mANUAL 62 Corsa 1.4 .50K miles

[Arthur R]

Took the family out for a break this morning.
2 adults and skinny 17 year old and about 20 kilos of baggage.
Everything ok until we joined M60 from M62 -J12 Then a few miles on it started being weird.
Foot hard on the accelerator but not able to reach 65mph with revs never above 3000 (4th or 5th).. It got worse until it was impossible to get above 60mph..foot on the floor
but revs still only 3000 (4th or 5th). When it became too difficult to get it above 50mph in 4th gear I pulled over
RAC man ran diagnostics and found nothing wrong.

I know the M60 is climbing on this stretch but it should make 70.
(I gave it an oil and filter change 3 days ago.)
Any ideas?

Thanks.

[Arthur R]

Post by Arthur R
Took the family out for a break this morning.
2 adults and skinny 17 year old and about 20 kilos of baggage.
Everything ok until we joined M60 from M62 -J12 Then a few miles on it started being weird.
Foot hard on the accelerator but not able to reach 65mph with revs never above 3000 (4th or 5th).. It got worse until it was impossible to get above 60mph..foot on the floor
but revs still only 3000 (4th or 5th). When it became too difficult to get it above 50mph in 4th gear I pulled over
RAC man ran diagnostics and found nothing wrong.
I know the M60 is climbing on this stretch but it should make 70.
(I gave it an oil and filter change 3 days ago.)
Any ideas?
Thanks.

Garage actually carried out the oil and filter chg.

[Peter Hill]

Post by Arthur R

Post by Arthur R
Took the family out for a break this morning.
2 adults and skinny 17 year old and about 20 kilos of baggage.
Everything ok until we joined M60 from M62 -J12 Then a few miles on it started being weird.
Foot hard on the accelerator but not able to reach 65mph with revs never above 3000 (4th or 5th).. It got worse until it was impossible to get above 60mph..foot on the floor
but revs still only 3000 (4th or 5th). When it became too difficult to get it above 50mph in 4th gear I pulled over
RAC man ran diagnostics and found nothing wrong.
I know the M60 is climbing on this stretch but it should make 70.
(I gave it an oil and filter change 3 days ago.)
Any ideas?
Thanks.

Garage actually carried out the oil and filter chg.

Check all the vac hoses for splits. Especially the joiners on pipe that
goes to the MAP sensor. Not sure about Vauxhall but experience with
other GM products says the rubber bits in the engine fall apart and
split. (though that was 55 plate)

Temp fix for any split hose is £2.50 roll of self amalgamating tape from
Screwfix or other hardware store. Internet is full of £15 rolls of the
same stuff for fixing GM inlet duct between air filter and manifold,
while the actual part with air inlet sensor is around £20.

[Arthur R]

[snip]

Post by Peter Hill

Post by Arthur R
Garage actually carried out the oil and filter chg.

Check all the vac hoses for splits. Especially the joiners on pipe that
goes to the MAP sensor. Not sure about Vauxhall but experience with
other GM products says the rubber bits in the engine fall apart and
split. (though that was 55 plate)
Temp fix for any split hose is £2.50 roll of self amalgamating tape from
Screwfix or other hardware store. Internet is full of £15 rolls of the
same stuff for fixing GM inlet duct between air filter and manifold,
while the actual part with air inlet sensor is around £20.

Wouldn't that fault be detected by the RAC guys maguffin?

[Peter Hill]

Post by Arthur R
[snip]

Post by Peter Hill

Post by Arthur R
Garage actually carried out the oil and filter chg.

Check all the vac hoses for splits. Especially the joiners on pipe that
goes to the MAP sensor. Not sure about Vauxhall but experience with
other GM products says the rubber bits in the engine fall apart and
split. (though that was 55 plate)
Temp fix for any split hose is £2.50 roll of self amalgamating tape from
Screwfix or other hardware store. Internet is full of £15 rolls of the
same stuff for fixing GM inlet duct between air filter and manifold,
while the actual part with air inlet sensor is around £20.

Wouldn't that fault be detected by the RAC guys maguffin?

My personal experience was my brother's 55 plate 1.4 Kalos. Wouldn't
pull up hills, difficulty pulling away from junctions when warm. No
codes on scan tool, no pending codes and mil wasn't lit.

A 90 degree rubber elbow joining manifold to MAP sensor had a split in
it. The inlet trunk concertina was in tatters, may have been obstructing
inlet flow. Taped both up, bother reported that it "flew" up a big hill
with 3 and a weeks shopping onboard.

Yes it is odd that the ECU doesn't detect any problem and throw codes.
My 30 year old car with an ECU that is basically a BBC model B, 8bit
CPU, 1Mhz, 16K rom chip for code+maps will detect when airflow meter is
outside expectations of throttle position and engine speed and put it
into limp home mode - usually means I failed to tighten a hose clamp
properly and have installed a massive boost leak, part throttle vacuum
sucks the joint shut. For throttle position (alpha) and engine speed (n)
the manifold pressure should be known. That's how the crudest simple
Alpha-N system works. Map + temp sensor (density) or AFM are extras to
get fuelling within lambda.

Alpha-N crap on hills, tuners love it for drag racing as it's so simples.
http://support.moates.net/theory-alpha-n/

[Roger Mills]

Post by Arthur R
Took the family out for a break this morning.
2 adults and skinny 17 year old and about 20 kilos of baggage.
Everything ok until we joined M60 from M62 -J12 Then a few miles on it started being weird.
Foot hard on the accelerator but not able to reach 65mph with revs never above 3000 (4th or 5th).. It got worse until it was impossible to get above 60mph..foot on the floor
but revs still only 3000 (4th or 5th). When it became too difficult to get it above 50mph in 4th gear I pulled over
RAC man ran diagnostics and found nothing wrong.
I know the M60 is climbing on this stretch but it should make 70.
(I gave it an oil and filter change 3 days ago.)
Any ideas?
Thanks.

The symptoms sound to me like it's detected an emissions fault and put
the engine into 'Limp Home' mode.

But I would have expected to see some evidence of that in the dash
lights and diagnostics.

Is it belching out blue smoke from the exhaust, indicating piston ring
failure?

Is it still playing silly B's - or has it now righted itself?