My suggestion is in the morning when stone cold, have someone stand behind the car near exhaust. start it up and give it a few good revs up to 5,000 rpm. If you notice black/blue smoke than you have problems with the valve stem seals. If the valve stem seals go hard, over night oil will run between the stem seals and the valves and upon start up it will burn the oil off. When u reverse and drive off normally u wont notice it because generally you drive slowly until it warms up.

Before any of you say, you will damage your motor revving at that rpm when cold, yes it isnt good, but thats how you check for valve stem seals.....

Give it a go, if it does happen, book your car in with a dealer for an over night start and then they will do the same test......

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