Symptoms
An exhaust blow, ticking or chuffing from under the bonnet/hood area. Affects the passenger side on UK cars or the Drivers side on US and European SL’s when the engine is running.
Vehicle affected
Any SL with a V8 engine
Diagnosis
This problem is especially common on late model V8’s from 1986-89 – commonly the 420 and 500SL. The sound may diminish as the manifolds and headers expand, and as the engine reaches operating temperature.
The exhaust manifolds often develop a crack around the EGR valve area .This problem is extremely common on all V8 SL’s to some degree.
The Cure
Rather than remove and replace the manifold (a very expensive exercise), the SL shop have developed a method of braze repairing the manifold in situ. This repair is both permanent and very cost effective.