Have just bought a 1990 740 Turbo, and noticed a rattle in all gears (4 sp w/OD) at around 1750 RPM. It sounds like a "loose tin" kind of rattle, almost like a loose clamp on muffler or something. It's difficult to locate, bc only happens when driving. Any ideas? The car is otherwise A-1, running very well in all respects. TIA.
skid
Check the heat shield above the tail pipe.
Also check first exhaust box if car has catalyser fitted as they often fall apart after several years.
All the best, Peter.
700/900/90 Register Keeper, Volvo Owners Club (UK).Heat shield a very common thing about the 740 all years Regards Nightmare
"skid" skrev i meddelandet news: snipped-for-privacy@4ax.com...
Heat shield is as others said a likely candidate. Also there is a very long metal "hose" that routes warm air to the intake that if not secured makes buzzy rattly noises. Also, a failing catalytic converter will rattle. Finally, check the entire exhaust system for integrity.
Thanks for all the input - I can't find anything particularly loose in there - so I'm contemplating taking it in (thankfully I have someone I can trust!), but just wondering why it might only happen at 1750 RPMs...that's a curious one for me. TIA.
skid
If the engineer in the family was writing this she would probaly start babbling on about harmonics and such stuff. Look at that heat shield first. A decent repair shop will have a set of remote microphones that they can position around the car and selectively listen as the car is driven.
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