Flashing glow plug light has come up on the dash a few times over the last weeks, then it doesn't show for several days.

When it is on I have restricted performance only in second gear. Revs are cut before I would usually change up. When I change up I have no restriction.

Put the code reader in it and there are zero codes.

No idea where to start! Any ideas welcome.

What engine?

Apologies, 1.6Tdi.

BUMP! Anyone? I appreciate the absence of codes makes it difficult.

I only have a cheap P code reader. Could their be codes in other modules that a better reader would read?

(BTW restricted mode is not just in second gear. I hadn't driven anywhere where I was getting above 3K revs (the restricted point) in higher gears).

22 hours ago, reg091 said:

I only have a cheap P code reader

I honestly suggest getting yourself a ODBEleven reader. Getting generic readers causes more frustration and problems than it resolves. You then just need to download the app for iOS or Android. Even if you get just an ODBEleven Gen2 dongle (ideal for the MK3 Octavia) - £52.89; this can read codes properly and give you better diagnostic output.

https://obdeleven.com/products/nextgen-obdeleven-device

Thanks for the recommendation. I will check it out.