vectra idle speed - mick_the_mod
Help.. Last week my exhaust started blowing , and while on the way to the exhaust fitters i was stuck in traffic, and the idle speed started to ramp from 900>2000 continually, i put this down to the exaust at first, but it has continued to rev ,only when the engine is hot,
vectra idle speed - Dynamic Dave
I take it the engine management light on the dash hasn't come on?
First thing I would do is disconnect the battery for five mins to see if it will reset the ECU. Don't forget to dig out your radio code before doing so though.
vectra idle speed - Snakey
I had a very similar problem on my 2.0 Omega, which may be a similar engine. Basically the engine revs fluctuated up and down when the engine reached normal temparature.

I traced it to the EGR(Exhaust Gas Recurculation) valve being seized closed, I took this out and after much tapping and cleaning released it and all worked well after that - I then got a second hand one from a scrappy as they only seem to last 30-40K without coking up.

You can test this by unplugging the rubber air pipe in the back of the valve - if the engine settles down with this unplugged this may well be your problem.

vectra idle speed - steveb
Another common problem is the Idle Air Control (IAC) Valve which gets gummed up with oil and deposits on this engine. It can be cleaned successfully, but often needs replacing altogether. I had this problem twice on the same Vectra, and got rid of it in the end because of it ...!

Vauxhall do a breather system mod on the Vectra, probably the same on the Omega, but as I say, wasn't a long term solution.

vectra idle speed - Pete R

This link shows you how to clean the idle valve
vectra idle speed - mick_the_mod
I had already cleaned the IAC but decided to try again, after your advice, and also sprayed WD40 into the IAC motor which seemed to free the actuator, this appears to have solved the problem, thanks for you input. I will update you to any changes.

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