V50 1.8s 'reduced performance' notification no fault code

[Add7525]

Hi there, as per this posts title the 'reduced performance' notification has started appearing. It first appeared a week ago towards the end of a 35min drive at circa 50 -70mph. It didn't come during the week on the 30min low speed commute to work but it's just come on again today twice. Once at the very end of a 1hr drive to my sisters (mainly A roads) and on the return journey about 3hours later it came up just after we left. Whilst at my sisters my brother in law plugged in his fault code reader in but no faults were displayed.
When the notification comes up there is no noticeable change in performance however over the last couple of weeks we have noticed when diving at around 60 to 80mph the car seems to surge very subtly - i also have a classic car and if I didn't know better would describe the sensation as 'hunting'. Any thoughts?

It was serviced 2months ago and has been driving a lot more smoothly than it did before the service up until now.

[jeffmasson]

Originally Posted by Add7525

Hi there, as per this posts title the 'reduced performance' notification has started appearing. It first appeared a week ago towards the end of a 35min drive at circa 50 -70mph. It didn't come during the week on the 30min low speed commute to work but it's just come on again today twice. Once at the very end of a 1hr drive to my sisters (mainly A roads) and on the return journey about 3hours later it came up just after we left. Whilst at my sisters my brother in law plugged in his fault code reader in but no faults were displayed.
When the notification comes up there is no noticeable change in performance however over the last couple of weeks we have noticed when diving at around 60 to 80mph the car seems to surge very subtly - i also have a classic car and if I didn't know better would describe the sensation as 'hunting'. Any thoughts?

It was serviced 2months ago and has been driving a lot more smoothly than it did before the service up until now.

try cleaning the connectors on the ecm with contact cleaner its very easy to get to on the 1.8 it next to the battery box on the left hand side. disconnect the battery negative terminal then there is a peg type clip on the top the cover on the side of the battery box just push the middle in and it will pull out then unclip the cover spray the 3 connectors and the sockets they fit in to.

also doing the same with the cem can help with lots of issues

[Orca2]

Check your aircon is not on at the time it shows the message, mine was doing this and the problem turned out to be a seized aircon pump, the clutch burnt out because the aiux belt was still trying to drive the pump.

[Add7525]

Thanks guys - I will give those things a look when my daughter decides to go to sleep and I get a minute! Interesting my wife has said it happened not long after she put the aircon on, but I've just been out in it this morning and put the aircon on, definitely working but no ' reduced performance' sign popped up suggesting it's not the aircon pump / clutch unless it can be intermittent? Will report further in due course .

[Add7525]

Hi guys,

Further to my previous posts the 'Reduced engine performance' is now popping up more and more often. No every day it is driven but every time we drive any distance. Today it came on about 25mins into a 1.5hr drive. and then when heading home came on after 5mins. All the connectors have been wiggled and sprayed with contact cleaner but it made no difference.

However, the main thing that is becoming more and more noticeable is the sensation of surging that i mentioned previously. Its now happening constantly - with and without the 'reduced engine performance' being displayed. The surging is noticeable in all gears between about 20mph up to 70mph. Over 70mph you don't really notice it, and it is more noticeable in 2nd and 3rd gears between say 20 and 50mph.

Plugged in to my brother in laws code reader and again no faults recorded.

Any ideas?

cars done 53000miles.

cheers adam

[Add7525]

p.s. thought i would add that although this 'surging' happens both when accelerating and when at constant speed but is much more noticeable at constant speed.

Also i suppose the 'surging' could also be described as 'hesitation'

[jeffmasson]

Originally Posted by Add7525

p.s. thought i would add that although this 'surging' happens both when accelerating and when at constant speed but is much more noticeable at constant speed.

Also i suppose the 'surging' could also be described as 'hesitation'

have you tried cleaning the connectors on the ecm?

[Daim]

Don't bother cleaning the connectors around the ECM. Remove battery cable, remove throttle body, clean that thing up and then refit.

Your problems will then to a 95% degree disappear...

[Add7525]

Jeff, I had cleaned the connectors when you first mentioned it but if anything it made it worse. However gave it another go last sunday and gave them a really good squirt of WD40 (didn't have proper contact cleaner), wiped off excess and plugged back in and...... since doing that its been behaving itself. haven't done a long drive yet but so far so go and no surging recently.

Daim - haven't taken the throttle apart but did disconnect the air pipe and opened the valve and its clean as a whistle!

I will keep you all posted of any further developments

Cheers Adam

[Add7525]

The problem still persists. The last 3 days have seen the hesitation, pausing, surging (call it what you will) continue every time we drive and if anything its getting worse. The 'Reduced engine performance' notification is coming up every time we drive now as well. Sometimes not for a while, but eventually it does.

So i need some new ideas as to the cause of the problem. All the connectors have been cleaned x3 times with contact cleaner and it makes no difference.

Ive obviously been trying to do a lot of research before thinking about putting it into the garage.

my current thoughts are:

1. issue with throttle pedal (the problem alway seems to be in the pedal position that i would call 'normal' driving / throttle application zone - perhaps the sensor zone is worn leading to variations in current being sent to the throttle.
2. The throttle position sensor (potentiometer) - (the throttle its self looks very clean and moves freely)
3. The Exhaust Gas Recirculation Valve (EGR) - I'm not 100% sure petrols engines have this but from what i can see they do. Certainly the sensation is like the engine isn't getting enough oxygen intermittently which is killing off the combustion

I would love to know peoples thoughts -

I intend to take some bits off tomorrow and take a look at them. I would love to know. a) is it possible to take the throttle sensor off without taking the hole throttle body off and b) where exactly is the EGR valve and is there anyway in which it can be tested?

Adam