Help with over revving - please

[THeDoctoros]

Hi, can anyone help please? I have a 2005 A4 Cabrio 1.8T and its been over revving for a few weeks now. As soon as it's up to temp rev's start to creep upwards when in neutral from the usual 800 to 900 to 1200 or 1400. It also seems to rev too high when accelerating (or at least it seems to take a long time for the rev's to come back down once the accelerator is released). I have read it could be a breather valve or may CTS (Coolant Temp sensor). Does anyone have any ideas please on what it might be and how to fix it? Thanks.

[calum]

Hi, can anyone help please? I have a 2005 A4 Cabrio 1.8T and its been over revving for a few weeks now. As soon as it's up to temp rev's start to creep upwards when in neutral from the usual 800 to 900 to 1200 or 1400. It also seems to rev too high when accelerating (or at least it seems to take a long time for the rev's to come back down once the accelerator is released). I have read it could be a breather valve or may CTS (Coolant Temp sensor). Does anyone have any ideas please on what it might be and how to fix it? Thanks.

It's the pcv valve, plenty of guides on YouTube showing how to replace it. Replacements available on eBay.

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[calum]

Here's a how to, VW A4: 1.8T PCV components (removal for replacement) - YouTube

eBay parts all seem to be from China so quite a long wait for parts, maybe use the Audi dealers.

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[THeDoctoros]

Thanks calum, much appreciated - the 'how to' you sent seems different to my layout - I've attached a snap of what the pcv valve on mine which I'm hoping will be a much simpler change that the vid.Image-1.jpg

[calum]

Thanks calum, much appreciated - the 'how to' you sent seems different to my layout - I've attached a snap of what the pcv valve on mine which I'm hoping will be a much simpler change that the vid.Image-1.jpg

Are you talking about the large round one at the back of the cylinder head?
Much easier to replace, yes.


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[calum]

https://rover.ebay.com/rover/0/0/0?m...2F311804797631

Here's one.^^^^^^^^

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[THeDoctoros]

Great, thanks again. I bought one just the same about an hour ago, and it looks really straight forward. If it really does fix this issue I'll be over the moon.

[calum]

Great, thanks again. I bought one just the same about an hour ago, and it looks really straight forward. If it really does fix this issue I'll be over the moon.

Both parts can cause this problem, it allows air in and throws the fuelling out causing it to run lean.
I would change the other valve as well because it will fail at some point.
It's inexpensive and simple enough to do.

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[THeDoctoros]

OK, apologies calum, I'm clearly getting a bit confused, which is the 'other' valve please?

[calum]

OK, apologies calum, I'm clearly getting a bit confused, which is the 'other' valve please?

No worries, it's in this video VW Passat PCV valve location and replacement - YouTube