Vauxhall Cavalier 16V Air Flow Probs - Jono_99

New to the site, so apologies if this is old hat. A couple of months ago I bought an N plate 16V Cavalier LS (£1,500) which has about 90% of its history, supporting a mileage of only 55,000 miles. It is a reliable, comfortable mile muncher.

On a couple of occasions it 'hiccuped' on the motorway (once every 100 miles) for no discernible reason, and then the engine management system light came on (for about five seconds). I read the manual, and ignored it - second time it happened, I took it to a Vauxhall dealer, who charged me £55 to tell me:
"Traced fault to breather system and idle modification to be replaced. Requires: Breather system, air flow sensor, idle modification kit assymbely".

They wanted £550 for the pleasure, so I pressed on.

It now has 12 more months of MOT, so I am prepared to spend some money. Questions are:

Are there non-franchised dealers who will do this, or is it even a DIY job (capable relatives!)?
Does it all need doing, or just the air flow sensor?

I have sorted the problem (the hiccuping got worse) by cleaning the air filter / sparying some carb cleaning fluid liberally around - did 200 miles yesterday without a problem



Vauxhall Cavalier 16V Air Flow Probs - howy686
Sorry to be a kill-joy but your problem may come back - but There's a lot you can do virtually for free which may sort it out.
The small breather pipe from the cam cover and it's stub onto the inlet manifold (throttle body) may well be blocked solid. You may have to replace the pipe - mine was solid with carbonised crud. Poke out the stub with a sharpened and bent coat-hanger, but don't increase the hole size.
This blockage causes the air-idle valve to gunge-up - this may be revivable with carb cleaner and a lashings of WD40. The valve is mounted on the side of the throttle barrel and acts as a controlled by-pass of the throttle butterfly.
The blockage can also cause hot crankcase fumes to confuse the air flow sensor ('air-mass meter') into giving an error code - there's probably nothing wrong with the device itself.
Vauxhall, bless them, now sell an oil separator ('flame-trap') for around £10 to stop more oily crankcase fumes re-blocking the works. It splices into the thick pipe between the dipstick flange and cam cover.
Somewhere back in this forum there is a link to a site which explains the fault mechanism - maybe someone else can remember the link.
Best of luck....
Vauxhall Cavalier 16V Air Flow Probs - JonM
If you want save yourself £55 in the future you can read the ecu fault codes yourself with nothing more than a paperclip. Check out for details of how to do this for vauxhall engines.
Vauxhall Cavalier 16V Air Flow Probs - Jono_99
Thanks very much for the assistance - had a mucky hour taking most of the pipes off leading to the cam cover and removing variable levels of stuff. Nothing was completely blocked, put nothing was 'as new'. At least I now have the confidence to strip it down in bits when the problem recurs, and have a go at identifying exactly where the problem is.

Apart from that, it continues to be an excellent car

Value my car