Fossy
New Member
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I thought i'd post this as a separate post for anyone who has/or is experiencing this problem.
The knocking noise on pull away..............I have herd this a few times in the past from people I know who have owned them too but didn't connect. Get this ..............
Maserati Exhaust manifolds are twin skinned, and the inner skin detaches from the outer skin after a number of years and causes a knocking or rattling which sounds like the exhaust is knocking on something metallic under the car. Exactly the noise i'm getting!
Attempts to rectify the problem in the past have included trying to strip the inners out, drilling small holes and welding the inner back etc, which has stopped it for a time, then it returns. It happens on short journey cars mainly due to condensation between the inner and outer parts causing the connecting spots to erode possibly, or just the original spot welds were infact done badly, or the pulses within the headers destroys the welds and causes them to fail;, who knows ?. Once the exhause warms up, the noise decreases due to expansion of the inner lining, but I still got a little knocking even when warm. When the car was in N when cold, it would rev cleanly without noise, but when 1st or REVwas selected, I'd pull away and the bloody knocking would start. Reason was explained to me - in N, there is no forces or load from engine to rear wheels, but in gear, when you pull away, the engine is forcing the whole transmission to turn the wheels which causes the engine to twist or tilt the opposite way to the output direction. The exhausts are pretty rigid and bolted together throughout their length, and the slight twist causes the outer and inner parts of the manifold to be able to make enough contact to generate this noise, but not when in neutral.
Ok, a new manifold is £2000+VAT each side, cough splutter ........... and same problem potentially down the line. After market one is single skin so fit and forget ???? or just put little crimps in the header tubes where not noticed through to the cat, hey prestow, the outer and inner are now as one and technically the noise should cease. I reasearched this problem through Maserati service and they agreed with me that this is excactly the cause of the noise, so anyone else getting a tapping/knocking noise when cold on pullaway .........you now know.
The knocking noise on pull away..............I have herd this a few times in the past from people I know who have owned them too but didn't connect. Get this ..............
Maserati Exhaust manifolds are twin skinned, and the inner skin detaches from the outer skin after a number of years and causes a knocking or rattling which sounds like the exhaust is knocking on something metallic under the car. Exactly the noise i'm getting!
Attempts to rectify the problem in the past have included trying to strip the inners out, drilling small holes and welding the inner back etc, which has stopped it for a time, then it returns. It happens on short journey cars mainly due to condensation between the inner and outer parts causing the connecting spots to erode possibly, or just the original spot welds were infact done badly, or the pulses within the headers destroys the welds and causes them to fail;, who knows ?. Once the exhause warms up, the noise decreases due to expansion of the inner lining, but I still got a little knocking even when warm. When the car was in N when cold, it would rev cleanly without noise, but when 1st or REVwas selected, I'd pull away and the bloody knocking would start. Reason was explained to me - in N, there is no forces or load from engine to rear wheels, but in gear, when you pull away, the engine is forcing the whole transmission to turn the wheels which causes the engine to twist or tilt the opposite way to the output direction. The exhausts are pretty rigid and bolted together throughout their length, and the slight twist causes the outer and inner parts of the manifold to be able to make enough contact to generate this noise, but not when in neutral.
Ok, a new manifold is £2000+VAT each side, cough splutter ........... and same problem potentially down the line. After market one is single skin so fit and forget ???? or just put little crimps in the header tubes where not noticed through to the cat, hey prestow, the outer and inner are now as one and technically the noise should cease. I reasearched this problem through Maserati service and they agreed with me that this is excactly the cause of the noise, so anyone else getting a tapping/knocking noise when cold on pullaway .........you now know.
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