98 Grand Marquis rattle in exhaust system

Some of the problems....

Most common is a rusted heatshield or band clamp... the only way is to look
and listen.....

Also possible.... broken catalyst monolith orruted baffle in the muffler....
again, there is a need to look and listen.

The internet is an aid - not a replacement....

"mstrspy" <blank.TakeThisOut@verizon.net> wrote in message
news:6rr9m25l1tglob2cc4b0gi5r914kfpmuk6@4ax.com...
> My 98 Grand Marquis makes a rattleing noise when the engine runs. It
> would seem that there is something loose inside the muffler. Anyone
> know what it could be? It is not a rattle due to going over bumps. It
> ocurs due to pressure in the exhaust system.
 >> Stay informed about: 98 Grand Marquis rattle in exhaust system 

Some of the problems....

Most common is a rusted heatshield or band clamp... the only way is to look
and listen.....

Also possible.... broken catalyst monolith orruted baffle in the muffler....
again, there is a need to look and listen.

The internet is an aid - not a replacement....

"mstrspy" <blank.RemoveThis@verizon.net> wrote in message
news:6rr9m25l1tglob2cc4b0gi5r914kfpmuk6@4ax.com...
> My 98 Grand Marquis makes a rattleing noise when the engine runs. It
> would seem that there is something loose inside the muffler. Anyone
> know what it could be? It is not a rattle due to going over bumps. It
> ocurs due to pressure in the exhaust system.
 >> Stay informed about: 98 Grand Marquis rattle in exhaust system 

mstrspy wrote:
> The broken catalyst monlith is a god bet becase I get a check engine
> lijght that indicates insuficient catalyst.
>

Or one of the air tubes going into that cat is rotted off or broken,
rattling? Someone please stop me if I am incorrect, but I think the
oxygen IS the catalyst? Which if correct would lead me to believe not
enough air is getting into the cat (insufficient catalyst)? Definately
needs a visual inspection. I had to fix these years ago, forget if
there were any codes involved.
 >> Stay informed about: 98 Grand Marquis rattle in exhaust system 

mstrspy wrote:
> The broken catalyst monlith is a god bet becase I get a check engine
> lijght that indicates insuficient catalyst.
>

Or one of the air tubes going into that cat is rotted off or broken,
rattling? Someone please stop me if I am incorrect, but I think the
oxygen IS the catalyst? Which if correct would lead me to believe not
enough air is getting into the cat (insufficient catalyst)? Definately
needs a visual inspection. I had to fix these years ago, forget if
there were any codes involved.
 >> Stay informed about: 98 Grand Marquis rattle in exhaust system 

The catalyst is a small amount of noble metal inside the converter; it
promotes, but does not combine in the oxidation process.
In the early days of emission controls Ford had external air delivered to
the catalytic converters and a pump that provided it (called 'thermactor').
You will find that in my 1985 LTD, but it has been abandoned long before the
1998 model of the OP came out.

<sleepdog.DeleteThis@optonline.net> wrote in message
news:1164307652.826938.130300@f16g2000cwb.googlegroups.com...
> Or one of the air tubes going into that cat is rotted off or broken,
> rattling? Someone please stop me if I am incorrect, but I think the
> oxygen IS the catalyst? Which if correct would lead me to believe not
> enough air is getting into the cat (insufficient catalyst)?
 >> Stay informed about: 98 Grand Marquis rattle in exhaust system 

The catalyst is a small amount of noble metal inside the converter; it
promotes, but does not combine in the oxidation process.
In the early days of emission controls Ford had external air delivered to
the catalytic converters and a pump that provided it (called 'thermactor').
You will find that in my 1985 LTD, but it has been abandoned long before the
1998 model of the OP came out.

<sleepdog.RemoveThis@optonline.net> wrote in message
news:1164307652.826938.130300@f16g2000cwb.googlegroups.com...
> Or one of the air tubes going into that cat is rotted off or broken,
> rattling? Someone please stop me if I am incorrect, but I think the
> oxygen IS the catalyst? Which if correct would lead me to believe not
> enough air is getting into the cat (insufficient catalyst)?
 >> Stay informed about: 98 Grand Marquis rattle in exhaust system 

The broken catalyst monlith is a god bet becase I get a check engine
lijght that indicates insuficient catalyst.

On Thu, 23 Nov 2006 06:28:45 GMT, "Jim Warman"
<mechanic DeleteThis @telusplanet.net> wrote:

>Some of the problems....
>
>Most common is a rusted heatshield or band clamp... the only way is to look
>and listen.....
>
>Also possible.... broken catalyst monolith orruted baffle in the muffler....
>again, there is a need to look and listen.
>
>The internet is an aid - not a replacement....
>
>"mstrspy" <blank DeleteThis @verizon.net> wrote in message
>news:6rr9m25l1tglob2cc4b0gi5r914kfpmuk6@4ax.com...
>> My 98 Grand Marquis makes a rattleing noise when the engine runs. It
>> would seem that there is something loose inside the muffler. Anyone
>> know what it could be? It is not a rattle due to going over bumps. It
>> ocurs due to pressure in the exhaust system.
>
 >> Stay informed about: 98 Grand Marquis rattle in exhaust system 

The broken catalyst monlith is a god bet becase I get a check engine
lijght that indicates insuficient catalyst.

