Strange engine noise from a V6 ?
I have noticed a noise coming from the engine of my V6, which is only apparent on acceleration, normally in a high gear at low speed. It's not a grinding noise (quite hard to describe, sorry), but more of a rattling noise, similar to a loose exhaust manifold heat shield I guess, but it's not a vibrating noise!
For example, accelerating at 2,500 rpm in sixth gear, this noise can be heard. I would say it's more of a scraping noise, definately coming from the engine. It's quite hard to trace, as when the car is revved at standstill or on idle, the noise cannot be heard. I have also tried driving the car at a high speed in low gear, and there is no noise. For example, driving at 60mph in 3rd gear - it sound perfecly healthy - OK it's revving quite high, but there are no nasty noises.
So basically what I am hearing is a scraping noise coming from the engine when accelerating in a high gear. The only real way to describe it is imagining a loose heatshield, that is ever so slightly touching the exhaust!
Any ideas anyone? Are the manifold shields prone to coming loose on these. Haven't had a real chance to look yet, but will have a look sometime this week!
Any help appreciated as always!
Alfa Romeo 156 3.0 V6 24v Lusso (2000)
Lancia Delta HF Turbo IE (1991) - Rust In Peace !