Discovery 2 and Defender
Repairing a warped Td5 exhaust manifold
Has the Td5 engine in your Discovery 2 or Defender developed a high-pitched whistle or squeal from the engine bay? If it has, the chances are that your exhaust manifold has become warped and will have broken a stud or two – or pulled the studs from the cylinder head. The squeal that one hears is the exhaust gases being expelled under high pressure through the tiny gap that has opened up between the manifold and the cylinder head.
The temperatures generated within the Td5 exhaust manifold can be quite extreme. When the engine is driven very hard or if it’s highly tuned or perhaps doing a lot of heavy towing, the temperatures become so great that the tendency for the manifold to warp is stronger than the studs holding it in place. It is most common for a stud at the front or rear of the engine to break first. A tell-tale sign will be sooty deposits around the manifold and cylinder head. There might also be a drop in performance, lower power and reduced fuel economy.