any one out their have this problem I have a rattle in the catalytic
converter took it to the muffler shop and they said its not the converter.
even though I heard noise in it. they cut it off and looked inside and said
nothing was wrong and welded it back up. now its still making noise. is
their something i missed i checked all the piping and the noise is right at
the converter which i have only one.
1988 xj40
134,000 miles
Don
Don,
Its not unusual for a converter to start rattling when it gets old.
Frequently, converters melt inside if the car is run out of gas, or
has a miss that puts more gas into the converter then it can handle.
Its quite common for the pre cat to melt and dump stuff into the second
cats under the car.
On my car, there are two pre cats right after the exhaust manifold,
and two bigger ones under the car.
I would NEVER let anyone weld on my exhaust, as that basically ruins
a very nice, very expensive stainless steel exhaust system.
If its not butchered, the stock exhaust will last the life of the car.
Rust WILL start at welds though.
Jaguar even used nice stainless steel clamps(but not bolts).
The exhaust center section (with cats) needs to be removed to
service things under the car, and its very easy to remove and replace…
Three bolts and it practically falls off…
Why the welding?
It should be a crime to weld on the Jaguar exhaust, and I suspect the
muffler shops like to do so to get even with the owners of such fine
cars, with such great exhaust systems…
‘he will be back now’ they snicker after you leave…
Brett
1990 XJ6
…Date: Tue, 22 Feb 2000 09:26:16 -0700
From: DShanin@cabq.gov
Subject: [modern] catalytic converter noise
Sender: owner-modern@jag-lovers.org
To: modern@jag-lovers.org
any one out their have this problem I have a rattle in the catalytic
converter took it to the muffler shop and they said its not the converter.
even though I heard noise in it. they cut it off and looked inside and said
nothing was wrong and welded it back up. now its still making noise. is
their something i missed i checked all the piping and the noise is right at
the converter which i have only one.
1988 xj40
134,000 miles
Don
Hi Jag Lovers. I have seen many cat convertors that rattle, the internal part
comes loose inside the casing, but the convertor still performs ok. Caused by
many reasons,But eventually the convertor internal parts will brake up with
the vibration and plug up the exhaust system,hence lack of power, To
test this diagnosis bang on the convertor when cold and listen for any
rattle. Glenn 89 VDP 171,900 mls…
same convertor …
Dear Don,
My XJ3.6 '89 (therefore the engine is probably the same as your XJ40)
has also a rattle probably in the catalytic converter.
But the rattle begins only in 5 Minuits after the engine start. Namely,
during the 5 Minuits after the engine start my jag runs very smoothly.
And then the rattle begins when the rev. counter shows the value of
600 rpm as the idle speed, instead of the authentic value of 750 rpm.
I estimate as the reason for the too small value that the ECU model
4410 originally attached to my XJ-S remained not exchannged to the
model 4411 which is authentic for AJ6 with a catalytic converter,
even after a catalytic converter was attached to my xj-s afterwards
in Japan.
If your ECU model is 4411, however, my esitmation is found to be
incorrect. And so I can search for another estimation. Will you
please tell me if your ECU model is also 4410 or not?
Regards
Kenichi