Bad rattle on start-up
My daughter’s 2012 Corsa Ecoflex 1.0 has a bad rattle from the engine on cold starts after standing overnight or for a few hours. The rattle only lasts for a couple of seconds and sounds like valve lifter noise.
We have only just bought the car and it only has 16,500 miles on the clock. When we viewed the car the engine was warm and the rattle doesn’t happen once the engine has been restarted after a short time, so we didn’t notice anything untoward until the next day.
I changed the oil and filter using the recommended 5W-30 fully-synthetic oil and a genuine Vauxhall filter, hoping that this would cure the problem. The noise is still there, but I did notice that there was hardly any oil in the oil filter housing when I removed the filter cap (there is a spring-loaded plunger on the bottom of the housing, but I’m not sure what it is for). Graham Chatterton
When the cap on the oil filter housing is undone, the oil will drain down as it is lifted. This is to allow the filter housing to be drained easily when the oil and filter are changed. This is the function of the spring-loaded plunger at the bottom of the oil filter housing.
The most likely source of the sound you are hearing is either a sticking hydraulic valve follower or a timing chain. With such a low mileage, I would not expect the timing chain to be worn, so the most likely scenario is that, having been used for short journeys, the hydraulic tappet blocks are sticking.
Having just changed the oil and filter without any improvement, I would suggest using an additive such as Wynn’s Hydraulic Valve Lifter Treatment, available from autosessive.com. This could also help if the problem is a sticking timing chain tensioner.
As you have only just bought the vehicle, if this was from a dealer I would be inclined to make them aware of the problem. If it turns out to be more serious, you will have already noted the fault. The fact that the engine had been started before you looked at the vehicle does make me wonder if the seller was aware of the issue.