On Thu, 23 Nov 2006 06:28:45 GMT, "Jim Warman"
<mechanic.DeleteThis@telusplanet.net> wrote:

>Some of the problems....
>
>Most common is a rusted heatshield or band clamp... the only way is to look
>and listen.....
>
>Also possible.... broken catalyst monolith orruted baffle in the muffler....
>again, there is a need to look and listen.
>
>The internet is an aid - not a replacement....
>
>"mstrspy" <blank.DeleteThis@verizon.net> wrote in message
>news:6rr9m25l1tglob2cc4b0gi5r914kfpmuk6@4ax.com...
>> My 98 Grand Marquis makes a rattleing noise when the engine runs. It
>> would seem that there is something loose inside the muffler. Anyone
>> know what it could be? It is not a rattle due to going over bumps. It
>> ocurs due to pressure in the exhaust system.
>
 >> Stay informed about: 98 Grand Marquis rattle in exhaust system 

mstrspy wrote:
> How do I inspect this? If I crawl under he car, would I be able to see
> the broken piece or is it internal?
>

Sorry, Happy Traveler shot my theory full of holes for your car/year.
Figures, since when I fixed this problem it was on a 1986 Ford Escort.
 >> Stay informed about: 98 Grand Marquis rattle in exhaust system 

How do I inspect this? If I crawl under he car, would I be able to see
the broken piece or is it internal?

On 23 Nov 2006 10:47:32 -0800, sleepdog.TakeThisOut@optonline.net wrote:

>mstrspy wrote:
>> The broken catalyst monlith is a god bet becase I get a check engine
>> lijght that indicates insuficient catalyst.
>>
>
>Or one of the air tubes going into that cat is rotted off or broken,
>rattling? Someone please stop me if I am incorrect, but I think the
>oxygen IS the catalyst? Which if correct would lead me to believe not
>enough air is getting into the cat (insufficient catalyst)? Definately
>needs a visual inspection. I had to fix these years ago, forget if
>there were any codes involved.
 >> Stay informed about: 98 Grand Marquis rattle in exhaust system 

How do I inspect this? If I crawl under he car, would I be able to see
the broken piece or is it internal?

On 23 Nov 2006 10:47:32 -0800, sleepdog.RemoveThis@optonline.net wrote:

>mstrspy wrote:
>> The broken catalyst monlith is a god bet becase I get a check engine
>> lijght that indicates insuficient catalyst.
>>
>
>Or one of the air tubes going into that cat is rotted off or broken,
>rattling? Someone please stop me if I am incorrect, but I think the
>oxygen IS the catalyst? Which if correct would lead me to believe not
>enough air is getting into the cat (insufficient catalyst)? Definately
>needs a visual inspection. I had to fix these years ago, forget if
>there were any codes involved.
 >> Stay informed about: 98 Grand Marquis rattle in exhaust system 

The defective catalytic converter has nothing to do with your engine's
performance or fuel economy. It has to do with the air we all breathe. The
code you see is from an 'open loop monitor' of the exhaust stream. The
engine management computer does not use it for anything, except for letting
you (and the emissions inspector perhaps) that something is amiss.

"mstrspy" <blank.TakeThisOut@verizon.net> wrote in message
news:evpem2tsmn9jrhi96sob22jkr8tn8s393l@4ax.com...
> It sure seems suspicious that I get a rattle in the exhaust system
> when the engine is running and I get the code "insufficient catalyst".
> Is there an O2 sensor tht could be broken and flapping in the breeze?.
> This car has 2 cats and I hoping that I don't need t replace both.
> By the way, the engine runs great and gets good fuel economy,
> insufficinet catalyst or not.
 >> Stay informed about: 98 Grand Marquis rattle in exhaust system 

The defective catalytic converter has nothing to do with your engine's
performance or fuel economy. It has to do with the air we all breathe. The
code you see is from an 'open loop monitor' of the exhaust stream. The
engine management computer does not use it for anything, except for letting
you (and the emissions inspector perhaps) that something is amiss.

"mstrspy" <blank RemoveThis @verizon.net> wrote in message
news:evpem2tsmn9jrhi96sob22jkr8tn8s393l@4ax.com...
> It sure seems suspicious that I get a rattle in the exhaust system
> when the engine is running and I get the code "insufficient catalyst".
> Is there an O2 sensor tht could be broken and flapping in the breeze?.
> This car has 2 cats and I hoping that I don't need t replace both.
> By the way, the engine runs great and gets good fuel economy,
> insufficinet catalyst or not.
 >> Stay informed about: 98 Grand Marquis rattle in exhaust system