Partially clogged condenser is worth checking on a 70k Discovery especially if it has been driven in dusty conditions. Restricted airflow through the condenser causes exactly this speed dependent cooling pattern.
Feeling heartbroken for a day after walking away from a Patrol you loved is completely understandable. Feeling relieved for years afterward because you avoided a compromised 95k purchase is the better outcome every time.
Nervousness about an internet shop is understandable but Sharjah transmission specialists who handle 7G Tronic units regularly are genuinely skilled. Asking about their warranty policy before booking tells you a lot about their confidence in their own work.
