Engine Doesn't Rev Beyond 5400RPM

No fault or engine management lights have appeared on my dashboard. As for whether a fault light exists or not, good question as I vaguely remember reading my owners manual and it didn't mention anything about a fault light. Will check in a bit. However when scanned for faults in December during the service, I was told that a temperature sensor fault came up, which is why I replaced it then.

But in answer to your other questions, the speedometer works fine, the ABS light flashes as normal, and disappears along with the other lights after one second.
 
I doubt it's an O2 sensor, since they are used to alter the map and for closed loop running at steady state. Can you get it to rev higher by pumping the throttle?

An O2 sensor fault would be logged but may not trigger the fault light. Once you've tried the diagnostic steps in this page it may be wise to see if the ECU has anything to say. Three options:
-Pay a dealer to read it.
-Set yourself up with VAG-COM.
-Find someone with VAG-COM.
 
Keep your suggestions coming guys. :)

What I will do first, is check the air filter area for any blockages. If there's no actual blockage, I think the next thing I will do is get it scanned for faults I presume? Fault scan carried out in december flagged up the temperature sensor, which I've since replaced.
 
I profess to know nothing about these cars but if they have coilpack ignition then those can go wrong on VAG cars (its a rubbery electrical thing that goes over the spark plug).

A dodgy coil pack could do what your experiencing as one of the spark plugs would fail to fire or fire intermittantly, can buy replacement bosch ones from eurocar parts etc.
 
I've been told that if a O2 sensor is shown to be at fault, that it could be another fault that is triggering it? Is that true?
 
BigglesPiP said:
One step at a time, shelve that thought.
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Will inspect the air filter area for blockages this weekend, if I have no luck then I will get my local VAG Specialist to do a fault scan.

But I will keep you guys updated.

Cheers Biggles and everyone who has contributed so far.
 
Tomsk said:
My guess is the Lambda/oxygen sensor on the catalyst.
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Mackass said:
I've been told that if a O2 sensor is shown to be at fault, that it could be another fault that is triggering it? Is that true?
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Possible but unlikely. VAG told me I needed a new lambda when the crank sensor went. I'm not a qualified motor tech but it seemed obvious even to me that when the timing is all to **** it's likely to be a false alarm.

O2 sensor usually trips the emissions/engine check light. None of the other sensors that failed on mine (MAF, Coolant Temp, Crank position) ever did.

/EDIT :
Coil is unlikely. The infamously bad ones were the per cylinder units on the 1.8 20Vs. The AKL 1.6 has a single coil with HT leads.
 
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Well guys, I made a trip to the petrol station earlier tonight, and inspected the air intake area.

Air filter element and housing were both clean with only a few tiny stones in, the air intake pipe (which connects the air filter housing to the front bumper grill) was also clear, with no blockages whatsoever.

What I did discover though, is that whilst stationary, I was able to rev the engine up to around 6000RPM. Similar, when accelerating in 1st gear, I was able to rev the engine up to around 6000RPM as well. Therefore, I've now discovered that this problem only happens from 2nd gear onwards, and not all gears as I originally thought.

Knowing that the air intake is clear, and that the problem only occurs from 2nd gear onwards, any other suggestions guys? Or would it be best to get it scanned for faults first?
 
Yep, it idles smoothly and constantly at just under 800RPM's.

I heard that peak power for this engine is around 5600RPM, so it currently isn't even reaching that stage!
 
Some more information guys, hope this helps.

This afternoon I made a 100 mile journey and the car was absolutely fine; the engine rev'd beyond 6000RPM in all gears, was full of power and mpg was good.

However, when doing the return journey back at night time, I had the same symptoms as described in my original post; the engine didn't rev beyond 5400RPM from second gear onwards, was lacking in power and mpg was poor.

This means that my missing power issue is intermittent, and is not related to the air intake. Knowing this, any other suggestions guys? Also, this rules out any fuel line related issue doesn't it?
 
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Mackass said:
This means that my missing power issue is intermittent, and is not related to the air intake.
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Yes, pretty much.

Also, this rules out any fuel line related issue doesn't it?
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Not particularly, but I don't think it's a fuel related thing anyway.

With these other symptoms, it could well be an ignition problem. For example, if a coil was intermittently a higher resistance, it would charge more slowly which would become apparent at higher RPM where it fires more often.

Have you tried removing and inspecting a plug? With it having been running, any sign of something could be quite subtle.

I doubt there's an error codes (except maybe a mis-fire) to read, but it could be worth a try, rarely free mind.

Other than that you could try fitting a coil, but looking at the price I'd have the codes read 1st.
 
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