one of those regular pumper-uppers till I took her to the right
place who cleaned and sealed the rims for her).

But as you say, hopefully the straight 'must have got a slow puncture
since this morning' cases would be seen as what they were (though like
a (just) failed lamp could still get you some black marks)?

Cheers, T i m

[Stuart]

[Stuart]

On Sat, 10 Aug 2013 06:53:38 GMT, Chris Whelan
<cawh...@prejudicentlworld.com> wrote:

>Modern engines operate safely over a wide temperature range. When
>electric fans became standard, dealers were getting lots of calls from
>drivers who were worried that their engines were overheating because the
>gauge had passed the 'normal' position when in traffic before the fan
>started. They didn't understand that was perfectly OK.
>
>To avoid all those false alarms, the gauge systems were modified. In
>fact, they are just tri-state indicators now, and not temperature gauges
>at all. IOW, if the temperature is within operational limits, the needle
>stays dead centre, even though the actual temperature may be varying by
>quite large amounts. The whole system could be replaced by three leds,
>and would provide just as much (or as little!) information.

The only experience I have of a temperature gauge working was on an
L-plate Xantia. As I was driving along the motorway a plastic bag blew
onto the radiator grill. The needle climbed slowly as I drove along
the motorway. I stopped at the next exit and removed the bag and the
temperature fell again but the needle movement was definitely
analogue, not cold, ok, and dangerous. But perhaps a Xantia doesn't
count as modern?