Garage told me twice not to worry about my Astra revving itself wild on a cold start… now the check engine light played peekaboo. Help?
My 2006 Vauxhall/Opel Astra H 1.8 automatic revs on its own after a cold start, bouncing between 1,000 and 2,500 rpm for about 90 seconds. After that, it runs perfectly fine. This has been happening for a few months now, mostly during the warmer UK weather. I’ve taken it to the garage twice, had diagnostics run, and both times they said not to worry, apparently, some rev fluctuation on cold starts is normal for an older car, especially between 1,000–2,000 rpm. So I let it go.
But yesterday, after a 30-minute morning drive (with the usual revving), I parked for three hours, then started the car again, no revving this time, since it wasn’t a cold start but the check engine light came on. I stopped after about 5 minutes and called the garage to book it in. When I restarted the car after that call, the light had turned off. Now I’m second-guessing whether I even need the appointment. It’ll cost around £50 for another diagnostic, but without the warning light on, I feel like I’m just going back with the same revving issue they’ve already told me to ignore twice.
Does anyone have any idea what might actually be going on?