When a rattle develops in the mufflers or catalytic converters, the
time for replacement is nigh. However as a temporary fix to delay the
inevitable expense, Kevin
Kelly has had luck stopping rattles in catalytic converters and
mufflers by drilling a small hole in them and screwing in big drywall
screws with a cordless drill to stop the loose stuff inside from moving
and rattling. (See photo at top right).
Kevin uses a Sears Craftsman "Mechanic's Stethoscope" to listen to the
muffler or cat to determine where the loose items are before drilling a
hole (if you don't have a mechanic's stethoscope you can hold a long
screwdriver to your ear).
Rear muffler from Kevin Kelly's
89 RR showing screws that stopped the rattle for two years.
Catalytic converter cut open to
show solid material that was rattling around inside.
Inserting Copper Wire to Stop Rattles
Kevin's "temporary" fix to stop a loud rattle in the rear muffler on
his 1989 Range Rover Classic actually lasted two years (see photo, above left, of the rear
muffler with the screw inserted that he cut open before he threw it
away). While Kevin has had good luck stopping the rattles in BMW
catalytic converters with screws, he has not had similar luck with
screws in Range Rover cats. The honeycomb catalyst material in the
Range Rover cats is more brittle than the stuff in the BMW cats (see
photos of the loose material in the Range Rover cat that he cut open)
so none of the fixes with screws on the Range Rover lasted more than a
few days (see photos of screws in cat). Kevin did manage to stop the
rattle in the Range Rover cat for a few weeks by shoving about a foot
of copper wire in to the cat (see photo
at right of cat with wire in it).
Muffler and Cat Heat Shield Rattle
Abatement
Range Rovers do not seem to have a problem with the heat shields on the
cats coming loose but if they every do Kevin had been able to stop the
rattle from loose heat shields on BMWs by screwing four big hose clamps
together to make a really big hose clamp. This was wrapped around the
cat and cranked down so the clamp crushed the heat shield and stops it
from moving and rattling.
On my Range Rover 4.0SE, when the heat shield on the center muffler
started to rattle, I was able to use a similar type of fix. This
has already lasted over a year. In my case a clamp made from a
piece of thin steel strip was wrapped around the muffler and tightened
with a nut and bolt. If you need to replace the muffler, see the muffler removal and replacement page.
Aftermarket Replacement Cats and
Mufflers
Since the Range Rover catalyst
material is so brittle, it may be possible (though illegal and not
recommended) to crack it in to small
pieces and shake it all out, but the best solution is to replace
the
worn out cat with a new one (see photo at right of new aftermarket cat
beside old genuine one).
Depending on model year, you may be able to replace only the cat that
is rattling (as Kevin could on his 89 RR). On some model years,
however, you may have to replace them as a pair since they are welded
together as a single unit. Kevin found an aftermarket bolt
in "plug and
play" converter
for under $200.
When purchasing cats and mufflers, care may be needed if you opt for
one of the totally "generic" replacements to ensure that the cats are
up out of the way and neither the cats/mufflers nor the steel tubing
reduces clearance to either the chassis or the ground. However most
aftermarket units now available which are sold specifically for Range
Rovers are specially configured for the vehicle.
Information on low cost aftermarket sources for exhaust components
including mufflers and catalytic converters is provided on the Parts Sources page.
