Extended warranties begin coverage 30 days after the sale date, before that it is up to the dealer that sold the contract to repair pre-existing failures. If the buyer asks the salesman about a problem, the salesman will instruct the buyer to wait until the warranty begins, otherwise the repair may be attached to the deal reducing the commission to the salesman.
The oil change done by the dealer prior to purchase may not have been enough to unclog/unstick the VVT servos. Your new oil change may have done the trick.
1 Like
+1
Additionally, the oil that was used previously might not have been of the correct viscosity.
WAG. Broken exhaust valve spring.