Should the dealer repair or should I reject?

I recently purchased a used Citroen DS3 THP 1.6. It is a 2012 (61) model with just 15,000 miles. Unfortunately within 2 weeks of ownership, the EML light came on and it has a couple of other issues (erratic idle, cooling fan contantly on regardless of eng temp and a strange intermittent grinding/whining noise when stopped after a fast drive - eg when stoppin on a slip road coming off a dual carriageway).
It was in with the selling dealer last Friday who identified misfire on 2 cylinders (1 & 4), they replaced 4 plugs and 2 coils. however, the erratic idle and intermittent noise are still present. I've recently read that this engine suffers from common issues with coking of inlet valves and the symptoms seems to match. Should i expect EH Citroen to decoke the engine and fully replace any faulty/damaged parts due to the issues manifesting within 2 weeks of ownership?

Asked on 10 August 2016 by will thomas

Answered by Honest John
The intermittent grinding/whining noise is probably the waterpump keeping going to cool the turbo, and that might need replacing. Common on MINI Coopers with the same engine. Also develops timing chain tensioner problems. If not 100% happy, reject the car sooner rather than attempt to do later and possible fail.
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